ModelSim® Reference Manual

Software Version 10.1c

© 1991-2012 Mentor Graphics Corporation

All rights reserved.

This document contains information that is proprietary to Mentor Graphics Corporation. The original recipient of this
document may duplicate this document in whole or in part for internal business purposes only, provided that this entire
notice appears in all copies. In duplicating any part of this document, the recipient agrees to make every reasonable
effort to prevent the unauthorized use and distribution of the proprietary information.
This document is for information and instruction purposes. Mentor Graphics reserves the right to make
changes in specifications and other information contained in this publication without prior notice, and the
reader should, in all cases, consult Mentor Graphics to determine whether any changes have been
made.

The terms and conditions governing the sale and licensing of Mentor Graphics products are set forth in
written agreements between Mentor Graphics and its customers. No representation or other affirmation
of fact contained in this publication shall be deemed to be a warranty or give rise to any liability of Mentor
Graphics whatsoever.

MENTOR GRAPHICS MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MATERIAL
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE.

MENTOR GRAPHICS SHALL NOT BE LIABLE FOR ANY INCIDENTAL, INDIRECT, SPECIAL, OR
CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING BUT NOT LIMITED TO LOST PROFITS)
ARISING OUT OF OR RELATED TO THIS PUBLICATION OR THE INFORMATION CONTAINED IN IT,
EVEN IF MENTOR GRAPHICS CORPORATION HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.

RESTRICTED RIGHTS LEGEND 03/97

U.S. Government Restricted Rights. The SOFTWARE and documentation have been developed entirely
at private expense and are commercial computer software provided with restricted rights. Use,
duplication or disclosure by the U.S. Government or a U.S. Government subcontractor is subject to the
restrictions set forth in the license agreement provided with the software pursuant to DFARS 227.7202-
3(a) or as set forth in subparagraph (c)(1) and (2) of the Commercial Computer Software - Restricted
Rights clause at FAR 52.227-19, as applicable.

Contractor/manufacturer is:
Mentor Graphics Corporation
8005 S.W. Boeckman Road, Wilsonville, Oregon 97070-7777.
Telephone: 503.685.7000
Toll-Free Telephone: 800.592.2210
Website: www.mentor.com
SupportNet: supportnet.mentor.com/
Send Feedback on Documentation: supportnet.mentor.com/doc_feedback_form

TRADEMARKS: The trademarks, logos and service marks ("Marks") used herein are the property of
Mentor Graphics Corporation or other third parties. No one is permitted to use these Marks without the
prior written consent of Mentor Graphics or the respective third-party owner. The use herein of a third-
party Mark is not an attempt to indicate Mentor Graphics as a source of a product, but is intended to
indicate a product from, or associated with, a particular third party. A current list of Mentor Graphics’
trademarks may be viewed at: www.mentor.com/trademarks.
Table of Contents

Chapter 1
Syntax and Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Documentation Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
File and Directory Pathnames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Design Object Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Object Name Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Tcl Syntax and Specification of Array Bits and Slices. . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SystemVerilog Scope Resolution Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Specifying Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Environment Variables and Pathnames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Name Case Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Extended Identifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Wildcard Characters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Using the WildcardFilter Preference Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Simulator Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Simulation Time Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Argument Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Command Shortcuts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Command History Shortcuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Numbering Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
VHDL Numbering Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Verilog Numbering Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
GUI_expression_format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Expression Typing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Expression Syntax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Signal and Subelement Naming Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Grouping and Precedence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Concatenation of Signals or Subelements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Record Field Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Searching for Binary Signal Values in the GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 2
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
abort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
add dataflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
add list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
add memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
add message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
add watch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
add wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
add_cmdhelp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
alias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

ModelSim Reference Manual, v10.1c 3

Table of Contents

archive load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
archive write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
batch_mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
bd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
bookmark add wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
bookmark delete wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
bookmark goto wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
bookmark list wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
bp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
call. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
cd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
classinfo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
configure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
dataset alias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
dataset clear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
dataset close . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
dataset config . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
dataset current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
dataset info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
dataset list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
dataset open. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
dataset rename. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
dataset restart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
dataset save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
dataset snapshot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
delete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
describe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
disablebp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
do. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
dumplog64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
edit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
enablebp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
examine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
exit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
find . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
find connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
find infiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
find insource . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
formatTime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

4 ModelSim Reference Manual, v10.1c

Table of Contents

lshift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
lsublist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
mem compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
mem display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
mem list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
mem load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
mem save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
mem search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
messages clearfilter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
messages setfilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
messages write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
modelsim. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
noforce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
nolog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
notepad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
noview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
nowhen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
onbreak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
onElabError. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
onerror. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
onfinish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
pause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
precision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
printenv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
process report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
pwd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
quietly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
quit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
radix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
radix define . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
radix delete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
radix list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
radix names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
radix signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
readers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
restart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
runStatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
searchlog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
see . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
setenv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
show . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
simstats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
stack down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
stack frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

ModelSim Reference Manual, v10.1c 5

Table of Contents

stack level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

stack tb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
stack up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
suppress. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
tb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
transcript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
transcript file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
transcript path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
transcript sizelimit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
tssi2mti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
ui_VVMode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
unsetenv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
vcd add . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
vcd checkpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
vcd comment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
vcd dumpports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
vcd dumpportsall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
vcd dumpportsflush. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
vcd dumpportslimit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
vcd dumpportsoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
vcd dumpportson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
vcd file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
vcd files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
vcd flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
vcd limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
vcd off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
vcd on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
vcd2wlf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
vcom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
vdel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
vdir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
vencrypt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
verror. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
vgencomp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
vhencrypt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
virtual count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
virtual define . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
virtual delete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
virtual describe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
virtual expand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
virtual function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
virtual hide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
virtual log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
virtual nohide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

6 ModelSim Reference Manual, v10.1c

Table of Contents

virtual nolog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316

virtual region. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
virtual save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
virtual show. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
virtual signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
virtual type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
vlib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
vlog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
vmake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
vmap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
vsim. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
vsim<info> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
vsim_break . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
vsource . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383
wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384
wave create . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
wave edit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394
wave export. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
wave import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
wave modify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400
wave sort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
when . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
where. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
wlf2log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
wlf2vcd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
wlfman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
wlfrecover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
write format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
write list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
write preferences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
write report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429
write timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
write transcript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
write tssi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435
write wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437
Index
End-User License Agreement

ModelSim Reference Manual, v10.1c 7

List of Examples

Example 1-1. SystemVerilog Scope Resolution Operator Example . . . . . . . . . . . . . . . . . . . 14

8 ModelSim Reference Manual, v10.1c

List of Figures

Figure 2-1. drivers Command Results in Transcript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

Figure 2-2. find infiles Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Figure 2-3. find insource Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Figure 2-4. readers Command Results in Transcript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

ModelSim Reference Manual, v10.1c 9

List of Tables

Table 1-1. Conventions for Command Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 1-2. Examples of Object Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Table 1-3. Wildcard Characters in HDL Object Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 1-4. WildcardFilter Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 1-5. WildcardFilter Argument Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 1-6. Keyboard Shortcuts for Command History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Table 1-7. VHDL Number Conventions: Style 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 1-8. VHDL Number Conventions: Style 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 1-9. Verilog Number Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 1-10. Constants Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 1-11. Array Constants Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . . . . 29
Table 1-12. Variables Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Table 1-13. Array Variables Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . . . . 30
Table 1-14. Operators Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 1-15. Precedence of GUI Expression Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Table 1-16. Casting Conversions Supported for GUI Expresssions . . . . . . . . . . . . . . . . . . . 33
Table 1-17. VHDL Logic Values Used in GUI Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Table 1-18. Verilog Logic Values Used in GUI Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Table 2-1. Supported Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Table 2-2. Message Viewer Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Table 2-3. runStatus Command States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Table 2-4. runStatus -full Command Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Table 2-5. Warning Message Categories for vcom -nowarn . . . . . . . . . . . . . . . . . . . . . . . . 284
Table 2-6. Design Unit Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Table 2-7. Warning Message Categories for vlog -nowarn . . . . . . . . . . . . . . . . . . . . . . . . . 339
Table 2-8. Wave Window Commands for Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384
Table 2-9. Wave Window Commands for Expanded Time Display . . . . . . . . . . . . . . . . . . 384
Table 2-10. Wave Window Commands for Controlling Display . . . . . . . . . . . . . . . . . . . . . 385
Table 2-11. Wave Window Commands for Zooming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

10 ModelSim Reference Manual, v10.1c

Chapter 1
Syntax and Conventions

Documentation Conventions
This manual uses the following conventions to define ModelSim command syntax.

Table 1-1. Conventions for Command Syntax

Syntax notation Description
< > angled brackets surrounding a syntax item indicate a
user-defined argument; do not enter the brackets in
commands
[ ] square brackets generally indicate an optional item; if
the brackets surround several words, all must be
entered as a group; the brackets are not entered1
{ } braces indicate that the enclosed expression contains
one or more spaces yet should be treated as a single
argument, or that the expression contains square
brackets for an index; for either situation, the braces
are entered
… an ellipsis indicates items that may appear more than
once; the ellipsis itself does not appear in commands
| the vertical bar indicates a choice between items on
either side of it; do not include the bar in the command
monospaced type monospaced type is used in command examples
# comments included with commands are preceded by
the number sign (#); useful for adding comments to
DO files (macros)
1. One exception to this rule is when you are using Verilog syntax to designate an array
slice. For example,

add wave {vector1[4:0]}

The square brackets in this case denote an index. The braces prevent the Tcl interpreter
from treating the text within the square brackets as a Tcl command.

Note
Neither the prompt at the beginning of a line nor the <Enter> key that ends a line is
shown in the command examples.

ModelSim Reference Manual, v10.1c 11

Syntax and Conventions
File and Directory Pathnames

File and Directory Pathnames

Several ModelSim commands have arguments that point to files or directories. For example, the
-y argument to vlog specifies the Verilog source library directory to search for undefined
modules. Spaces in file pathnames must be escaped or the entire path must be enclosed in
quotes. For example:

vlog top.v -y C:/Documents\ and\ Settings/projects/dut

or

vlog top.v -y "C:/Documents and Settings/projects/dut"

Design Object Names

Design objects are organized hierarchically. Each of the following objects creates a new level in
the hierarchy:

• VHDL — component instantiation statement, block statement, and package

• Verilog — module instantiation, named fork, named begin, task and function
• SystemVerilog — class, package, program, and interface

Object Name Syntax

The syntax for specifying object names in ModelSim is as follows:

[<dataset_name><datasetSeparator>][<pathSeparator>][<hierarchicalPath>]
<objectName>[<elementSelection>]

where

• dataset_name — is the name mapped to the WLF file in which the object exists. The
currently active simulation is the “sim” dataset. Any loaded WLF file is referred to by
the logical name specified when the WLF file was loaded. Refer to the chapter
“Recording Simulation Results With Datasets” in the User’s Manual for more
information.
• datasetSeparator — is the character used to terminate the dataset name. The default is
colon ( : ), though a different character (other than backslash ( \ )) may be specified as
the dataset separator via the DatasetSeparator variable in the modelsim.ini file. This
character must be different than the pathSeparator character.
• pathSeparator — is the character used to separate hierarchical object names. Normally,
a backslash ( \ ) is used for VHDL and a period ( . ) is used for Verilog, although other
characters (except a backslash ( \ )) may be specified via the PathSeparator variable in
the modelsim.ini file. This character must be different than the datasetSeparator. Neither

12 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Design Object Names

( . ) nor ( / ) can be used when referring to the contents of a SystemVerilog package or

class.
• hierarchicalPath — is a set of hierarchical instance names separated by a path
separator and ending in a path separator prior to the objectName. For example,
/top/proc/clk.
• objectName — is the name of an object in a design.
• elementSelection — indicates some combination of the following:
o Array indexing — Single array elements are specified using either parentheses ( () )
or square brackets ( [] ) around a single number. You must also surround the object
and specified array element with curly braces ( {} ). Refer to Tcl Syntax and
Specification of Array Bits and Slices for important information about using square
brackets and parentheses in ModelSim commands.
o Array slicing — Slices (or part-selects) of arrays are specified using either
parentheses ( () ) or square brackets ( [] ) around a range specification. A range is
two numbers separated by one of the following: " to ", " downto ", or a colon ( : ).
You must also surround the object and specified array slice with curly braces ( {} ).
Refer to Tcl Syntax and Specification of Array Bits and Slices for important
information about using square brackets and parentheses in ModelSim commands.
o Record field selection — A record field is specified using a period ( . ) followed by
the name of the field.

Tcl Syntax and Specification of Array Bits and Slices

Because ModelSim is a Tcl-based tool, you must surround objects and signals with curly braces
( {} ) when specifying array bits or slices with parentheses ( () ), spaces, or square brackets
( [] ). For example:

toggle add {data[3:0]}

toggle add {data(3 to 0)}
force {bus1[1]} 1

Further Details
Because ModelSim is basd on Tcl, its commands follow Tcl syntax. One problem you may
encounter with ModelSim commands is the use of square brackets ( [] ), parentheses ( () ), or
spaces when specifying array bits and slices. As shown on the previous page, square brackets
are used to specify slices of arrays (for example, data[3:0]). However, in Tcl, square brackets
signify command substitution. Consider the following example:

set aluinputs [find -in alu/*]

ModelSim Reference Manual, v10.1c 13

Syntax and Conventions
Design Object Names

ModelSim evaluates the find command first and then sets variable aluinputs to the result of the
find command. Obviously you don’t want this type of behavior when specifying an array slice,
so you would use curly brace escape characters:

add wave {/s/abc/data_in[10:1]}

You must also use the escape characters if using VHDL syntax with spaces:

add wave {/s/abc/data_in(10 downto 1)}

For complete details on Tcl syntax, refer to Tcl Command Syntax.

SystemVerilog Scope Resolution Operator

SystemVerilog offers the scope resolution operator, double colon ( :: ), for accessing classes
within a package and static data within a class. The example below shows various methods of
using this operator as well as alternatives using standard hierarchical references.

Example 1-1. SystemVerilog Scope Resolution Operator Example

package myPackage;
class packet;
static int a[0:1] = {1, 2};
int b[0:1];
int c;

function new;
b[0] = 3;
b[1] = 4;
c = a[0];
endfunction
endclass
endpackage : myPackage

module top;
myPackage::packet my = new;
int myint = my.a[1];
endmodule

The following examine examples access data from the class packet.

examine myPackage::packet::a
examine /top/my.a

Both of the above commands return the contents of the static array a within class packet.
examine myPackage::packet::a(0)
examine /top/my.a(0)

Both of the above commands return the contents of the first element of the static array a
within class packet.

14 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Design Object Names

examine /top/my.b

Return the contents of the instance-specific array b.

examine /top/my.b(0)

Return the contents of the first element of the instance-specific array b.

When referring to the contents of a package or class, you cannot use the standard path
separators, a period ( . ) or a forward slash ( / ).

Specifying Names
We distinguish between four "types" of object names: simple, relative, fully-rooted, and
absolute.

• Simple name — does not contain any hierarchy. It is simply the name of an object (e.g.,
clk or data[3:0]) in the current context.
• Relative name — does not start with a path separator and may or may not include a
dataset name or a hierarchical path (e.g., u1/data or view:clk). A relative name is relative
to the current context in the current or specified dataset.
• Fully-rooted name — starts with a path separator and includes a hierarchical path to an
object (e.g., /top/u1/clk).There is a special case of a fully-rooted name where the top-
level design unit name can be unspecified (e.g., /u1/clk). In this case, the first top-level
instance in the design is assumed.
• Absolute name — is an exactly specified hierarchical name containing a dataset name
and a fully rooted name (e.g., sim:/top/u1/clk).
The current dataset is used when accessing objects where a dataset name is not specified as part
of the name. The current dataset is determined by the dataset currently selected in the Structure
window or by the last dataset specified in an environment.

The current context in the current or specified dataset is used when accessing objects with
relative or simple names. The current context is either the current process, if any, or the current
instance if there is no current process, or the current process is not in the current instance. The
situation of the current process not being in the current instance can occur, for example, by
selecting a different instance in the Structure tab or by using the environment to set the current
context to a different instance.

The current context is also the activation level of an automatic task, function, or block. Different
levels of activation may be selected by using the Call Stack window, or by using the 'stack up'
or 'stack down' commands.

For example, when you set a breakpoint on line 5 of the following code:

package p;

ModelSim Reference Manual, v10.1c 15

Syntax and Conventions
Design Object Names

int I;
function automatic int factorial(int n);
if(n==0)
return 1;
else
return n * factorial(n - 1);
endfunction : factorial
endpackage : p
module top;
initial begin
p::I=p::factorial(3);

$display(p::I);
$display(p::factorial(4));
end
endmodule: top

When you issue the command:

examine n

the transcript returns:

However, when you issue the command:

stack up;examine n

the transcript returns:

Table 1-2 contains examples of various ways of specifying object names.

Table 1-2. Examples of Object Names

Object Name Description
clk specifies the object clk in the current context
/top/clk specifies the object clk in the top-level design unit.
/top/block1/u2/clk specifies the object clk, two levels down from the top-level
design unit
block1/u2/clk specifies the object clk, two levels down from the current
context
array_sig[4] specifies an index of an array object
{array_sig(1 to 10)} specifies a slice of an array object in VHDL; see Tcl
Syntax and Specification of Array Bits and Slices for more
information

16 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Wildcard Characters

Table 1-2. Examples of Object Names (cont.)

Object Name Description
{mysignal[31:0]} specifies a slice of an array object in Verilog; see Tcl
Syntax and Specification of Array Bits and Slices for more
information
record_sig.field specifies a field of a record

Environment Variables and Pathnames

You can substitute environment variables for pathnames in any argument that requires a
pathname. For example:

vlog -v $lib_path/und1

Assuming you have defined $lib_path on your system, vlog will locate the source library file
und1 and search it for undefined modules. Refer to Environment Variables for more
information.

Name Case Sensitivity

Name case sensitivity is different for VHDL and Verilog. VHDL names are not case sensitive
except for extended identifiers in VHDL 1076-1993 or later. In contrast, all Verilog names are
case sensitive.

Names in ModelSim commands are case sensitive when matched against case sensitive
identifiers, otherwise they are not case sensitive.

Extended Identifiers
The following are supported formats for extended identifiers for any command that takes an
identifier.

{\ext ident!\ }
# Note that trailing space before closing brace is required

\\ext\ ident\!\\
# All non-alpha characters escaped

Wildcard Characters
You can use wildcard characters in HDL object names for the following simulator commands:

• add dataflow
• add list

ModelSim Reference Manual, v10.1c 17

Syntax and Conventions
Wildcard Characters

• add memory
• add watch
• add wave
• find
• log
When you execute any of these commands with a wildcard, the default behavior is to exclude
the following object types:

• VHDL shared variables in packages and design units, constants, generics, and
immediate assertions
• Verilog parameters, specparams, memories
• PSL and SystemVerilog assertions, covers, and endpoints
• Signals in cells
You can alter these exclusions with the WildcardFilter preference variable. Refer to the section
“Using the WildcardFilter Preference Variable” for more information.

Table 1-3 identifies these supported wildcard characters.

Table 1-3. Wildcard Characters in HDL Object Names

Character Syntax Description
* matches any sequence of characters
? matches any single character
[] matches any one of the enclosed
characters; a hyphen can be used to
specify a range (for example, a-z, A-Z,
0-9); can be used only with the find
command

Note
A wildcard character does not match a path separator. For example, /dut/* will match
/dut/siga and /dut/clk. However, /dut* will not match either of those.

Using the WildcardFilter Preference Variable

The WildcardFilter preference variable controls which object types are excluded when
performing wildcard matches with simulator commands. The WildcardFilter preference
variable is a Tcl List and can be modified using Tcl commands. You can add both individual

18 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Wildcard Characters

(Figure 1-4) and group variables (Figure 1-5) to the current variable list, and you can remove
individual variables from the current list.

Note
Your WildcardFilter settings are persistent from one invocation to the next.

Procedure
Determining the Current WildcardFilter Variable Settings
Enter one of the following commands:

set WildcardFilter

or

echo $WildcardFilter

which returns the list of currently set variables.

Changing the WildcardFilter Settings from the Command Line

Refer to the list of WildcardFilter arguments in Table 1-4 and Figure 1-5 to determine what you
want to include in the wildcard matches.

• To define a new list of values enter the following command:

set WildcardFilter “<arg1 arg2 ...>”

Note that you must enclose the space-separated list of arguments in quotation marks.
• To add one or more values to the current list enter the following command:
lappend WildcardFilter <arg1 arg2 ...>

Note that you must not enclose the space-separated list of arguments in quotation marks.
• To remove a value from the filter use the set command with the Tcl lsearch command to
create the new list from the existing list. For example:
set WildcardFilter [lsearch -not -all -inline $WildcardFilter Endpoint]
Changing the WildcardFilter Settings back to the Default
Enter the following command:

set WildcardFilter default

Changing the WildcardFilter settings from the GUI

1. Choose Tools > Wildcard Filter from the main menu.

ModelSim Reference Manual, v10.1c 19

Syntax and Conventions
Wildcard Characters

2. Select the individual Filters you want to exclude from wildcard searches (Table 1-4
describes each option), or select Composite Filters to activate related filters (Table 1-5
describes each composite option).
3. Click OK.
Refer to the Tcl man pages (Help>Tcl Man Pages) for more information about the lsearch and
set commands.

WildcardFilter Argument Descriptions

Table 1-4 provides a list of the WildcardFilter arguments.

Table 1-4. WildcardFilter Arguments

Argument Description
Alias VHDL Alias
Assertion Concurrent SystemVerilog or PSL assertion
CellInternal Signals in cells, where a cell is defined as 1) a module within a
‘celldefine 2) a Verilog module found with a library search
(using either vlog -v or vlog -y) and compiled with vlog +libcell
or 3) a module containing a specify block
Class Verilog class declaration
ClassReference SystemVerilog class reference
Compare Waveform comparison signal
Constant VHDL constant
Cover SystemVerilog or PSL cover statements
Covergroup SystemVerilog or PSL covergroup
Coverpoint Verilog coverpoint
Cross Verilog cross
Endpoint SystemVerilog assertion objects created for sequences on which
the method “ended/triggered” is used.
PSL assertion objects created for sequences for which the built
in function “ended()” is used.
Generic VHDL generic
ImmediateAssert VHDL immediate assertions
Integer VHDL integer
Memory Verilog memories
NamedEvent Verilog named event
Net Verilog net

20 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Wildcard Characters

Table 1-4. WildcardFilter Arguments (cont.)

Argument Description
Parameter Verilog parameter
Real Verilog real registers
Reg Verilog register
ScVariable SystemC variable
Signal VHDL signal
SpecParam Verilog specparam
Time Verilog time registers
Transaction Transaction stream and stream arrays
Variable VHDL shared variables in packages and design units.
VirtualExpr Virtual expression
VirtualSignal Virtual signal
Table 1-5 provides a list of the group aliases of WildcardFilter arguments. You can set a group
value with the set command. The expanded list of values is returned.

Table 1-5. WildcardFilter Argument Groups

Group Argument Specific arguments included
AllVHDL Signal, Variable, Constant, Generic, Alias
AllVerilogVars Parameter, Reg, Integer, Time, Real, SpecParam, Memory,
NamedEvent, ClassReference
AllVerilog Net, Parameter, Reg, Integer, Time, Real, SpecParam,
Memory, NamedEvent, Class, Cross, Covergroup,
Coverpoint, ClassReference
VirtualSignals VirtualSignal, VirtualExpr
SystemC ScVariable
AllHDLSignals Signal, Variable, Constant, Generic, Alias, Net, Parameter,
Reg, Integer, Time, Real, SpecParam, Memory,
NamedEvent, VirtualSignal, VirtualExpr, ClassReference
AllVariables Variable, Constant, Generic, Alias, Parameter, Reg,
Integer, Time, Real, SpecParam, Memory, NamedEvent,
ClassReference
AllHDLSignalsVars Signal, Variable, Constant, Generic, Alias, Net, Parameter,
Reg, Integer, Time, Real, SpecParam, Memory,
NamedEvent, VirtualSignal, VirtualExpr, ClassReference

ModelSim Reference Manual, v10.1c 21

Syntax and Conventions
Simulator Variables

Table 1-5. WildcardFilter Argument Groups (cont.)

Group Argument Specific arguments included
AllSignals Signal, Net, Parameter, Reg, Integer, Time, Real,
SpecParam, Memory, NamedEvent, VirtualSignal,
VirtualExpr, Endpoint, ClassReference
AllSignalsVars Signal, Variable, Constant, Generic, Alias, Net, Parameter,
Reg, Integer, Time, Real, SpecParam, Memory,
NamedEvent, VirtualSignal, VirtualExpr, Endpoint,
ScVariable, ClassReference
AllConstants Constant, Generic, Parameter, SpecParam
Default Variable, Constant, Generic, Parameter, SpecParam,
Memory, Assertion, Cover, Endpoint, ScVariable,
CellInternal, ImmediateAssert

Simulator Variables
You can reference ModelSim variables in a simulator command by preceding the name of the
variable with the dollar sign ($) character. ModelSim uses global variables for simulator state
variables, simulator control variables, simulator preference variables, and user-defined
variables. Refer to modelsim.ini Variables in the User’s Manual for more information on
variables.

The report command returns a list of current settings for either the simulator state or simulator
control variables.

Simulation Time Units

You can specify the time unit for delays in all simulator commands that have time arguments.
For example:

force clk 1 50 ns, 1 100 ns -repeat 1 us

run 2 ms

Note that all the time units in a ModelSim command need not be the same.

Unless you specify otherwise as in the examples above, simulation time is always expressed
using the resolution units that are specified by the UserTimeUnit variable.

By default, the specified time units are assumed to be relative to the current time unless the
value is preceded by the character @, which signifies an absolute time specification.

22 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Argument Files

Argument Files
You can load additional arguments into some commands by using argument files, which are
specified with the -f argument. The following commands support the -f argument:

vlog vcom vencrypt vmake vsim

The -f <filename> argument specifies a file that contains additional command line arguments.
The following sections outline some syntax rules for argument files.

• Single Quotes ( ‘ ‘ )— Allows you to group arbitrary characters so that no character

substitution occurs within the quotes, such as environment variable expansion or
escaped characters.
+acc=rn+'\mymodule’
//does not treat the ‘\’ as an escape character

• Double Quotes ( “ “ )— Allows you to group arbitrary characters so that Tcl-style

backslash substitution and environment variable expansion is performed.
+acc=rn+"\\mymodule\\$VAR"
// escapes the path separators (\) and substitues
// your value of ‘$VAR’

• Unquoted — The following are notes on what occurs when some information is not
quoted:
o Tcl backslash substitution — Any unquoted backslash ( \ ) will be treated as an
escape character.
+acc=rn\\mymodule
// the leading '\' is considered an escape character

o Environment variable expansion — Any unquoted environment variable, such as

$envname, will be expanded. You can also use curly braces ( { } ) in your
environment variable, such as ${envname}.
+acc=rn\\$MODULE
// the leading '\' is considered an escape character and the
// variable $MODULE is expanded

• Newline Character — You can specify arguments on separate lines in the argument file
with the line continuation character ( \ ). You must use a space before the backslash.
• Comments — Comments within the argument files follow these rules:
o All text in a line beginning with // to its end is treated as a comment.
o All text bracketed by /* … */ is treated as a comment.
o All text in a line beginning with # to its end is treated as a comment.

ModelSim Reference Manual, v10.1c 23

Syntax and Conventions
Command Shortcuts

Command Shortcuts
• You may abbreviate command syntax, but there’s a catch — the minimum number of
characters required to execute a command are those that make it unique. Remember, as
we add new commands some of the old shortcuts may not work. For this reason
ModelSim does not allow command name abbreviations in macro files. This minimizes
your need to update macro files as new commands are added.
• Multiple commands may be entered on one line if they are separated by semi-colons (;).
For example:
ModelSim> vlog -nodebug=ports level3.v level2.v ; vlog -nodebug top.v

The return value of the last function executed is the only one printed to the transcript.
This may cause some unexpected behavior in certain circumstances. Consider this
example:
vsim -c -do "run 20 ; simstats ; quit -f" top

You probably expect the simstats results to display in the Transcript window, but they
will not, because the last command is quit -f. To see the return values of intermediate
commands, you must explicitly print the results. For example:
vsim -do "run 20 ; echo [simstats]; quit -f" -c top

Command History Shortcuts

You can review simulator command history or rerun previous commands by using keyboard
shortcuts at the ModelSim/VSIM prompt. Table 1-6 contains a list of these shortcuts.

Table 1-6. Keyboard Shortcuts for Command History

Shortcut Description
!! repeats the last command
!n repeats command number n; n is the VSIM prompt
number (e.g., for this prompt: VSIM 12>, n =12)
!<string> shows a list of executed commands that start with
<string>. Use the up and down arrows to choose from
the list.
!abc repeats the most recent command starting with "abc"
^xyz^ab^ replaces "xyz" in the last command with "ab"
up and down arrows scrolls through the command history with the keyboard
arrows
click on prompt left-click once on a previous ModelSim or VSIM
prompt in the transcript to copy the command typed at
that prompt to the active cursor

24 ModelSim Reference Manual, v10.1c

Syntax and Conventions
Numbering Conventions

Table 1-6. Keyboard Shortcuts for Command History (cont.)

Shortcut Description
his or history shows the last few commands (up to 50 are kept)

Numbering Conventions
Numbers in ModelSim can be expressed in either VHDL or Verilog style. You can use two
styles for VHDL numbers and one for Verilog.

VHDL Numbering Conventions

There are two types of VHDL number styles:

VHDL Style 1
[ - ] [ radix # ] value [ # ]

Table 1-7. VHDL Number Conventions: Style 1

Element Description
- indicates a negative number; optional
radix can be any base in the range 2 through 16 (2, 8, 10, or 16); by default,
numbers are assumed to be decimal; optional
value specifies the numeric value, expressed in the specified radix; required
# is a delimiter between the radix and the value; the first # sign is required
if a radix is used, the second is always optional
A ‘-’ can also be used to designate a "don’t care" element when you search for a signal value or
expression in the List or Wave window. If you want the ‘-’ to be read as a "don’t care" element,
rather than a negative sign, be sure to enclose the number in double quotes. For instance, you
would type "-0110--" as opposed to -0110--. If you don’t include the double quotes, ModelSim
will read the ‘-’ as a negative sign. For example:

16#FFca23#
2#11111110
-23749

VHDL Style 2
base "value"

Table 1-8. VHDL Number Conventions: Style 2

Element Description
base specifies the base; binary: B, octal: O, hex: X; required

ModelSim Reference Manual, v10.1c 25

Syntax and Conventions
Numbering Conventions

Table 1-8. VHDL Number Conventions: Style 2 (cont.)

Element Description
"value" specifies digits in the appropriate base with optional underscore
separators; default is decimal; required
For example:

B"11111110"
X"FFca23"

Searching for VHDL Arrays in the Wave and List Windows

Searching for signal values in the Wave or List window may not work correctly for VHDL
arrays if the target value is in decimal notation. You may get an error that the value is of
incompatible type. Since VHDL does not have a radix indicator for decimal, the target value
may get misinterpreted as a scalar value. Prefixing the value with the Verilog notation 'd should
eliminate the problem, even if the signal is VHDL.

Verilog Numbering Conventions

Verilog numbers are expressed in the style:

[ - ] [ size ] [ base ] value

Table 1-9. Verilog Number Conventions

Element Description
- indicates a negative number; optional
size the number of bits in the number; optional
base specifies the base; binary: ‘b or ‘B, octal: ‘o or ‘O, decimal: ‘d or ‘D, hex: ‘h
or ‘H; optional
value specifies digits in the appropriate base with optional underscore separators;
default is decimal; required
A ‘-’ can also be used to designate a "don’t care" element when you search for a signal value or
expression in the List or Wave windows. If you want the ‘-’ to be read as a "don’t care" element,
rather than a negative sign, be sure to enclose the number in double quotes. For instance, you
would type "-0110--" as opposed to 7'b-0110--. If you don’t include the double quotes,
ModelSim will read the ‘-’ as a negative sign. For example:

’b11111110 8’b11111110
’Hffca23 21’H1fca23
-23749

26 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

GUI_expression_format
The GUI_expression_format is an option of several simulator commands that operate within the
ModelSim GUI environment. The expressions help you locate and examine objects within the
List and Wave windows (expressions may also be used through the Edit > Search menu in both
windows). The commands that use the expression format are:

configure, examine, searchlog, virtual function, virtual signal.

Expression Typing
GUI expressions are typed. The supported types consist of the following scalar and array types.

Scalar Types
The scalar types are as follows: boolean, integer, real, time (64-bit integer), enumeration, and
signal state. Signal states are represented by the nine VHDL std_logic states: ’U’ ’X’ ’0’ ’1’ ’Z’
’W’ ’L’ ’H’ and ’-’.

Verilog states 0, 1, x, and z are mapped into these states and the Verilog strengths are ignored.
Conversion is done automatically when referencing Verilog nets or registers.

Array Types
The supported array types are signed and unsigned arrays of signal states. This would
correspond to the VHDL std_logic_array type. Verilog registers are automatically converted to
these array types. The array type can be treated as either UNSIGNED or SIGNED, as in the
IEEE std_logic_arith package. Normally, referencing a signal array causes it to be treated as
UNSIGNED by the expression evaluator; to cause it to be treated as SIGNED, use casting as
described below. Numeric operations supported on arrays are performed by the expression
evaluator via ModelSim’s built-in numeric_standard (and similar) package routines. The
expression evaluator selects the appropriate numeric routine based on SIGNED or UNSIGNED
properties of the array arguments and the result.

The enumeration types supported are any VHDL enumerated type. Enumeration literals may be
used in the expression as long as some variable of that enumeration type is referenced in the
expression. This is useful for sub-expressions of the form:

(/memory/state == reading)

Expression Syntax
GUI expressions generally follow C-language syntax, with both VHDL-specific and Verilog-
specific conventions supported. These expressions are not parsed by the Tcl parser, and so do

ModelSim Reference Manual, v10.1c 27

Syntax and Conventions
GUI_expression_format

not support general Tcl; parentheses should be used rather than braces. Procedure calls are not
supported.

A GUI expression can include the following elements: Tcl macros, constants, array constants,
variables, array variables, signal attributes, operators, and casting.

Tcl Macros
Macros are useful for pre-defined constants or for entire expressions that have been previously
saved. The substitution is done only once, when the expression is first parsed. Macro syntax is:

$<name>

Substitutes the string value of the Tcl global variable <name>.

28 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

Constants
Table 1-10. Constants Supported for GUI Expresssions
Type Values
boolean value true false TRUE FALSE
integer [0-9]+
real number <int>|([<int>].<int>[exp]) where the optional [exp] is: (e|E)[+|-][0-
9]+
time integer or real optionally followed by time unit
enumeration VHDL user-defined enumeration literal
single bit constants expressed as any of the following:
0 1 x X z Z U H L W ’U’ ’X’ ’0’ ’1’ ’Z’ ’W’ ’L’ ’H’ ’-’ 1’b0 1’b1

Array Constants, Expressed in Any of the Following Formats

Table 1-11. Array Constants Supported for GUI Expresssions
Type Values
VHDL # notation <int>#<alphanum>[#]
Example: 16#abc123#
VHDL bitstring "(U|X|0|1|Z|W|L|H|-)*"
Example: "11010X11"
Verilog notation [-][<int>]’(b|B|o|O|d|D|h|H) <alphanum>
(where <alphanum> includes 0-9, a-f, A-F, and ’-’)
Example: 12’hc91 (This is the preferred notation because it removes the
ambiguity about the number of bits.)
Based notation 0x…, 0X…, 0o…, 0O…, 0b…, OB…
ModelSim automatically zero fills unspecified upper bits.

Variables
Table 1-12. Variables Supported for GUI Expresssions
Variable Type
Name of a signal The name may be a simple name, a VHDL or Verilog style extended
identifier, or a VHDL or Verilog style path. The signal must be one of
the following types:
-- VHDL signal of type INTEGER, REAL, or TIME
-- VHDL signal of type std_logic or bit
-- VHDL signal of type user-defined enumeration
-- Verilog net, Verilog register, Verilog integer, or Verilog real

ModelSim Reference Manual, v10.1c 29

Syntax and Conventions
GUI_expression_format

Table 1-12. Variables Supported for GUI Expresssions (cont.)

Variable Type
NOW Returns the value of time at the current location in the WLF file as the
WLF file is being scanned (not the most recent simulation time).

Array variables
Table 1-13. Array Variables Supported for GUI Expresssions
Variable Type
Name of a signal -- VHDL signals of type bit_vector or std_logic_vector
-- Verilog register
-- Verilog net array
A subrange or index may be specified in either VHDL or Verilog
syntax. Examples: mysignal(1 to 5), mysignal[1:5], mysignal (4),
mysignal [4]

Signal attributes
<name>’event
<name>’rising
<name>’falling
<name>’delayed()
<name>’hasX

The ’delayed attribute lets you assign a delay to a VHDL signal. To assign a delay to a signal in
Verilog, use “#” notation in a sub-expression (e.g., #-10 /top/signalA).

The hasX attribute lets you search for signals, nets, or registers that contains an X (unknown)
value.

See Examples of Expression Syntax below for further details on ’delayed and ’hasX.

30 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

Operators
Table 1-14. Operators Supported for GUI Expresssions
Operator Description Kind
+ arithmetic add arithmetic
/ arithmetic divide arithmetic
mod/MOD arithmetic modulus arithmetic
* arithmetic multiply arithmetic
rem/REM arithmetic remainder arithmetic
- arithmetic subtract arithmetic
& concat arithmetic
<name>'delayed(<time>) delayed signal (<time>) attributes
<name>'falling Falling edge attributes
<name>'rising Rising edge attributes
<name>'event Value change attributes
<name>'hasX Value has an X attributes
and, AND bitwise and bitwise logical
nand, NAND bitwise nand bitwise logical
nor, NOR bitwise nor bitwise logical
or, OR bitwise or bitwise logical
xnor, XNOR bitwise xnor bitwise logical
xor, XOR bitwise xor bitwise logical
rol, ROL rotate left bitwise logical
ror, ROR rotate right bitwise logical
sla, SLA shift left arithmetic bitwise logical
sll, SLL shift left logical bitwise logical
sra, SRA shift right arithmetic bitwise logical
srl, SRL shift right logical bitwise logical
not, NOT, ~ unary bitwise inversion bitwise logical
&& boolean and boolean
! boolean not boolean
|| boolean or boolean

ModelSim Reference Manual, v10.1c 31

Syntax and Conventions
GUI_expression_format

Table 1-14. Operators Supported for GUI Expresssions (cont.)

Operator Description Kind
== equal boolean
=== exact equal1 boolean
!== exact not equal1 boolean
> greater than boolean
>= greater than or equal boolean
< less than boolean
<= less than or equal boolean
!=, /= not equal boolean
&<vector_expr> AND reduction reduction
|<vector_expr> OR reduction reduction
^<vector_expr> XOR reduction reduction
1. This operator is allowed to be compatible with other simulators.

Table 1-15. Precedence of GUI Expression Operators

Operator Kind
delayed(), 'falling, 'rising, 'event, 'hasX attributes
&, |, ^ unary
!, not, NOT, ~ boolean
/, mod, MOD, *, rem, REM arithmetic
nand, NAND, nor, NOR bitwise logical
and, AND bitwise logical
xor, XOR, xnor, XNOR bitwise logical
or, OR bitwise logical
+, - arithmetic
& concat
rol, ROL, ror, ROR, sla, SLA, sll, SLL, sra, SRA, srl, SRL bitwise logical
>, >=, <, <= boolean
==, ===, !==, !=, /= boolean
&& boolean

32 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

Table 1-15. Precedence of GUI Expression Operators (cont.)

Operator Kind
|| boolean

Note
Arithmetic operators use the std_logic_arith package.

Casting
Table 1-16. Casting Conversions Supported for GUI Expresssions
Casting Description
(bool) convert to boolean
(boolean) convert to boolean
(int) convert to integer
(integer) convert to integer
(real) convert to real
(time) convert to 64-bit integer
(std_logic) convert to 9-state signal value
(signed) convert to signed vector
(unsigned) convert to unsigned vector
(std_logic_vector) convert to unsigned vector

Examples of Expression Syntax

/top/bus & $bit_mask

This expression takes the bitwise AND function of signal /top/bus and the array constant
contained in the global Tcl variable bit_mask.
clk’event && (/top/xyz == 16’hffae)

This expression evaluates to a boolean true when signal clk changes and signal /top/xyz
is equal to hex ffae; otherwise is false.
clk’rising && (mystate == reading) && (/top/u3/addr == 32’habcd1234)

Evaluates to a boolean true when signal clk just changed from low to high and signal
mystate is the enumeration reading and signal /top/u3/addr is equal to the specified
32-bit hex constant; otherwise is false.

ModelSim Reference Manual, v10.1c 33

Syntax and Conventions
GUI_expression_format

(/top/u3/addr and 32’hff000000) == 32’hac000000

Evaluates to a boolean true when the upper 8 bits of the 32-bit signal /top/u3/addr equals
hex ac.
/top/signalA'delayed(10ns)

This expression returns /top/signalA delayed by 10 ns.

/top/signalA'delayed(10 ns) && /top/signalB

This expression takes the logical AND of a delayed /top/signalA with /top/signalB.
virtual function { (#-10 /top/signalA) && /top/signalB}
mySignalB_AND_DelayedSignalA

This evaluates /top/signalA at 10 simulation time steps before the current time, and takes
the logical AND of the result with the current value of /top/signalB. The '#' notation uses
positive numbers for looking into the future, and negative numbers for delay. This
notation does not support the use of time units.
((NOW > 23 us) && (NOW < 54 us)) && clk’rising && (mode == writing)

Evaluates to a boolean true when WLF file time is between 23 and 54 microseconds, clk
just changed from low to high, and signal mode is enumeration writing.
searchlog -expr {dbus'hasX} {0 ns} dbus

Searches for an ’X’ in dbus. This is equivalent to the expression: {dbus(0) == 'x' ||
dbus(1) == 'x'} . . .. This makes it possible to search for X values without having to
write a type specific literal.

Signal and Subelement Naming Conventions

ModelSim supports naming conventions for VHDL and Verilog signal pathnames, VHDL array
indexing, Verilog bit selection, VHDL subrange specification, and Verilog part selection.

Examples in Verilog and VHDL syntax:

top.chip.vlogsig
/top/chip/vhdlsig
vlogsig[3]
vhdlsig(9)
vlogsig[5:2]
vhdlsig(5 downto 2)

Grouping and Precedence

Operator precedence generally follows that of the C language, but we recommend liberal use of
parentheses.

34 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

Concatenation of Signals or Subelements

Elements in the concatenation that are arrays are expanded so that each element in the array
becomes a top-level element of the concatenation. But for elements in the concatenation that are
records, the entire record becomes one top-level element in the result. To specify that the
records be broken down so that their subelements become top-level elements in the
concatenation, use the concat_flatten directive. Currently we do not support leaving full arrays
as elements in the result. (Please let us know if you need that option.)

If the elements being concatenated are of incompatible base types, a VHDL-style record will be
created. The record object can be expanded in the Objects and Wave windows just like an array
of compatible type elements.

Concatenation Syntax for VHDL

<signalOrSliceName1> & <signalOrSliceName2> & ...

Concatenation Syntax for Verilog

&{<signalOrSliceName1>, <signalOrSliceName2>, ... }
&{<count>{<signalOrSliceName1>}, <signalOrSliceName2>, ... }

Note that the concatenation syntax begins with "&{" rather than just "{". Repetition multipliers
are supported, as illustrated in the second line. The repetition element itself may be an arbitrary
concatenation subexpression.

Concatenation Directives
A concatenation directive (as illustrated below) can be used to constrain the resulting array
range of a concatenation or influence how compound objects are treated. By default, the
concatenation will be created with a descending index range from (n-1) down to 0, where n is
the number of elements in the array.

(concat_range 31:0)<concatenationExpr> # Verilog syntax

(concat_range (31:0))<concatenationExpr> # Also Verilog syntax
(concat_range (31 downto 0))<concatenationExpr> # VHDL syntax

The concat_range directive completely specifies the index range.

(concat_ascending) <concatenationExpr>

The concat_ascending directive specifies that the index start at zero and increment
upwards.
(concat_flatten) <concatenationExpr>

The concat_flatten directive flattens the signal structure hierarchy.

(concat_noflatten) <concatenationExpr>

ModelSim Reference Manual, v10.1c 35

Syntax and Conventions
GUI_expression_format

The concat_noflatten directive groups signals together without merging them into one
big array. The signals become elements of a record and retain their original names.
When expanded, the new signal looks just like a group of signals. The directive can be
used hierarchically with no limits on depth.
(concat_sort_wild_ascending) <concatenationExpr>

The concat_sort_wild_ascending directive gathers signals by name in ascending order

(the default is descending).
(concat_reverse) <concatenationExpr>

The concat_reverse directive reverses the bits of the concatenated signals.

Examples of Concatenation
&{ "mybusbasename*" }

Gathers all signals in the current context whose names begin with "mybusbasename",
sorts those names in descending order, and creates a bus with index range (n-1) downto
0, where n is the number of matching signals found. (Note that it currently does not
derive the index name from the tail of the one-bit signal name.)
(concat_range 13:4)&{ "mybusbasename*" }

Specifies the index range to be 13 downto 4, with the signals gathered by name in
descending order.
(concat_ascending)&{ "mybusbasename*" }

Specifies an ascending range of 0 to n-1, with the signals gathered by name in

descending order.
(concat_ascending)((concat_sort_wild_ascending)&{"mybusbasename*" })

Specifies an ascending range of 0 to n-1, with the signals gathered by name in ascending
order.
(concat_reverse)(bus1 & bus2)

Specifies that the bits of bus1 and bus2 be reversed in the output virtual signal.

Record Field Members

Arbitrarily-nested arrays and records are supported, but operators will only operate on one field
at a time. That is, the expression {a == b} where a and b are records with multiple fields, is not
supported. This would have to be expressed as:

{(a.f1 == b.f1) && (a.f2 == b.f2) ...}

Examples:

36 ModelSim Reference Manual, v10.1c

Syntax and Conventions
GUI_expression_format

vhdlsig.field1
vhdlsig.field1.subfield1
vhdlsig.(5).field3
vhdlsig.field4(3 downto 0)

Searching for Binary Signal Values in the GUI

When you use the GUI to search for signal values displayed in 4-state binary radix, you should
be aware of how ModelSim maps between binary radix and std_logic. The issue arises because
there is no “un-initialized” value in binary, while there is in std_logic. So, ModelSim relies on
mapping tables to determine whether a match occurs between the displayed binary signal value
and the underlying std_logic value.

This matching algorithm applies only to searching using the GUI. It does not apply to VHDL or
Verilog test benches.

For comparing VHDL std_logic/std_ulogic objects, ModelSim uses the table shown below. An
entry of “0” in the table is “no match”; an entry of “1” is a “match”; an entry of “2” is a match
only if you set the Tcl variable STDLOGIC_X_MatchesAnything to 1. Note that X will match
a U, and - will match anything.

Table 1-17. VHDL Logic Values Used in GUI Search

Search Matches as follows:
Entry
U X 0 1 Z W L H -
U 1 1 0 0 0 0 0 0 1
X 1 1 2 2 2 2 2 2 1
0 0 2 1 0 0 0 1 0 1
1 0 2 0 1 0 0 0 1 1
Z 0 2 0 0 1 0 0 0 1
W 0 2 0 0 0 1 0 0 1
L 0 2 1 0 0 0 1 0 1
H 0 2 0 1 0 0 0 1 1
- 1 1 1 1 1 1 1 1 1

ModelSim Reference Manual, v10.1c 37

Syntax and Conventions
GUI_expression_format

For comparing Verilog net values, ModelSim uses the table shown below. An entry of “2” is a
match only if you set the Tcl variable “VLOG_X_MatchesAnything” to 1.

Table 1-18. Verilog Logic Values Used in GUI Search

Search Matches as follows:
Entry
0 1 Z X
0 1 0 0 2
1 0 1 0 2
Z 0 0 1 2
X 2 2 2 1

38 ModelSim Reference Manual, v10.1c

Chapter 2
Commands

This chapter describes ModelSim commands that you can enter either on the command line of
the Main window or in a macro file. Some commands are automatically entered on the
command line when you use the graphical user interface.
Note that, in addition to the simulation commands listed in this chapter, you can also use the Tcl
commands described in the Tcl man pages (use the Main window menu selection: Help > Tcl
Man Pages).
Table 2-1 provides a brief description of each ModelSim command. For more information on
command details, arguments, and examples, click the link in the Command name column.

Table 2-1. Supported Commands

Command name Action
abort halts the execution of a macro file interrupted by a breakpoint or
error
add dataflow adds the specified object(s) to the Dataflow window
add list lists VHDL signals and variables, and Verilog nets and registers,
and their values in the List window
add log also known as the log command; see log
add memory opens the specified memory in the MDI frame of the Main
window
add message used within a macro or script and specifies a user defined runtime
message that is sent to the transcript and .wlf files.
add watch adds signals or variables to the Watch window
add wave adds VHDL signals and variables, and Verilog nets and registers
to the Wave window
add_cmdhelp adds an entry to the command-line help; use the help command to
display the help text
alias creates a new Tcl procedure that evaluates the specified
commands
archive load allows you to load an archived debug database (.dbg) file that was
previously created with the archive write command

ModelSim Reference Manual, v10.1c 39

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
archive write allows you to create a debug archive file, with the file extension
.dgb, that contains one or more WLF files, debug information
captured from the design library, an optional connectivity debug
database file, and optional HDL source files.
batch_mode returns a 1 if ModelSim is operating in batch mode, otherwise
returns a 0
bd deletes a breakpoint
bookmark add wave adds a bookmark to the specified Wave window
bookmark delete wave deletes bookmarks from the specified Wave window
bookmark goto wave zooms and scrolls a Wave window using the specified bookmark
bookmark list wave displays a list of available bookmarks
bp sets a breakpoint
call calls SystemVerilog static, package, and class functions
change modifies the value of a VHDL variable or Verilog register
variable
classinfo displays information about class types and instances
configure invokes the List or Wave widget configure command for the
current default List or Wave window
dataset alias assigns an additional name to a dataset
dataset clear clears the current simulation WLF file
dataset close closes a dataset
dataset config configures WLF file settings after dataset is open
dataset current opens the specified dataset and sets the GUI context to the last
selected context of the specified dataset.
dataset info reports information about the specified dataset
dataset list lists the open dataset(s)
dataset open opens a dataset and references it by a logical name
dataset rename changes the logical name of an opened dataset
dataset restart unloads specified or current dataset
dataset save saves data from the current WLF file to a specified file
dataset snapshot saves data from the current WLF file at a specified interval
delete removes objects from either the List or Wave window

40 ModelSim Reference Manual, v10.1c

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
describe displays information about the specified HDL object
disablebp turns off breakpoints and when commands
do executes commands contained in a macro file
drivers displays in the Main window the current value and scheduled
future values for all the drivers of a specified VHDL signal or
Verilog net
dumplog64 dumps the contents of the vsim.wlf file in a readable format
echo displays a specified message in the Main window
edit invokes the editor specified by the EDITOR environment variable
enablebp turns on breakpoints and when commands turned off by the
disablebp command
encoding translates between Unicode Tcl strings and a named encoding
environment displays or changes the current dataset and region environment
examine examines one or more objects, and displays current values (or the
values at a specified previous time) in the Main window
exit exits the simulator and the ModelSim application
find displays the full pathnames of all objects in the design whose
names match the name specification you provide
find infiles searches the specified files and prints to the Transcript window
those lines from the files that match the specified pattern.
find insource searches all source files related to the current design and prints to
the Transcript window those lines from the files that match the
specified pattern.
force applies stimulus to VHDL signals and Verilog nets
formatTime global format control for all time values displayed in the GUI
help displays in the Main window a brief description and syntax for the
specified command
history lists the commands executed during the current session
layout allows you to perform operations on GUI layouts
log creates a wave log format (WLF) file containing simulation data
for all objects whose names match the provided specifications
lshift takes a Tcl list as an argument and shifts it in-place one place to
the left, eliminating the left-most element

ModelSim Reference Manual, v10.1c 41

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
lsublist returns a sublist of the specified Tcl list that matches the specified
Tcl glob pattern
mem compare compares the selected memory to a reference memory or file
mem display displays the memory contents of a selected instance to the screen
mem list displays a flattened list of all memory instances in the current or
specified context after a design has been elaborated
mem load updates the simulation memory contents of a specified instance
mem save saves the contents of a memory instance to a file in any of the
supported formats: Verilog binary, Verilog hex, and MTI memory
pattern data
mem search finds and prints to the screen the first occurring match of a
specified memory pattern in the specified memory instance
messages clearfilter removes any filter you have set in the Message Viewer
messages setfilter performs the same action as the Message Viewer Filter Dialog
Box, lets you determine which messages are shown in the
Message Viewer
messages write prints the contents of the Message Viewer window to a specified
text file.
modelsim starts the ModelSim GUI without prompting you to load a design;
valid only for Windows platforms
noforce removes the effect of any active force commands on the selected
object
nolog suspends writing of data to the WLF file for the specified signals
notepad opens a simple text editor
noview closes a window or set of windows in the ModelSim GUI
nowhen deactivates selected when commands
onbreak specifies command(s) to be executed when running a macro that
encounters a breakpoint in the source code; in effect only during a
run command
onElabError specifies one or more commands to be executed when an error is
encountered during elaboration; in effect only during a vsim
command
onerror specifies one or more commands to be executed when a Tcl
command in a dofile encounters an error; not dependent on a run
command

42 ModelSim Reference Manual, v10.1c

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
onfinish controls simulator behavior when encountering $finish or
sc_stop() in the design code
pause interrupts the execution of a macro
precision determines how real numbers display in the GUI
printenv echoes to the Main window the current names and values of all
environment variables
process report creates textual report of all processes displayed in the Process
window
project performs common operations on new projects
pwd displays the current directory path in the Main window
quietly turns off transcript echoing for the specified command
quit exits the simulator
radix specifies the default radix to be used
radix define creates or modifies a user-defined radix
radix delete removes the radix definition from the named radix
radix list returns the complete definition of a radix
radix names returns a list of currently defined radix names
radix signal sets or inspects radix values for the specified signal in the Objects,
Locals, and Wave windows
report displays the value of all simulator control variables, or the value
of any simulator state variables relevant to the current simulation
restart reloads the current dataset if the current dataset is not the active
simulation ("sim") and resets the simulation time to zero, in effect
acting just like a restart of a simulation
resume continues execution of a macro file after a pause command or a
breakpoint
run advances the simulation by the specified number of timesteps
runStatus returns the current state of your simulation after issuing a run or
step command
searchlog searches one or more of the currently open logfiles for a specified
condition
see displays the specified number of source file lines around the
current execution line

ModelSim Reference Manual, v10.1c 43

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
setenv sets an environment variable
shift shifts macro parameter values down one place
show lists objects and subregions visible from the current environment
simstats reports performance-related statistics about active simulations
stack down moves down the call stack
stack frame selects the specified call frame
stack level reports the current call frame number
stack tb is an alias for the tb command
stack up moves up the call stack
status lists all currently interrupted macros
step steps to the next HDL statement
stop stops simulation in batch files; used with the when command
suppress prevents the specified message(s) from displaying
tb displays a stack trace for the current process in the Transcript
window
Time performs various numerical comparisons, operations, and
conversions on simulation time values
transcript controls echoing of commands executed in a macro file; also
works at top level in batch mode
transcript file sets or queries the pathname for the transcript file
transcript path returns the full pathname to the current transcript file
transcript sizelimit sets or queries the current value for the transcript fileSizeLimit
value, saves file when limit is reached, and continues simulation
tssi2mti converts a vector file in Technology Standard Events Format
(TSSI) into a sequence of force and run commands
ui_VVMode specifies behavior when encountering user interface registration
calls used by verification packages, such as AVM or OVM
unsetenv deletes an environment variable
vcd add adds the specified objects to the VCD file
vcd checkpoint dumps the current values of all VCD variables to the VCD file
vcd comment inserts the specified comment in the VCD file
vcd dumpports creates a VCD file that captures port driver data

44 ModelSim Reference Manual, v10.1c

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
vcd dumpportsall creates a checkpoint in the VCD file that shows the current values
of all selected ports
vcd dumpportsflush flushes the VCD buffer to the VCD file
vcd dumpportslimit specifies the maximum size of the VCD file
vcd dumpportsoff turns off VCD dumping and records all dumped port values as x
vcd dumpportson turns on VCD dumping and records the current values of all
selected ports
vcd file specifies the filename and state mapping for the VCD file created
by a vcd add command
vcd files specifies filenames and state mapping for the VCD files created
by the vcd add command; supports multiple VCD files
vcd flush flushes the contents of the VCD file buffer to the VCD file
vcd limit specifies the maximum size of the VCD file
vcd off turns off VCD dumping and records all VCD variable values as x
vcd on turns on VCD dumping and records the current values of all VCD
variables
vcd2wlf translates VCD files into WLF files
vcom compiles VHDL design units
vdel deletes a design unit from a specified library
vdir lists the contents of a design library
vencrypt encrypts Verilog code contained within encryption envelopes
verror prints a detailed description of a message number
vgencomp writes the equivalent VHDL component declaration for a Verilog
module to standard output
vhencrypt encrypts VHDL code contained within encryption envelopes
view opens a ModelSim window and brings it to the front of the display
virtual count counts the number of currently defined virtuals that were not read
in using a macro file
virtual define prints the definition of a virtual signal or function in the form of a
command that can be used to re-create the object
virtual delete removes the matching virtuals
virtual describe prints a complete description of the data type of one or more
virtual signals

ModelSim Reference Manual, v10.1c 45

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
virtual expand produces a list of all the non-virtual objects contained in the
virtual signal(s)
virtual function creates a new signal that consists of logical operations on existing
signals and simulation time
virtual hide causes the specified real or virtual signals to not be displayed in
the Objects window
virtual log causes the sim-mode dependent signals of the specified virtual
signals to be logged by the simulator
virtual nohide redisplays a virtual previously hidden with virtual hide
virtual nolog stops the logging of the specified virtual signals
virtual region creates a new user-defined design hierarchy region
virtual save saves the definitions of virtuals to a file
virtual show lists the full path names of all the virtuals explicitly defined
virtual signal creates a new signal that consists of concatenations of signals and
subelements
virtual type creates a new enumerated type
vlib creates a design library
vlog compiles Verilog design units and SystemVerilog extensions
vmake creates a makefile that can be used to reconstruct the specified
library
vmap defines a mapping between a logical library name and a directory
vsim loads a new design into the simulator
vsim<info> returns information about the current vsim executable
vsim_break stop the current simulation before completion
vsource specifies an alternative file to use for the current source file
wave commands for manipulating cursors, for zooming, and for
adjusting the wave display view in the Wave window
when instructs ModelSim to perform actions when the specified
conditions are met
where displays information about the system environment
wlf2log translates a ModelSim WLF file to a QuickSim II logfile
wlf2vcd translates a ModelSim WLF file to a VCD file

46 ModelSim Reference Manual, v10.1c

Commands

Table 2-1. Supported Commands (cont.)

Command name Action
wlfman outputs information about or a new WLF file from an existing
WLF file
wlfrecover attempts to repair an incomplete WLF file
write format records the names and display options in a file of the objects
currently being displayed in the List or Wave window
write list records the contents of the List window in a list output file
write preferences saves the current GUI preference settings to a Tcl preference file
write report prints a summary of the design being simulated
write timing prints timing information about the specified instance
write transcript writes the contents of the Main window transcript to the specified
file
write tssi records the contents of the List window in a “TSSI format” file
write wave records the contents of the Wave window in PostScript format

ModelSim Reference Manual, v10.1c 47

Commands
abort

abort
This command halts the execution of a macro file interrupted by a breakpoint or error.
When macros are nested, you may choose to abort the last macro only, abort a specified number
of nesting levels, or abort all macros. You can specify this command within a macro to return
early.
Syntax
abort [<n> | all]
Arguments
• <n>
(optional) The number of nested macro levels to abort. Specified as an integer greater than
0, where the default value is 1.
• all
(optional) Instructs the tool to abort all levels of nested macros.
Related Topics
• onbreak
• onElabError
• onerror

48 ModelSim Reference Manual, v10.1c

Commands
add dataflow

add dataflow
This command adds the specified process, signal, net, or register to the Dataflow window.
Wildcards are allowed.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
add dataflow <object> ... [-connect <source_net> <destination_net>]
{[-in] [-out] [-inout] | [-ports]} [-internal] [-nofilter] [-recursive]
Arguments
• <object> ...
(required unless specifying -connect) Specifies a process, signal, net, or register to add to
the Dataflow window. Wildcards are allowed. Multiple objects are specified as a space
separated list, Refer to the section “Wildcard Characters” for wildcard usage as it pertains to
the add commands. Must be specified as the first argument to the add dataflow command.
• -connect <source_net> <destination_net>
(optional) Computes and displays in the Dataflow window all paths between two nets.
<source_net> — The net that originates the path search.
<destination_net> — The net that terminates the path search.
• -in
(optional) Specifies to add ports of mode IN.
• -inout
(optional) Specifies to add ports of mode INOUT.
• -out
(optional) Specifies to add ports of mode OUT.
• -ports
(optional) Specifies to add all ports. This switch has the same effect as specifying -in, -out,
and -inout together.
• -internal
(optional) Specifies to add internal (non-port) objects.
• -nofilter
(optional) Specifies that the WildcardFilter Tcl preference variable be ignored when finding
signals or nets.
The WildcardFilter Tcl preference variable identifies types to ignore when matching objects
with wildcard patterns.

ModelSim Reference Manual, v10.1c 49

Commands
add dataflow

• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region.
You can specify -r as an alias to this switch.
Examples
• Add all objects in the design to the dataflow window.
add dataflow -r /*

• Add all objects in the region to the dataflow window.

add dataflow *

Related Topics
• Automatically Tracing All Paths Between Two Nets
• Dataflow Window
• Using the WildcardFilter Preference Variable

50 ModelSim Reference Manual, v10.1c

Commands
add list

add list
This command adds the following objects and their values to the List window:
• VHDL signals and variables
• Verilog nets and registers
• User-defined buses
If you do not specify a port mode, such as -in or -out, this command displays all objects in the
selected region with names matching the object name specification.
Refer to “Wildcard Characters” for wildcard usage as it pertains to the add commands.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
add list {<object> ... | <object_name> {sig ...}} [-allowconstants] [-depth <level>]
{[-in] [-inout] [-out] | [-ports]} [-internal] [-label <name>] [-nodelta]
[-<radix_type> | -radix <type>] [-radixenumnumeric | -radixenumsymbolic] [-recursive]
[-trigger | -notrigger] [-width <integer>]
Arguments
• <object> ...
(required when <object_name >{sig ...} is not specified.) Specifies the name of the object to
be listed. Multiple objects are entered as a space separated list. Wildcards are allowed. Refer
to the section “Wildcard Characters” for wildcard usage as it pertains to the add commands.
Must be specified as the first argument to the add list command.
Note that the WildcardFilter Tcl preference variable identifies types to ignore when
matching objects with wildcard patterns.
You can add variables as long as they are preceded by the process name. For example:
add list myproc/int1

You must specify the <object> argument as the first argument to the add list command.
• <object_name> {sig ...}
(required when <object> is not specified) Creates a user-defined bus with the specified
object name containing the specified signals (sig) concatenated within the user-defined bus.
Arguments, must be enclosed in braces ({ }). Must be specified as the second argument to
the add list command.
sig — A space-separated list of signals, enclosed in braces ( {} ), that are included in the
user-defined bus. The signals may be either scalars or various sized arrays as long as
they have the same element enumeration type.
For example:
add list {mybus {a b y}}

ModelSim Reference Manual, v10.1c 51

Commands
add list

• -allowconstants
(optional) For use with wildcard searches. Specifies that constants matching the wildcard
search should be added to the List window.
This command does not add constants by default because they do not change.
• -depth <level>
(optional) Restricts a recursive search, as specified with -recursive, to a certain level of
hierarchy.
<level> — an integer greater than or equal to zero.
For example, if you specify -depth 1, the command descends only one level in the
hierarchy.
• -in
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode IN if they match the object specification.
• -inout
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode INOUT if they match the object specification.
• -out
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode OUT if they match the object specification.
• -ports
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include all ports. This switch has the same effect as specifying -in, -out, and -inout
together.
• -internal
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include internal objects (non-port objects) if they match the object specification. VHDL
variables are not selected.
• -label <name>
(optional) Specifies an alternative signal name to be displayed as a column heading in the
listing.
<name> — Specifies the label to be used at the top of the column. You must enclose
<name> in braces ( {} ) if it includes any spaces.
This alternative name is not valid in a force or examine command.
• -nodelta
(optional) Specifies that the delta column not be displayed when adding signals to the List
window. Identical to configure list -delta none.

52 ModelSim Reference Manual, v10.1c

Commands
add list

• -<radix_type>
(optional) Specifies the radix type for the objects that follow in the command. Valid entries
(or any unique abbreviations) are: binary, ascii, unsigned, decimal, octal, hex, symbolic,
time, and default.
If no radix is specified for an enumerated type, the default radix is used. You can change the
default radix for the current simulation using the radix command. You can change the
default radix permanently by editing the DefaultRadix variable in the modelsim.ini file.
If you specify a radix for an array of a VHDL enumerated type, ModelSim converts each
signal value to 1, 0, Z, or X.
• -radix <type>
(optional) Specifies a user-defined radix. The -radix <type> switch can be used in place of
the -<radix_type> switch. For example, -radix hexadecimal is the same as -hex.
<type> — binary, ascii, unsigned, decimal, octal, hex, symbolic, time, and default.
This option overrides the global setting of the default radix (the DefaultRadix variable in the
modelsim.ini file) for the current simulation only.
• -radixenumnumeric
This option overrides the global setting of the default radix (the DefaultRadix variable in the
modelsim.ini file).
• -radixenumsymbolic
(optional) Reverses the action of -radixenumnumeric and sets the global setting of the
default radix (the DefaultRadix variable in the modelsim.ini file) to symbolic.
• -recursive
(optional) For use with wildcard searches. Specifies that the scope of the search is to
descend recursively into subregions. If omitted, the search is limited to the selected region.
You can use the -depth argument to specify how far down the hierarchy to descend. You
can use "-r" as an alias to this switch.
• -trigger | -notrigger
(optional) Specifies whether objects should be updated in the List window when the objects
change value.
-trigger — (default) Update objects in the List Window when their values change.
-notrigger — Do not update objects in the List Window when their values change.
• -width <integer>
(optional) Formats the column width.
integer — A positive integer specifying the column width in characters.
Examples
• List all objects in the design.

ModelSim Reference Manual, v10.1c 53

Commands
add list

add list -r /*

• List all objects in the region.

add list *

• List all input ports in the region.

add list -in *

• Display a List window containing three columns headed a, sig, and array_sig(9 to 23).
add list a -label sig /top/lower/sig {array_sig(9 to 23)}

• List clk, a, b, c, and d only when clk changes.

add list clk -notrigger a b c d

• Lists clk, a, b, c, and d every 100 ns.

config list -strobeperiod {100 ns} -strobestart {0 ns} -usestrobe 1
add list -notrigger clk a b c d

• Creates a user-defined bus named "mybus" consisting of three signals; the bus is
displayed in hex.
add list -hex {mybus {msb {opcode(8 downto 1)} data}}

• Lists the object vec1 using symbolic values, lists vec2 in hexadecimal, and lists vec3 and
vec4 in decimal.
add list vec1 -hex vec2 -dec vec3 vec4

Related Topics
• add wave
• log
• Extended Identifiers
• Using the WildcardFilter Preference Variable

54 ModelSim Reference Manual, v10.1c

Commands
add memory

add memory
This command displays the contents and sets the address and data radix of the specified
memory in the MDI frame of the Main window.
Refer to “Wildcard Characters” for wildcard usage as it pertains to the add commands.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
add memory [-addressradix {decimal | hex}] [-dataradix <type>]
[-radixenumnumeric | -radixenumsymbolic] [-wordsperline <num>] <object_name> ...
Arguments
• -addressradix {decimal | hex}
(optional) Specifies the address radix for the memory display.
decimal — (default) Sets the radix to decimal. You can abbreviate this argument to "d".
hex — Sets the radix to hexadecimal. You can abbreviate this argument to "h".
• -dataradix <type>
(optional) Specifies the data radix for the memory display. If you do not specify this switch,
the command uses the global default radix.
<type> — binary, ascii, unsigned, decimal, octal, hex, symbolic, time, and default.
If you do not specify a radix for an enumerated type, the command uses the symbolic
representation.
You can change the default radix for the current simulation using the radix command. You
can change the default radix permanently by editing the DefaultRadix variable in the
modelsim.ini file. Changing the default radix does not change the radix of the currently
displayed memory. Use the add memory command to re-add the memory with the desired
radix, or change the display radix from the Memory window Properties dialog.
• -radixenumnumeric
(optional) Causes Verilog and SystemC enums to be displayed as numbers (formatted by the
current radix). This overrides the default behavior of always showing enums symbolically.
• -radixenumsymbolic
(optional) Restores the default behavior of displaying Verilog and SystemC enums as
symbols by reversing the action of the -radixenumnumeric option.
• -wordsperline <num>
(optional) Specifies how many words are displayed on each line in the memory window. By
default, the information displayed will wrap depending on the width of the window.
num — Any positive integer

ModelSim Reference Manual, v10.1c 55

Commands
add memory

• <object_name> ...
(required) Specifies the hierarchical path of the memory to be displayed. Multiple memories
are specified as a space separated list. Must be specified as the final argument to the add
memory command.
Wildcard characters are allowed.
Note
The WildcardFilter Tcl preference variable identifies types to ignore when matching
objects with wildcard patterns.)

Related Topics
• Memory List Window
• Using the WildcardFilter Preference Variable

56 ModelSim Reference Manual, v10.1c

Commands
add message

add message
This command is used within a macro or script and specifies a user defined runtime message
that is sent to the transcript and .wlf files. Messages are displayed in the Message Viewer
window in the GUI. Refer to “Message Viewer Window” for information.
Syntax
add message <message_body> [-category <category>] [-efftime <time>] [-file <filename>]
[-id <id_number>] [-inline] [-line <linenumber>] [-noident] [-nolevel] [-objects <list>]
[-region region] [-severity {error | note | warning}]
Arguments
• <message_body>
(required) User specified message.
• -category <category>
(optional) Sets the category for the message in the Message Viewer window where the
default is USER. The Message Viewer window Category column recognizes the following
keywords:
Table 2-2. Message Viewer Categories
DISPLAY FLI PA
PLI SDF TCHK
VCD VITAL WLF
MISC USER <user-defined>

• -efftime <time>
(optional) Specifies the simulation time when the message is saved to the log file. The time
specified is listed in the Message Viewer window Time column when the message is called.
Useful for placing messages at specific times in the simulation.
<time> — Specified as an integer or decimal number.
• -file <filename>
(optional) Displays a user specified string in the File Info column of the Message Viewer
window.
• -id <id_number>
(optional) Assigns an identification number to the message.
<id_number> — Any non-negative integer from 0 - 9999 where the default is 0. The
number specified is added to the base identification number of 80000.
• -inline
(optional) Causes the message to also be returned to the caller as the return value of the add
message command.

ModelSim Reference Manual, v10.1c 57

Commands
add message

• -line <linenumber>
(optional) Displays the user specified number in File Info column of the Message Viewer
window.
• -noident
(optional) Prevents return of the ID number of the message.
• -nolevel
(optional) Prevents return of the severity level of the message.
• -objects <list>
(optional) List of related design items shown in the Objects column of the Message Viewer
window.
<list> — A space separated list enclosed in curly braces ({}) or quotation marks
(" ").
• -region region
(optional) Message is displayed in the Region column of the Message Viewer window.
• -severity {error | note | warning}
(optional) Sets the message severity level.
error — ModelSim cannot complete the operation.
note — (default) The message is informational.
warning — There may be a problem that will affect the accuracy of the results.
Examples
• Create a message numbered 80304.
add message -id 304 <message>

Related Topics
• displaymsgmode modelsim.ini variable
• msgmode modelsim.ini variable
• Message Viewer Window

58 ModelSim Reference Manual, v10.1c

Commands
add watch

add watch
This command adds signals and variables to the Watch window in the Main window.
Refer to “Wildcard Characters” for wildcard usage as it pertains to the add commands.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
add watch <object_name> ... [-radix <type>] [-radixenumnumeric | -radixenumsymbolic]
Arguments
• <object_name> ...
(required) Specifies the name of the object to be added. Multiple objects are entered as a
space separated list. Must be specified as the first argument to the add watch command.
Wildcard characters are allowed. (Note that the WildcardFilter Tcl preference variable
identifies types to ignore when matching objects with wildcard patterns.)
Variables must be preceded by the process name. For example,
add watch myproc/int1

• -radix <type>
(optional) Specifies a user-defined radix. If you do not specify this switch, the command
uses the global default radix.
<type> — binary, ascii, unsigned, decimal, octal, hex, symbolic, time, and default.
You can change the default radix for the current simulation using the radix command. You
can change the default radix permanently by editing the DefaultRadix variable in the
modelsim.ini file.
• -radixenumnumeric
(optional) Causes Verilog and SystemC enums to be displayed as numbers (formatted by the
current radix). This overrides the default behavior of always showing enums symbolically.
• -radixenumsymbolic
(optional) Restores the default behavior of displaying Verilog and SystemC enums as
symbols by reversing the action of the -radixenumnumeric option.
Related Topics
• Watch window • Wildcard Characters
• Using the WildcardFilter Preference • DefaultRadix variable
Variable

ModelSim Reference Manual, v10.1c 59

Commands
add wave

add wave
This command adds the following objects to the Wave window:
• VHDL signals and variables
• Verilog nets and registers
• SystemVerilog class objects
• Dividers and user-defined buses.
If no port mode is specified, this command will display all objects in the selected region with
names matching the object name specification.
Refer to “Wildcard Characters” for wildcard usage as it pertains to the add commands.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
add wave [-allowconstants] [-clampanalog {0 | 1}] [-color <standard_color_name>]
[-depth <level>] [[-divider [<divider_name> ...] [-expand <signal_name>]
[-format <type> | -<format>] [-group <group_name> [<sig_name1> ...]] [-height <pixels>]
{[-in] [-inout] [-out] | [-ports]} [-internal] [-label <name>][-max <real_num>]
[-min <real_num>][-noupdate] [-position <location>]
[-<radix_type> | -radix <type>] [-radixenumnumeric | -radixenumsymbolic] [-recursive]
[-time] [<object_name> ...] [{<object_name> {sig1 sig2 ...}}]
Arguments
• -allowconstants
(optional) For use with wildcard searches. Specifies that constants matching the wildcard
search should be added to the Wave window.
By default, constants are ignored because they do not change.
• -clampanalog {0 | 1}
(optional) Clamps the display of an analog waveform to the values specified by -max and
-min. Specifying a value of 1 prevents the waveform from extending above the value
specified for -max or below the value specified for -min.
0 — not clamped
1 — (default) clamped
• -color <standard_color_name>
(optional) Specifies the color used to display a waveform.
<standard_color_name> — You can use either of the following:
standard X Window color name — enclose 2-word names in quotes ("), for example:
-color "light blue"

60 ModelSim Reference Manual, v10.1c

Commands
add wave

rgb value — for example:

-color #357f77

• -depth <level>
(optional) Restricts a recursive search, as specified with -recursive to a specified level of
hierarchy.
<level> — Any integer greater than or equal to zero. For example, if you specify
-depth 1, the command descends only one level in the hierarchy.
• -divider [<divider_name> ...]
(optional) Adds a divider to the Wave window. If you do not specify this argument, the
command inserts an unnamed divider.
<divider_name> ... — Specifies the name of the divider, which appears in the
pathnames column. Multiple objects entered as a space separated list.
When you specify more than one <divider_name> the command creates a divider for
each name.
You can begin a name with a space, but you must enclose the name within quotes (")
or braces ({ }) You cannot begin a name with a hyphen (-).
• -expand <signal_name>
(optional) Instructs the command to expand a compound signal immediately, but only one
level down.
<signal_name> — Specifies the name of the signal. This string can include wildcards.
• -format <type> | -<format>
(optional) Specifies the display format of the objects. Valid entries are:
-format <type> -<format> Display Format
-format literal -literal Literal waveforms are displayed
as a box containing the object
value.
-format logic -logic Logic signals may be U, X, 0, 1,
Z, W, L, H, or ‘-’.
-format analog-step -analog-step Analog-step changes to the new
time before plotting the new Y.
-format analog-interpolated -analog-interpolated Analog-interpolated draws a
diagonal line.
-format analog-backstep -analog-backstep Analog-backstep plots the new
Y before moving to the new
time.
-format event -event Displays a mark at every
transition.

ModelSim Reference Manual, v10.1c 61

Commands
add wave

The Y-axis range of analog signals is bounded by -max and -min switches.
• -group <group_name> [<sig_name1> ...]
(optional) Creates a wave group with the specified group_name.
<group_name> — Specifies the name of the group. You must enclose this argument in
quotes (") or braces ({ }) if it contains any spaces.
<sig_name> ... — Specifies the signals to add to the group. Multiple signals are entered
as a space separated list. This command creates an empty group if you do not specify
any signal names.
• -height <pixels>
(optional) Specifies the height of the waveform in pixels.
<pixels> — Any positive integer.
• -in
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode IN if they match the object_name specification.
• -out
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode OUT if they match the object_name specification.
• -inout
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include ports of mode INOUT if they match the object_name specification.
• -ports
(optional) For use with wildcard searches. Specifies that the scope of the listing is to
include ports of modes IN, OUT, or INOUT.
• -internal
(optional) For use with wildcard searches. Specifies that the scope of the search is to
include internal objects (non-port objects) if they match the object_name specification.
• -label <name>
(optional) Specifies an alternative name for the signal being added. For example,
add wave -label c clock

adds the clock signal, labeled as "c".

This alternative name is not valid in a force or examine command.
• -max <real_num>
(optional) Specifies the maximum Y-axis data value to be displayed for an analog
waveform. Used in conjunction with the -min switch; the value you specify for -max must
be greater than the value you specify for -min.
<real_num> — Any integer that is greater than the value specified for -min.

62 ModelSim Reference Manual, v10.1c

Commands
add wave

• -min <real_num>
(optional) Specifies the minimum Y-axis data value to be displayed for an analog
waveform. Used in conjunction with the -max switch; the value you specify for -min must
be less than the value you specify for -max.
<real_num> — Any integer that is less than the value specified for -max.
For example, if you know the Y-axis data for a waveform varies between 0.0 and 5.0, you
could add the waveform with the following command:
add wave -analog -min 0 -max 5 -height 100 my_signal

Note
Although -offset and -scale are still supported, the -max and -min arguments provide an
easier way to define upper and lower limits of an analog waveform.

• -noupdate
(optional) Prevents the Wave window from updating when a series of add wave commands
are executed in series.
• -position <location>
(optional) Specifies where the command adds the signals.
<location> — Can be any of the following:
top — Adds the signals to the beginning of the list of signals.
bottom | end — Adds the signals to the end of the list of signals.
before | above — Adds the signals to the location before the first selected signal in the
wave window.
after | below — Adds the signals to the location after the first selected signal in the
wave window.
<integer> — Adds the signals beginning at the specified point in the list of signals.
• -<radix_type>
(optional) Specifies the radix type for the objects that follow in the command. Valid entries
(or any unique abbreviations) are: binary, ascii, unsigned, decimal, octal, hex, symbolic,
time, and default.
If no radix is specified for an enumerated type, the default radix is used. You can change the
default radix for the current simulation using the radix command. You can change the
default radix permanently by editing the DefaultRadix variable in the modelsim.ini file.
If you specify a radix for an array of a VHDL enumerated type, ModelSim converts each
signal value to 1, 0, Z, or X.
• -radix <type>
(optional) Specifies a user-defined radix. The -radix <type> switch can be used in place of
the -<radix_type> switch. For example, -radix hexadecimal is the same as -hex.

ModelSim Reference Manual, v10.1c 63

Commands
add wave

<type> — binary, ascii, unsigned, decimal, octal, hex, symbolic, time, and default.
This option overrides the global setting of the default radix (the DefaultRadix variable in the
modelsim.ini file) for the current simulation only.
• -radixenumnumeric
(optional) Causes Verilog and SystemC enums to be displayed as numbers (formatted by the
current radix). This overrides the default behavior of always showing enums symbolically.
• -radixenumsymbolic
(optional) Restores the default behavior of displaying Verilog and SystemC enums as
symbols by reversing the action of the -radixenumnumeric option.
• -recursive
(optional) For use with wildcard searches. Specifies that the scope of the search is to
descend recursively into subregions.
If you do not specify this switch, the search is limited to the selected region. You can use the
-depth argument to specify how far down the hierarchy to descend.
• -time
(optional) Use time as the radix for Verilog objects that are register-based types (register
vectors, time, int, and integer types).
• <object_name> ...
(required unless specifying {<object_name> {sig1 sig2 ...}) Specifies the names of objects
to be included in the Wave window. Must be specified as the final argument to the add
wave command. Wildcard characters are allowed. Multiple objects are entered as a space
separated list. Note that the WildcardFilter Tcl preference variable identifies types to ignore
when matching objects with wildcard patterns.
Variables may be added if preceded by the process name. For example,
add wave myproc/int1

• {<object_name> {sig1 sig2 ...}}

(required unless specifying <object_name>) Creates a user-defined bus with the specified
object name containing the specified signals (sig1 and so forth) concatenated within the
user-defined bus. Must be specified as the final argument to the add wave command.
sig — A space-separated list of signals, enclosed in braces ({ }), that are included in the
user-defined bus. The signals may be either scalars or various sized arrays as long as
they have the same element enumeration type.
Note
You can also select Wave > Combine Signals (when the Wave window is selected) to
create a user-defined bus.

64 ModelSim Reference Manual, v10.1c

Commands
add wave

Examples
• Display an object named out2. The object is specified as being a logic object presented
in gold.
add wave -logic -color gold out2

• Display a user-defined, hex formatted bus named address.

add wave -hex {address {a_7 a_6 a_5 a_4 a_3 a_2 a_1 a_0}}

• Add all wave objects in the region.

add wave *

• Add all wave input ports in the region.

add wave -in *

• Create a user-defined bus named "mybus" consisting of three signals. Scalar1 and
scalar2 are of type std_logic and vector1 is of type std_logic_vector (7 downto 1). The
bus is displayed in hex.
add wave -hex {mybus {scalar1 vector1 scalar2}}

Slices and arrays may be added to the bus using either VHDL or Verilog syntax. For
example:
add wave {vector3(1)}
add wave {vector3[1]}
add wave {vector3(4 downto 0)}
add wave {vector3[4:0]}

• Add the object vec1 to the Wave window using symbolic values, adds vec2 in
hexadecimal, and adds vec3 and vec4 in decimal.
add wave vec1 -hex vec2 -dec vec3 vec4

• Add a divider with the name "-Example-". Note that for this to work, the first hyphen of
the name must be preceded by a space.
add wave -divider " -Example- "

• Add an unnamed divider.

add wave -divider
add wave -divider ""
add wave -divider {}

ModelSim Reference Manual, v10.1c 65

Commands
add wave

Related Topics
• add list
• log
• Concatenation Directives
• Extended Identifiers
• Using the WildcardFilter Preference Variable
• Refer to Wave Window for more information on
analog formats of waveform signals.

66 ModelSim Reference Manual, v10.1c

Commands
add_cmdhelp

add_cmdhelp
This command adds the specified command name, description, and command arguments to the
command-line help. You can then access the information using the help command.
To delete an entry, invoke the command with an empty command description and arguments.
See examples.
The arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
add_cmdhelp {<command_name>} {<command_description>} {<command_arguments>}
Arguments
• {<command_name>}
(required) Specifies the command name that will be entered as an argument to the help
command. Must be enclosed in braces ({ }). The command_name must not interfere with an
already existing command_name. Must be specified as the first argument to the
add_cmdhelp command.
• {<command_description>}
(required) Specifies a description of the command. Must be enclosed in braces ({ }). Must
be specified as the second argument to the add_cmdhelp command.
• {<command_arguments>}
(required) A space-separated list of arguments for the command. Must be enclosed in braces
({ }). If the command doesn’t have any arguments, enter {}. Must be specified as the third
argument to the add_cmdhelp command.
Examples
• Add a command named "date" with no arguments.
add_cmdhelp date {Displays date and time.} {}

Entering:
VSIM> help date

returns:
Displays date and time.
Usage: date

• Add the change date command.

add_cmdhelp {change date} {Modify date or time.} {-time|-date <arg>}

Entering:
VSIM> help change date

ModelSim Reference Manual, v10.1c 67

Commands
add_cmdhelp

returns:
Modify data or time.
Usage: change date -time|-date <arg>

• Deletes the change date command from the command-line help.

add_cmdhelp {change date} {} {}

68 ModelSim Reference Manual, v10.1c

Commands
alias

alias
This command displays or creates user-defined aliases. Any arguments passed on invocation of
the alias will be passed through to the specified commands.
Returns nothing. Existing commands (e.g., run, env, etc.) cannot be aliased.
Syntax
alias [<name> ["<cmds>"]]
Arguments
• <name>
(optional) Specifies the new procedure name to be used when invoking the commands.
• "<cmds>"
(optional) Specifies the command or commands to be evaluated when the alias is invoked.
Multiple commands are specified as a semicolon (;) separated list. You must enclose the
string in quotes (““).
Examples
• List all aliases currently defined.
alias

• List the alias definition for the specified name if one exists.
alias <name>

• Create a Tcl procedure, "myquit", that when executed, writes the contents of the List
window to the file mylist.save by invoking write list, and quits ModelSim by invoking
quit.
alias myquit "write list ./mylist.save; quit -f"

ModelSim Reference Manual, v10.1c 69

Commands
archive load

archive load
The archive load command allows you to load an archived debug database (.dbg) file that was
previously created with the archive write command.
Syntax
archive load <archive_name> [-dbgDir <directory_name>] -wlfFiles <wlf_file_name>
Arguments
• <archive_name>
Specifies the name of the archived file to be opened for reading.
• -dbgDir <directory_name>
(optional) Specifies a location to extract files into. Files are extracted on-demand when
Modelsim needs them. The current working directory is used if the switch is not specified.
• -wlfFiles <wlf_file_name
(optional) Specifies the WLF files to open for analysis. The argument can be a single file or
a list of files. A list of file names must be enclosed in curly braces {}. The name of the wlf
file must be exactly the same as that specified in the archive write command, including the
pathname, if provided.

70 ModelSim Reference Manual, v10.1c

Commands
archive write

archive write
The archive write command allows you to create a debug archive file, with the file extension
.dgb, that contains one or more WLF files, debug information captured from the design library,
an optional connectivity debug database file, and optional HDL source files. With this archived
file, you can perform post-simulation debugging in different location from that which the
original simulation was run.
Syntax
archive write <archive_name> -wlf <wlf_file_name> [-include_src] [-dbg <dbg _file_name>]
Arguments
• <archive_name>
Specifies the name of the archived file to be created.
• -wlf <wlf_file_name>
Specifies the name of the WLF file to use for post-simulation analysis. <wlf_file_name>
may be a list of files enclosed in curly braces {} if you want to capture more than one WLF
file in the archive.
• -include_src
(optional) Indicate if source files should be captured in the archive. This is off by default,
which means no source will be in the archive.
• -dbg <dbg_file_name>
(optional) Specifies the name of an existing debug database (.dbg) file to be included in the
archive.

ModelSim Reference Manual, v10.1c 71

Commands
batch_mode

batch_mode
This command returns “1” if ModelSim is operating in batch mode, otherwise it returns “0.” It
is typically used as a condition in an if statement.
Syntax
batch_mode
Arguments
None
Examples
Some GUI commands do not exist in batch mode. If you want to write a script that will work in
or out of batch mode, you can use the batch_mode command to determine which command to
use. For example:
if [batch_mode] {
log /*
} else {
add wave /*
}

Related Topics
• Modes of Operation

72 ModelSim Reference Manual, v10.1c

Commands
bd

bd
This command deletes a breakpoint. You can delete multiple breakpoints by specifying separate
information groupings on the same command line.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
bd {<filename> <line_number>}
bd {<id_number> | <label>} ...
Arguments
• <filename>
(required when not specifying <id_number> or <label>.) A string that specifies the name
of the source file in which the breakpoint is to be deleted. The filename must match the one
used previously to set the breakpoint, including whether you used a full pathname or a
relative name. Must be specified as the first argument to the bd command.
• <line_number>
(required) A string that specifies the line number of the breakpoint to be deleted.
• <id_number> | <label>
(required when not specifying <filename>.) Specifies the identification of breakpoints
using markers assigned by the bp command. Must be specified as the first argument to the
bd command.
<id_number — A string that specifies the identification number of the breakpoint to be
deleted. The identification number is set with the -id argument to the bp command.
<label> — A string that specifies the label of the breakpoint to be deleted. The label is
set with the -label switch to the bp command.
Examples
• Delete the breakpoint at line 127 in the source file named alu.vhd.
bd alu.vhd 127

• Delete the breakpoint with id# 5.

bd 5

• Delete the breakpoint with the label top_bp

bd top_bp

• Delete the breakpoint with id# 6 and the breakpoint at line 234 in the source file named
alu.vhd.

ModelSim Reference Manual, v10.1c 73

Commands
bd

bd 6 alu.vhd 234

Related Topics
• bp
• onbreak

74 ModelSim Reference Manual, v10.1c

Commands
bookmark add wave

bookmark add wave

This command creates a named reference to a specific zoom range and scroll position in the
specified Wave window. Bookmarks are saved in the wave format file and are restored when
the format file is read.
You can also interactively add a bookmark through the GUI by selecting the
Wave > Bookmarks > Bookmarks menu item.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
bookmark add wave <label> [[<range_start> [<unit>]] [<range_end> [<unit>]] [<topindex>]]

Arguments
• <label>
(required) A string that specifies the name for the bookmark. Must be specified as the first
argument to the bookmark add wave command.
• <range_start> [<unit>]
(optional) Specifies the beginning point of the zoom range where the default starting point is
zero ( 0 ).
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <limit> and <unit>
within curly braces ({}).
The complete grouping of <range_start> and <range_end> must also be enclosed in braces
({ }) or quotes (" "), for example:
{{100 ns} {10000 ns}}
{10000}

• <range_end> [<unit>]
(optional) Specifies the end point of the zoom range.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <limit> and <unit>
within curly braces ({}).
• <topindex>
(optional) An integer that specifies the vertical scroll position of the window. You must
specify a zoom range to specify topindex. The number identifies which object the window
should be scrolled to. For example, specifying 20 means the Wave window will be scrolled
down to show the 20th object.

ModelSim Reference Manual, v10.1c 75

Commands
bookmark add wave

Examples
• Add a bookmark named "foo" to the current default Wave window. The bookmark
marks a zoom range from 10ns to 1000ns and a scroll position of the 20th object in the
window.
bookmark add wave foo {{10 ns} {1000 ns}} 20

Related Topics
• bookmark delete wave
• bookmark goto wave
• bookmark list wave
• write format

76 ModelSim Reference Manual, v10.1c

Commands
bookmark delete wave

bookmark delete wave

This command deletes bookmarks from the specified Wave window.
You can also interactively delete a bookmark through the GUI by selecting the
Wave > Bookmarks > Bookmarks menu item.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
bookmark delete wave {<label> | -all}
Arguments
• <label> | -all
(required) Controls which bookmarks to delete. Must be specified as the first argument to
the bookmark delete wave command.
<label> — Specifies the name of the bookmark to delete.
-all — Specifies that all bookmarks in the window be deleted.
Examples
• Delete the bookmark named "foo" from the current default Wave window.
bookmark delete wave foo

Related Topics
• bookmark add wave
• bookmark goto wave
• bookmark list wave
• write format

ModelSim Reference Manual, v10.1c 77

Commands
bookmark goto wave

bookmark goto wave

This command zooms and scrolls a Wave window using the specified bookmark.
You can also interactively navigate between bookmarks through the GUI by selecting the
Wave > Bookmarks > Bookmarks menu item.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
bookmark goto wave <label>
Arguments
• <label>
(required) Specifies the bookmark to go to. Must be specified as the first argument to the
bookmark goto wave command.
Related Topics
• bookmark add wave
• bookmark delete wave
• bookmark list wave
• write format

78 ModelSim Reference Manual, v10.1c

Commands
bookmark list wave

bookmark list wave

This command displays a list of available bookmarks in the Transcript window.
Syntax
bookmark list wave
Related Topics
• bookmark add wave
• bookmark delete wave
• bookmark goto wave
• write format

ModelSim Reference Manual, v10.1c 79

Commands
bp

bp
This command sets either a file-line breakpoint or returns a list of currently set breakpoints. It
allows enum names, as well as literal values, to be used in condition expressions.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
Setting an HDL breakpoint
bp {<filename> <line_number>}[-appendinst] [-cond "<condition_expression>"] [-disable]
[-id <id_number> | -label "<label>"] [-inst <region> [-inst <region> ...]] [<command>…]
Querying a breakpoint
bp [-query <filename> [<line_number>]]

Reporting all breakpoints

If you specify this command with no arguments, it returns a list of all breakpoints in the
design containing information about each breakpoint. For example:
bp

returns:
# bp top.vhd 70;# 2

o bp — an echo of the command

o <file_name>
o <line_number>
o # <id_number>
Arguments
• <filename>
(required to set an HDL breakpoint) Specifies the name of the source file in which to set the
breakpoint. Must be specified as the first argument to the bp command.
• <line_number>
(required to set an HDL breakpoint) Specifies the line number where the breakpoint is to be
set. Must be specified as the second argument to the bp command.
• -appendinst
(optional) When specifying multiple breakpoints with -inst, append each instance-path
condition to the earlier condition. This overrides the default behavior, in which each
condition overwrites the previous one.

80 ModelSim Reference Manual, v10.1c

Commands
bp

• -disable
(optional) Sets the breakpoint to a disabled state. You can enable the breakpoint later using
the enablebp command. This command enables breakpoints by default.
• <command>…
(optional, must be specified as the final argument) Specifies one or more commands that are
to be executed at the breakpoint. You must separate multiple commands with semicolons (;)
or place them on multiple lines. Braces are required only if the string contains spaces.
Note
You can also specify this command string by choosing Tools > Breakpoints... from the
main menu and using the Modify Breakpoints dialog box.

Any commands that follow a run or step command are ignored. A run or step command
terminates the breakpoint sequence. This rule also applies if you use a macro within the
command string.
If many commands are needed after the breakpoint, you could place them in a macro file.
• -cond "<condition_expression>"
(optional) Specifies one or more conditions that determine whether the breakpoint is hit.
"<condition_expression>" — A conditional expression that results in a true/false value.
You must enclose the condition expression within braces ( {} ) or quotation marks
(“ ”) when the expression makes use of spaces. Refer to the note below when setting
breakpoints in the GUI.
If the condition is true, the simulation stops at the breakpoint. If false, the simulation
bypasses the breakpoint. A condition cannot refer to a VHDL variable (only a signal).
The -cond switch re-parses expressions each time the breakpoint is hit. This allows
expressions with local references to work. Condition expressions referencing items outside
the context of the breakpoint must use absolute names. This is different from the behavior in
previous ModelSim versions where a relative signal name was resolved at the time the bp
command was issued, allowing the breakpoint to work even though the relative signal name
was inappropriate when the breakpoint was hit.
Note
You can also specify this expression by choosing Tools > Breakpoints... from the main
menu and entering the expression in the Breakpoint Condition field of the Modify
Breakpoints dialog box. Do not enclose the condition expression in quotation marks
(“ ”) or braces ( {} ).

The condition expression can use the following operators:

Operation Operator Syntax
equals ==, =

ModelSim Reference Manual, v10.1c 81

Commands
bp

Operation Operator Syntax

not equal !=, /=
AND &&, AND
OR ||, OR
The operands may be object names, signame’event, or constants. Subexpressions in
parentheses are permitted. The command will be executed when the expression is evaluated
as TRUE or 1. The formal BNF syntax for an expression is:
condition ::= Name | { expression }

expression ::= expression AND relation

| expression OR relation
| relation
relation ::= Name = Literal
| Name /= Literal
| Name ' EVENT
| ( expression )
Literal ::= '<char>' | "<bitstring>" | <bitstring>

The "=" operator can occur only between a Name and a Literal. This means that you cannot
compare the value of two signals (for example, Name = Name is not valid).
You can construct a breakpoint such that the simulation breaks when a SystemVerilog Class
is associated with a specific handle, or address:
bp <filename> <line_number> -cond "this==<class_handle>"
bp <filename> <line_number> -cond "this!=<class_handle>"

where you can obtain the class handle with the examine -handle command. The string "this"
is a literal that refers to the specific line_number.
You can construct a breakpoint such that the simulation breaks when a line number is of a
specific class type or extends the specified class type:
bp <filename> <line_number> -cond "this ISA <class_type_name>"

where class_type_name is the actual class name, not a variable.

• -id <id_number> | -label "<label>"
(optional) Attempts to assign an id number or label to the breakpoint. The command returns
an error if the id number you specify is already assigned.
-id <id_number> — Any positive integer that is not already assigned.
-label "<label>" — Associates a name or label with the specified breakpoint. Adds a
level of identification to the breakpoint. The label may contain special characters.
Quotation marks (" ") or braces ({ }) are required only if <label> contains spaces or
special characters.

82 ModelSim Reference Manual, v10.1c

Commands
bp

Note
Id numbers for breakpoints are assigned from the same pool as those used for the when
command. So even if you have not specified a given id number for a breakpoint, that
number may still be used for a when command.

• -inst <region> [-inst <region> ...]

(optional) Sets an HDL breakpoint so it applies only to the specified instance. To apply
multiple instance-path conditions on a single breakpoint, specify -inst <region> multiple
times. By default, this overrides the previous breakpoint condition (you can use the -
appendinst argument to append conditions instead).
<region> — The full path to the instance specified.
Note
You can also specify this instance by choosing Tools > Breakpoints... from the main
menu and using the Modify Breakpoints dialog box.

• -query <filename> [<line_number>]

(optional) Returns information about the breakpoint(s) set in the specified file. The
information returned varies depending on the condition of the breakpoint(s) in the specified
file. Returns a complete list of all breakpoints and whether they are enabled or not when
specified without <line_number>. Returns nothing if <line_number> is not executable.
<filename> — The name of the file containing the breakpoint.
<line_number> — The line number where a breakpoint has been set.
The output contains six fields of information. For example:
bp -query top.vhd 70

returns
# 1 1 top.vhd 70 2 1

o {1 | 0} — Indicates whether a breakpoint exists at the location.

0 — Breakpoint does not exit.
1 — Breakpoint exists.
o 1 — always reports a 1.
o <file_name>
o <line_number>
o <id_number>
o {1 | 0} — Indicates whether the breakpoint is enabled.
0 — Breakpoint is not enabled.

ModelSim Reference Manual, v10.1c 83

Commands
bp

1 — Breakpoint is enabled.
Examples
• List all existing breakpoints in the design, including the source file names, line numbers,
breakpoint id#s, labels, and any commands that have been assigned to the breakpoints.
bp

• Set a breakpoint in the source file alu.vhd at line 147.

bp alu.vhd 147

• Execute the macro.do macro file when the breakpoint is hit.

bp alu.vhd 147 {do macro.do}

• Set a breakpoint on line 22 of test.vhd. When the breakpoint is hit, the values of
variables var1 and var2 are examined. This breakpoint is initially disabled; it can be
enabled with the enablebp command.
bp -disable test.vhd 22 {echo [exa var1]; echo [exa var2]}

• Set a breakpoint so that the simulation pauses whenever clk=1 and prdy=0:
bp test.vhd 14 -cond {clk=1 AND prdy=0}

• Set a breakpoint with the label top_bp

bp top.vhd 14 -label top_bp

• Set a breakpoint for line 15 of a.vhd, but only for the instance a2:
bp a.vhd 15 -inst "/top/a2"

• Set multiple breakpoints in the source file test.vhd at line 14. The second instance will
overwrite the conditions of the first.
bp test.vhd 14 -inst /test/inst1 -inst /test/inst2

• Set multiple breakpoints at line 14. The second instance will append its conditions to the
first.
bp test.vhd 14 -inst /test/inst1 -inst /test/inst2 -appendinst

• Set a breakpoint for a specific variable of a particular class type:

set x [examine -handle my_class_var]
bp top.sv 15 -cond {this == $x}

• List the line number and enabled/disabled status (1 = enabled, 0 = disabled) of all
breakpoints in testadd.vhd.
bp -query testadd.vhd

• List details about the breakpoint on line 48.

bp -query testadd.vhd 48

84 ModelSim Reference Manual, v10.1c

Commands
bp

• List all executable lines in testadd.vhd between lines 2 and 59.

bp -query testadd.vhd 2 59

Note
Any breakpoints set in VHDL code and called by either resolution functions or functions
that appear in a port map are ignored.

Related Topics
• bd
• disablebp
• enablebp
• Editing File-Line Breakpoints
• onbreak
• when

ModelSim Reference Manual, v10.1c 85

Commands
call

call
This command calls SystemVerilog static functions and class functions directly from the vsim
command line in live simulation mode. Tasks are not supported.
Function return values are returned to the vsim shell as a Tcl string. If the function returns a
class reference, the class instance ID is returned.
Syntax
Calling a function
call <pathToFunction> [classInstancePath] [functionArg0] [functionArg1] ...
Arguments
• pathToFunction
(required) The name of a function. The function name may be qualified in one of three
ways:
1. By specifying the path to the function declaration, through the structural hierarchy, or
declaration hierarchy. Hierarchical paths must be specified as a full path to a function or
a function that exists relative to the current context (as shown in the Structure window,
or returned by the environment command).
2. By specifying a class instance hierarchical path.
3. By specifying a class instance id string.
• classInstancePath
(optional) Must be specified if the function path is a declaration path and the function is a
non-static class function. Conversely, the class instance path name must not be specified if
the given function path is a class instance variable reference or a class instance name in the
format @<class_type>@nnn. This is because the class instance information can be
extracted from the pathname itself.
• functionArg0 functionArg1 ...
(optional) All arguments required by the function are specified in a space separated list in
declaration order. If a function has default arguments, the arguments may be omitted from
the command line provided that the arguments occur at the end of the declaration list.
Function input arguments can be constant values including integers, enumerated values, and
strings. A string containing spaces or special characters must be enclosed in double quotes
(" ") or braces ( { } ) or Tcl will try to interpret the string. For example: "my string" or {my
string}. Arguments can also be design objects. Class references can be arguments, specified
by either their design instance path or class instance id string. If a function has type inout,
out, or ref arguments, suitable user design objects must be passed in as arguments. Any
passed in argument will first be tested to determine if it is an appropriate constant value. If it
is not, then the argument will be tested to determine if it is a design object. Consequently,
where there is ambiguity between a constant string and the name of a design object, the

86 ModelSim Reference Manual, v10.1c

Commands
call

constant will be given precedence. If in this case the design object is desired, the full
hierarchical path to the object can be supplied to differentiate it from the constant string.
Examples
• Call using a static declaration path, where the function sf_voidstring() is a static class
function that accepts a string:
call sim:/user_pkg::myfcns::sf_voidstring first_string

• Call using a class instance path to specify the function, where the function f_intint() of
the class type /utop/tmyfcns accepts an integer:
call /utop/tmyfcns.f_intint 37

• Call using a class instance path to specify the function, and pass in a class instance
(/utop/tmyfcns is a class handle):
call /utop/tmyfcns.f_voidclasscolor /utop/tmyfcns

• Call using a class instance path, and pass in a class instance as an argument using a class
instance id string
call /utop/tmyfcns.f_voidclasscolor @myType@3

• Call using a class instance id string to specify the function:

call @myType@543.get_full_name

• Call using a declaration path, where the function is non-static so a class instance must
also be supplied. The member function f_voidstring() accepts a string:
call sim:/user_pkg::myfcns::f_voidstring /my/class/instance "some string"

• Call using a class instance id string to specify the function where the function returns a
string:
VSIM> call @uvm_sequencer__3@3.get_full_name

Returns:
# test.e2_a.sequencer

• Call using a relative class hierarchical name to specify the function where the function
returns a class handle:
VSIM> call moduleX.who_am_i

Returns:
# @myClassX@4

ModelSim Reference Manual, v10.1c 87

Commands
cd

cd
This command changes the ModelSim local directory to the specified directory.
This command cannot be executed while a simulation is in progress. Also, executing a cd
command will close the current project.
Syntax
cd [<dir>]
Arguments
• <dir>
(optional) Specifies a full or relative directory path for QuestaSim to use as the local
directory. If you do not specify a directory, the command changes to your home directory.

88 ModelSim Reference Manual, v10.1c

Commands
change

change
This command modifies the value of a:
• VHDL constant, generic, or variable
• Verilog register or variable
Syntax
change <variable> <value>
Arguments
• <variable>
(required) A string that specifies the name of an object. The name can be a full hierarchical
name or a relative name, where a relative name is relative to the current environment.
Wildcards are not permitted.
The following sections list supported objects:
• VHDL
o Scalar variable, constant, or generics of all types except FILE.
Generates a warning when changing a VHDL constant or generic. You can suppress
this warning by setting the TCL variable WarnConstantChange to 0 or in the [vsim]
section of the modelsim.ini file.
o Scalar subelement of composite variable, constant, and generic of all types except
FILE.
o One-dimensional array of enumerated character types, including slices.
o Access type. An access type pointer can be set to "null"; the value that an access type
points to can be changed as specified above.
• Verilog
o Parameter.
o Register or memory.
o Integer, real, realtime, time, and local variables in tasks and functions.
o Subelements of register, integer, real, realtime, and time multi-dimensional arrays
(all dimensions must be specified).
o Bit-selects and part-selects of the above except for objects whose basic type is real.
The name can be a full hierarchical name or a relative name. A relative name is relative to
the current environment. Wildcards cannot be used.

ModelSim Reference Manual, v10.1c 89

Commands
change

• <value>
(required) Defines a value for <variable>. The specified value must be appropriate for the
type of the variable. You must place <value> within quotation marks (“ “) or curly braces
({ }) if it contains spaces .
Note
The initial type of <variable> determines the type of value that it can be given. For
example, if <variable> is initially equal to 3.14 then only real values can be set on it.
Also note that changing the value of a parameter or generic will not modify any design
elements that depended on the parameter or generic during elaboration (for example,
sizes of arrays).

Examples
• Change the value of the variable count to the hexadecimal value FFFF.
change count 16#FFFF

• Change the value of the element of rega that is specified by the index (i.e., 16).
change {rega[16]} 0

• Change the value of the set of elements of foo that is specified by the slice (i.e., 20:22).
change {foo[20:22]} 011

• Set the Verilog register file_name to "test2.txt". Note that the quote marks are escaped
with ’\’.
change file_name \"test2.txt\"

• Set the time value of the mytimegeneric variable to 500 ps. The time value is enclosed
by curly braces (or quotation marks) because of the space between the value and the
units.
change mytimegeneric {500 ps}

Related Topics
• force

90 ModelSim Reference Manual, v10.1c

Commands
classinfo

classinfo
This command allows the user to access information about class types and instances available in
the simulation. You can view, find and report statistics about class instances.
The following table summarizes the class viewing options:
Command Description
classinfo find Reports on the current state of a particular class instance, whether
it exists, has been destroyed, or has not yet been created.
classinfo instances Displays the list of class items in the specified class.
classinfo report Prints a detailed report of a set of classes and their usage.
classinfo stats Displays statistics about the number of class types and instances.
classinfo types Displays the list of classes that match or do not match the
specified pattern.

Syntax
classinfo find [-tcl] [ -o <outfile>] class-instance-name
classinfo instances [-tcl] [-o <outfile>] classname
classinfo report [-c [fntpc]] [-m <maxout>] [-o <outfile>] [-sort [a | d][f | n | t | p | c]] [-tcl] [-z]
classinfo stats [-tcl] [-o <outfile>]
classinfo types [-tcl] [-n] [-o <outfile>] [-x] pattern
Arguments
• -c [fntpc]
Display the report columns in the specified order in a report. The default is to display all
columns in the following order: Full Path, Class Name, Total, Peak, Current. You can
specify one or more columns in any order.
f — The Full Path column displays the full relative path name.
n — The Class Name column displays the name of the class instance.
t — The Total column displays the total number of instances of the named class.
p — The Peak column displays the maximum number of instances of the named class
that existed simultanously at any time in the simulation.
c — The Current column displays the current number of instances of the named class.
• class-instance-name
(required for classinfo find) Name of the class item in the following format @<name>@#.
• classname
(required for classinfo types) Name of the class or the full path of the class type.

ModelSim Reference Manual, v10.1c 91

Commands
classinfo

• -m <maxout>
Display the specified number of lines of the report.
<maxout> — Any non-negative integer.
• -n
Returns class names only. Does not include the path unless required to resolve name
ambiguity.
• -o <outfile>
Sends the results of the command to <outfile> instead of the transcript.
<outfile> — Specifies the name of the file where the output will be written.
• pattern
A standard TCL glob expression used as a search string.
• -sort [a | d][f | n | t | p | c]
Specifies whether the report information is sorted in ascending or descending order and
which column to sort by. Only one column can be specified for sorting.
a — Sort the entries in ascending order.
d — Sort the entries in descending order.
f — Sort by the Full Path column
n— Sort by the Class Name column
t — Sort by the Total column
p — Sort by the Peak column
c — Sort by the Current column
• -tcl
Returns a tcl list instead of formatted output.
• -x
Display classes that do not match the pattern.
• -z
Remove all items from the report with a total instance count of zero.
Example
• List the full path of the class types that do not match the pattern *uvm*.
vsim> classinfo types -x *uvm*

Returns:
# /environment_pkg::test_predictor
# /environment_pkg::threaded_scoreboard
# /mem_agent_pkg::mem_agent

92 ModelSim Reference Manual, v10.1c

Commands
classinfo

# /mem_agent_pkg::mem_config
# /mem_agent_pkg::mem_driver

• Display the current number of class types, the maximum number, peak number and
current number of all class instances.
vsim> classinfo stats

Returns:
# class type count 451
# class instance count (total) 2070
# class instance count (peak) 1075
# class instance count (current) 1058

• List the current instances for the class type mem_item.

vsim> classinfo instances mem_item

Returns:
# @mem_item@140
# @mem_item@139
# @mem_item@138
# @mem_item@80
# @mem_item@76
# @mem_item@72
# @mem_item@68
# @mem_item@64

• Create a report of all class instances in descending order in the Total column. Print the
Class Names, Total, Peak, and Current columns. List only the first six lines of that
report.
vsim> classinfo report -s dt -c ntpc -m 6

Returns:
# Class Name Total Peak Current
# uvm_pool__11 318 315 315
# uvm_event 286 55 52
# uvm_callback_iter__1 273 3 2
# uvm_queue__3 197 13 10
# uvm_object_string_pool__1 175 60 58
# mem_item 140 25 23

• Find the class instance @mem_item@87

VSIM> classinfo find @mem_item@87

Returns:
# @mem_item@87 has been destroyed

• Find the class instance @mem_item@200

VSIM> classinfo find @mem_item@200

ModelSim Reference Manual, v10.1c 93

Commands
classinfo

Returns:
# @mem_item@200 not yet created

Related Topics
• ClassDebug modelsim.ini variable
• vsim -classdebug

94 ModelSim Reference Manual, v10.1c

Commands
configure

configure
The configure command invokes the List or Wave widget configure command for the current
default List or Wave window.
To change the default window, use the view command.
Some arguments to this command are order-dependent. Please read through the arguments for
further information.
Syntax
configure list | wave [<option> <value>]

---- List Window Arguments

[-delta [all | collapse | events | none]] [-gateduration [<duration_open>]]
[-gateexpr [<expression>]] [-usegating [off | on]] [-strobeperiod [<period>[<unit>]]]
[-strobestart [<start_time>[<unit>]]] [-usesignaltriggers [0 | 1]] [-usestrobe [0 | 1]]

---- Wave Window Arguments

[-childrowmargin [<pixels>]] [-cursorlockcolor [<color>]] [-gridauto [off | on]]
[-gridcolor [<color>]][-griddelta [<pixels>]] [-gridoffset [<time>[<unit>]]]
[-gridperiod [<time>[<unit>]]] [-namecolwidth [<width>]] [-rowmargin [<pixels>]]
[-signalnamewidth [<value>]] [-timecolor [<color>]] [-timeline [0 | 1]]
[-timelineunits [fs | ps | ns | us | ms | sec | min | hr]] [-valuecolwidth [<width>]]
[-vectorcolor [<color>]] [-waveselectcolor [<color>]] [-waveselectenable [0 | 1]]
Description
The command works in three modes:
• without options or values it returns a list of all attributes and their current values
• with just an option argument (without a value) it returns the current value of that
attribute
• with one or more option-value pairs it changes the values of the specified attributes to
the new values
The returned information has five fields for each attribute: the command-line switch, the Tk
widget resource name, the Tk class name, the default value, and the current value.
Arguments
• list | wave
(required) Controls the widget to configure. Must be specified as the first argument to the
configure command.
list — Specifies the List widget.
wave — Specifies the Wave widget.

ModelSim Reference Manual, v10.1c 95

Commands
configure

• <option> <value>
-bg <color> — (optional) Specifies the window background color.
-fg <color> — (optional) Specifies the window foreground color.
-selectbackground <color> — (optional) Specifies the window background color when
selected.
-selectforeground <color> — (optional) Specifies the window foreground color when
selected.
-font <font> — (optional) Specifies the font used in the widget.
-height <pixels> — (optional) Specifies the height in pixels of each row. .
Arguments, List window only
• -delta [all | collapse | events | none]
(optional) Specifies how information is displayed in the delta column. To use -delta,
-usesignaltriggers must be set to 1 (on).
all — Displays a new line for each time step on which objects change.
collapse — Displays the final value for each time step.
events — Displays an "event" column rather than a "delta" column and sorts List
window data by event.
none — Turns off the display of the delta column.
• -gateduration [<duration_open>]
(optional) Extends gating beyond the back edge (the last list row in which the expression
evaluates to true). The duration for gating to remain open beyond when -gateexpr (below)
becomes false, expressed in x number of timescale units. The default value for normal
synchronous gating is zero. If -gateduration is set to a non-zero value, a simulation value
will be displayed after the gate expression becomes false (if you don’t want the values
displayed, set -gateduration to zero).
<duration_open> — Any non-negative integer where the default is 0 (values are not
displayed).
• -gateexpr [<expression>]
(optional) Specifies the expression for trigger gating. (Use the -usegating argument to
enable trigger gating.) The expression is evaluated when the List window would normally
have displayed a row of data.
<expression> — An expression.
• -usegating [off | on]
(optional) Enables triggers to be gated on or off by an overriding expression. (Use the
-gatexpr argument to specify the expression.) Refer to “Using Gating Expressions to
Control Triggering” for additional information on using gating with triggers.
off — (default) Triggers are gated off (a value of 0).

96 ModelSim Reference Manual, v10.1c

Commands
configure

on — Triggers are gated on (a value of 1).

• -strobeperiod [<period>[<unit>]]
(optional) Specifies the period of the list strobe.
<period> — Any non-negative integer.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <delay> and <unit>
within curly braces ({}).
• -strobestart [<start_time>[<unit>]]
(optional) Specifies the start time of the list strobe.
<start_time> — Any non-negative integer.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <delay> and <unit>
within curly braces ({}).
• -usesignaltriggers [0 | 1]
(optional) Specifies whether or not signals are to be used as triggers.
0 — Signals are not used as triggers
1 — Signals are used as triggers
• -usestrobe [0 | 1]
(optional) Specifies whether or not a strobe is used as a trigger.
0 — Strobe is not used to trigger.
1 — Strobe is used to trigger.
Arguments, Wave window only
• -childrowmargin [<pixels>]
(optional) Specifies the distance in pixels between child signals. Related Tcl variable is
PrefWave(childRowMargin).
<pixels> — Any non-negative integer where the default is 2.
• -cursorlockcolor [<color>]
(optional) Specifies the color of a locked cursor. Related Tcl variable is
PrefWave(cursorLockColor).
<color> — Any Tcl color where the default is red.
• -gridauto [off | on]
(optional) Controls the grid period when in simulation time mode.
off — (default) user-specified grid period is used.

ModelSim Reference Manual, v10.1c 97

Commands
configure

on — grid period is determined by the major tick marks in the time line.
• -gridcolor [<color>]
(optional) Specifies the background grid color. Related Tcl variable is
PrefWave(gridColor).
<color> — Any color where the default is grey50.
• -griddelta [<pixels>]
(optional) Specifies the closest (in pixels) two grid lines can be drawn before intermediate
lines will be removed. Related Tcl variable is PrefWave(gridDelta).
<pixels> — Any non-negative integer where the default is 40.
• -gridoffset [<time>[<unit>]]
(optional) Specifies the time (in user time units) of the first grid line. Related Tcl variable is
PrefWave(gridOffset).
<time> — Any non-negative integer where the default is 0.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <delay> and <unit>
within curly braces ({}).
• -gridperiod [<time>[<unit>]]
(optional) Specifies the time (in user time units) between subsequent grid lines. Related Tcl
variable is PrefWave(gridPeriod).
<time> — Any non-negative integer where the default is 1.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <delay> and <unit>
within curly braces ({}).
• -namecolwidth [<width>]
(optional) Specifies the width of the name column in pixels. Related Tcl variable is
PrefWave(nameColWidth).
<width> — Any non-negative integer where the default is 150.
• -rowmargin [<pixels>]
(optional) Specifies the distance between top-level signals in pixels. Related Tcl variable is
PrefWave(rowMargin).
<pixels> — Any non-negative integer where the default is 4.
• -signalnamewidth [<value>]
(optional) Controls the number of hierarchical regions displayed as part of a signal name
shown in the pathname pane. Related Tcl variable is PrefWave(SignalNameWidth). Can
also be set with the WaveSignalNameWidth variable in the modelsim.ini file.

98 ModelSim Reference Manual, v10.1c

Commands
configure

<value> — Any non-negative integer where the default is 0 (display the full path. For
example,1 displays only the leaf path element, 2 displays the last two path elements,
and so on.
• -timecolor [<color>]
(optional) Specifies the time axis color. Related Tcl variable is PrefWave(timeColor).
<color> — Any color where the default is green.
• -timeline [0 | 1]
(optional) Specifies whether the horizontal axis displays simulation time or grid period
count. Related Tcl variable is PrefWave(timeline).
0 — (default) Simulation time is displayed.
1 — Grid period count is displayed.
• -timelineunits [fs | ps | ns | us | ms | sec | min | hr]
(optional) Specifies units for timeline display. Does not affect the currently-defined
simulation time.
fs — femtosecond (10-15 seconds)
ps — picosecond (10-12 seconds)
ns — nanosecond (10-9 seconds) (default)
us — microsecond (10-6 seconds)
ms — millisecond (10-3 seconds)
sec — second
min — minute (60 seconds)
hr — hour (3600 seconds)
• -valuecolwidth [<width>]
(optional) Specifies the width of the value column, in pixels. Related Tcl variable is
PrefWave(valueColWidth).
<width> — Any non-negative integer where the default is 100.
• -vectorcolor [<color>]
(optional) Specifies the vector waveform color. Default is #b3ffb3. Related Tcl variable is
PrefWave(vectorColor).
<color> — Any color where the default is #b3ffb3.
• -waveselectcolor [<color>]
(optional) Specifies the background highlight color of a selected waveform. Related Tcl
variable is PrefWave(waveSelectColor).
<color> — Any color where the default is grey30.

ModelSim Reference Manual, v10.1c 99

Commands
configure

• -waveselectenable [0 | 1]
(optional) Specifies whether the waveform background highlights when an object is
selected. Related Tcl variable is PrefWave(waveSelectEnabled).
0 — (default) Highlighting is disabled.
1 — Highlighting is enabled.
There are more options than are listed here. See the output of a configure list or configure wave
command for all options.
Examples
• Display the current value of the strobeperiod attribute.
config list -strobeperiod

• Set the period of the list strobe and turns it on.

config list -strobeperiod {50 ns} -strobestart 0 -usestrobe 1

• Set the wave vector color to blue.

config wave -vectorcolor blue

• Set the display in the current Wave window to show only the leaf path of each signal.
config wave -signalnamewidth 1

Related Topics
• view
• Simulator GUI Preferences

100 ModelSim Reference Manual, v10.1c

Commands
dataset alias

dataset alias
This command maps an alternate name (alias) to an open dataset. A dataset can have any
Commands

number of aliases, but all dataset names and aliases must be unique even when more than one
dataset is open. Aliases are not saved to the .wlf file and must be remapped if the dataset is
closed and then re-opened.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
dataset alias <dataset_name> [<alias_name>]
Arguments
• <dataset_name>
(required) Specifies a dataset name or currently assigned dataset alias. Must be specified as
the first argument to the dataset alias command. Returns a list of all aliases mapped to the
specified dataset file when specified without <dataset_alias>.
• <alias_name>
(optional) Specifies string to assign to the dataset as an alias. Wildcard characters are
permitted.
Examples
Assign the alias name “bar” to the dataset named “gold.”
dataset alias gold bar

Related Topics
• dataset clear • dataset open
• dataset close • dataset rename
• dataset config • dataset restart
• dataset info • dataset save
• dataset list • dataset snapshot

ModelSim Reference Manual, v10.1c 101

Commands
dataset clear

dataset clear
This command applies only to WLF based simulation datasets. It has no effect on coverage
(UCDB) datasets. All event data is removed from the current simulation WLF file, while
retaining all currently logged signals. Subsequent run commands will continue to accumulate
data in the WLF file.
If the command is executed when no design is loaded then the error: “Dataset not found:sim” is
returned. If the command is executed when a design is loaded, then the “sim:” dataset is cleared,
irrespective of which dataset is currently set. Clearing the dataset will clear any open wave
window based on the “sim:”.
Syntax
dataset clear
Examples
Clear data in the WLF file from time 0ns to 100000ns, then log data into the WLF file from
time 100000ns to 200000ns.
add wave *
run 100000ns
dataset clear
run 100000ns

Related Topics
• dataset alias • dataset rename
• dataset close • dataset restart
• dataset config • dataset save
• dataset info • dataset snapshot
• dataset list • log
• dataset open • Recording Simulation Results With
Datasets

102 ModelSim Reference Manual, v10.1c

Commands
dataset close

dataset close
This command closes an active dataset. To open a dataset, use the dataset open command.
Syntax
dataset close {<dataset_name> | -all}
Arguments
• <dataset_name> | -all
(required) Closes active dataset(s).
<dataset_name> — Specifies the name of the dataset or alias you wish to close.
-all — Closes all open datasets and the simulation.
Related Topics
• dataset alias • dataset open
• dataset clear • dataset rename
• dataset config • dataset restart
• dataset info • dataset save
• dataset list • dataset snapshot

ModelSim Reference Manual, v10.1c 103

Commands
dataset config

dataset config
This command configures WLF parameters for an open dataset and all aliases mapped to that
dataset. It has no effect on coverage datasets (UCDB).
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
dataset config <dataset_name> [-wlfcachesize [<n>]] [-wlfdeleteonquit [0 | 1]] [-wlfopt [0 | 1]]
Arguments
• <dataset_name>
(required) Specifies a open dataset or dataset alias you wish to configure. Must be specified
as the first argument to the dataset config command.
• -wlfcachesize [<n>]
(optional) Sets the size, in megabytes, of the WLF reader cache. Does not affect the WLF
write cache.
<n> — Any non-negative integer, in MB where the default is 256.
If you do not specify a value for <n>, this switch returns the size, in megabytes, of the WLF
reader cache.
• -wlfdeleteonquit [0 | 1]
(optional) Deletes the WLF file automatically when the simulation exits. Valid for the
current simulation dataset only.
0 — Disabled (default)
1 — Enabled
If you do not specify an argument, this switch returns the current setting for the switch.
• -wlfopt [0 | 1]
(optional) Optimizes the display of waveforms in the Wave window.
0 — Disabled
1 — Enabled (default)
If you do not specify an argument, this switch returns the current setting for the switch.
Examples
Set the size of the WLF reader cache for the dataset “gold” to 512 MB.
dataset config gold -wlfcachesize 512

104 ModelSim Reference Manual, v10.1c

Commands
dataset config

Related Topics
• dataset alias • dataset rename
• dataset clear • dataset restart
• dataset close • dataset save
• dataset config • dataset snapshot
• dataset info • WLF File Parameter Overview
• dataset list • vsim
• dataset open

ModelSim Reference Manual, v10.1c 105

Commands
dataset current

dataset current
This command activates the specified dataset and sets the GUI context to the last selected
context of the specified dataset. All context dependent GUI data is updated and all context
dependent CLI commands start working with respect to the new context.
Syntax
dataset current [<dataset_name>]
Arguments
• <dataset_name>
(optional) Specifies the dataset name or dataset alias you want to activate. If no dataset
name or alias is specified, the command returns the name of the currently active dataset.
Related Topics
• dataset alias • dataset rename
• dataset clear • dataset restart
• dataset close • dataset save
• dataset info • dataset snapshot
• dataset list • WLF File Parameter Overview
• dataset open • vsim

106 ModelSim Reference Manual, v10.1c

Commands
dataset info

dataset info
This command reports a variety of information about a dataset.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
dataset info {name | file | exists} <dataset_name>
Arguments
• {name | file | exists}
(required) Identifies what type of information you want reported.
Only one option per command is allowed. The current options include:
name — Returns the name of the dataset. Useful for identifying the real dataset name of
an alias.
file — Returns the name of the WLF file or UCDB file associated with the dataset.
exists — Returns "1" if the dataset is currently open, "0" if it does not.
Must be specified as the first argument to the dataset info command.
• <dataset_name>
(optional) Specifies the name of the dataset or alias for which you want information. If you
do not specify a dataset name, ModelSim uses the dataset of the current environment.
Related Topics
• dataset alias • dataset rename
• dataset clear • dataset restart
• dataset close • dataset save
• dataset config • dataset snapshot
• dataset list • environment
• dataset open

ModelSim Reference Manual, v10.1c 107

Commands
dataset list

dataset list
This command lists all active datasets.
Syntax
dataset list [-long]
Arguments
• -long
(optional) Lists the dataset name followed by the .wlf file to which the dataset name is
mapped.
Related Topics
• dataset alias • dataset open
• dataset clear • dataset rename
• dataset close • dataset restart
• dataset config • dataset save
• dataset info • dataset snapshot

108 ModelSim Reference Manual, v10.1c

Commands
dataset open

dataset open
This command opens a WLF file (either the currently running vsim.wlf or a saved WLF file)
and/or UCDB file (representing coverage data) and assigns it the logical name that you specify.
The file may be the WLF file for a currently running simulation. To close a dataset, use dataset
close.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
dataset open <file_name> [<dataset_name>]
Arguments
• <file_name>
(required) Specifies the WLF file or UCDB file to open as a view-mode dataset. Must be
specified as the first argument to the dataset open command. Specify vsim.wlf to open the
currently running WLF file.
• <dataset_name>
(optional) Specifies a name for the open dataset. This is a name that will identify the dataset
in the current session. By default the dataset prefix will be the name of the specified WLF or
UCDB file.
Examples
Open the dataset file last.wlf and assign it the name test.
dataset open last.wlf test

Related Topics
• dataset alias • dataset list
• dataset clear • dataset rename
• dataset close • dataset restart
• dataset config • dataset save
• dataset info • dataset snapshot
• vsim -view option

ModelSim Reference Manual, v10.1c 109

Commands
dataset rename

dataset rename
This command changes the name of a dataset to the new name you specify.
Arguments to this command are order dependent. Follow the order specified in the Syntax
section.
Syntax
dataset rename <dataset_name> <new_dataset_name>
Arguments
• <dataset_name>
Specifies the existing name of the dataset.
• <new_dataset_name>
Specifies the new name for the dataset.
Examples
Rename the dataset file "test" to "test2".
dataset rename test test2

Related Topics
• dataset alias • dataset list
• dataset clear • dataset open
• dataset close • dataset restart
• dataset config • dataset save
• dataset info • dataset snapshot

110 ModelSim Reference Manual, v10.1c

Commands
dataset restart

dataset restart
This command unloads the specified dataset or currently active dataset and reloads the dataset
using the same dataset name. The contents of Wave and other coverage windows are restored
for UCDB datasets after a reload.
Syntax
dataset restart [<file_name>]
Arguments
• <file_name>
(optional) Specifies the WLF or UCDB file to open as a view-mode or coverage mode
dataset. If <filename> is not specified, the currently active dataset is restarted.
Related Topics
• dataset alias • dataset list
• dataset clear • dataset open
• dataset close • dataset rename
• dataset config • dataset save
• dataset info • dataset snapshot

ModelSim Reference Manual, v10.1c 111

Commands
dataset save

dataset save
This command writes data from the current simulation to the specified file. This lets you save
simulation data while the simulation is still in progress.
Arguments to this command are order dependent. Follow the order specified in the Syntax
section.
Syntax
dataset save <dataset_name> <file_name>
Arguments
• <dataset_name>
(required) Specifies the name of the dataset you want to save.
• <file_name>
(required) Specifies the name of the file to save.
Examples
Save all current log data in the sim dataset to the file gold.wlf.
dataset save sim gold.wlf

Related Topics
• dataset alias • dataset list
• dataset clear • dataset open
• dataset close • dataset rename
• dataset config • dataset restart
• dataset info • dataset snapshot

112 ModelSim Reference Manual, v10.1c

Commands
dataset snapshot

dataset snapshot
This command saves data from the current WLF file (vsim.wlf by default) at a specified interval.
It provides you with sequential or cumulative "snapshots" of your simulation data. This
command does not apply to coverage datasets (UCDB).
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
dataset snapshot [-dir <directory>] [-disable] [-enable] [-file <file_name>]
[-filemode {overwrite | increment}] [-mode {cumulative | sequential}] [-report] [-reset]
{-size <file_size> | -time <n> [<unit>]}
Arguments
• -dir <directory>
(optional) Specifies a directory into which the files should be saved. Either absolute or
relative paths may be used. Default is to save to the current working directory.
• -disable
(optional) Turns snapshotting off. All dataset snapshot settings from the current simulation
are stored in memory. All other options are ignored after you specify -disable.
• -enable
(optional) Turns snapshotting on. Restores dataset snapshot settings from memory or from a
saved dataset. (default)
• -file <file_name>
(optional) Specifies the name of the file to save snapshot data.
<file_name> — A specified file name where the default is vsim_snapshot.wlf. The
suffix .wlf will be appended to specified filename and, possibly, an incrementing
suffix.
When the duration of the simulation run is not a multiple of the interval specified by -size or
-time, the incomplete portion is saved in the file vsim.wlf.
• -filemode {overwrite | increment}
(optional) Specifies whether to overwrite the snapshot file each time a snapshot occurs.
overwrite — (default)
increment — A new file is created for each snapshot. An incrementing suffix (1 to n) is
added to each new file (for example, vsim_snapshot_1.wlf).
• -mode {cumulative | sequential}
(optional) Specifies whether to keep all data from the time signals are first logged.
cumulative — (default)
sequential — The current WLF file is cleared every time a snapshot is taken.

ModelSim Reference Manual, v10.1c 113

Commands
dataset snapshot

• -report
(optional) Lists current snapshot settings in the Transcript window. All other options are
ignored if you specify -report.
• -reset
(optional) Resets values back to defaults. The behavior is to reset to the default, then apply
the remainder of the arguments on the command line. See examples below. If specified by
itself without any other arguments, -reset disables dataset snapshot and resets the values.
• -size <file_size>
(Required if -time is not specified.) Specifies that a snapshot occurs based on WLF file size.
Must be specified as the final argument to the dataset snapshot command.
<file_size> — Size of WLF file in MB.
• -time <n> [<unit>]
(Required if -size is not specified.) Specifies that a snapshot occurs based on simulation
time. Must be specified as the final argument to the dataset snapshot command.
<n> — Any positive integer.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <limit> and <unit>
within curly braces ({}).
Examples
• Create the file vsim_snapshot_<n>.wlf that is written to every time the current WLF file
reaches a multiple of 10 MB (i.e., at 10 MB, 20 MB, 30 MB, etc.).
dataset snapshot -size 10

• Similar to the previous example, but in this case the current WLF file is cleared every
time it reaches 10 MB.
dataset snapshot -size 10 -mode sequential

• Assuming simulator time units are ps, this command saves a file called gold_<n>.wlf
every 1000000 ps. If you run the simulation for 3000000 ps, three files are saved:
gold_1.wlf with data from 0 to 1000000 ps, gold_2.wlf with data from 1000000 to
2000000, and gold_3.wlf with data from 2000000 to 3000000.
dataset snapshot -time 1000000 -file gold.wlf -mode sequential
-filemode increment

Because this example sets the time interval to 1000000 ps, if you run the simulation for
3500000 ps, a file containing the data from 3000000 to 3500000 ps is saved as vsim.wlf
(default).
• Enable snapshotting with time=10000 and default mode (cumulative) and default
filemode (overwrite).

114 ModelSim Reference Manual, v10.1c

Commands
dataset snapshot

dataset snapshot -reset -time 10000

Related Topics
• dataset alias • dataset list
• dataset clear • dataset open
• dataset close • dataset rename
• dataset config • dataset restart
• dataset info • dataset save

ModelSim Reference Manual, v10.1c 115

Commands
delete

delete
This command removes objects from either the List or Wave window. Arguments to this
command are order dependent.
Syntax
delete list [-window <wname>] <object_name>
delete wave [-window <wname>] <object_name>
Arguments
• list
Specifies the target is a list window.
• wave
Specifies the target is a wave window.
• -window <wname>
(optional) Specifies the name of the List or Wave window to target for the delete command.
(The view command allows you to create more than one List or Wave window.) If no
window is specified, the default window is used; the default window is determined by the
most recent invocation of the view command and has “ - Default” appended to the name.
• <object_name>...
(required) Specifies the name of an object. Must match an object name used in an add list or
add wave command. Multiple object names are specified as a space separated list. Wildcard
characters are allowed. Must be specified as the final argument to the delete list and delete
wave commands.
Examples
• Remove the object vec2 from the list2 window.
delete list -window list2 vec2

• Remove all objects beginning with the string /test from the Wave window.
delete wave /test*

Related Topics
• add list • Wildcard Characters
• add wave

116 ModelSim Reference Manual, v10.1c

Commands
describe

describe
This command displays information about the following types of simulation objects and design
regions in the Transcript window:
• VHDL — signals, variables, and constants
• Verilog — nets and registers
• Design region
VHDL signals Verilog nets and registers can be specified as hierarchical names.
Syntax
describe <name>...
Arguments
• <name>...
(required) The name of an HDL object for which you want a description. Multiple object
names are specified as a space separated list. Wildcard characters are allowed. HDL object
names can be relative or full hierarchical names.
Examples
• Print the types of the three specified signals.
describe clk prw prdy

Related Topics
• add list • Wildcard Characters
• add wave

ModelSim Reference Manual, v10.1c 117

Commands
disablebp

disablebp
This command turns off breakpoints and when commands. To turn on breakpoints or when
commands again, use the enablebp command.
Syntax
disablebp [<id#> | <label>]
Arguments
• <id#>
(optional) Specifies the ID number of a breakpoint or when statement to disable.
• <label>
(optional) Specifies the label name of a breakpoint or when statement to disable.
If you do not specify either of these arguments, all breakpoints and when statements are
disabled.

Use the bp command with no arguments to find labels and ID numbers for all breakpoints in the
current simulation. Use the when command with no arguments to find labels and ID numbers of
all when statements in the current simulation.

Note
Id numbers for breakpoints and when statements are assigned from the same pool. Even if
you have not specified a given id number for a breakpoint, that number may still be used
for a when command.

Related Topics
• bd • onbreak
• bp • resume
• enablebp • when

118 ModelSim Reference Manual, v10.1c

Commands
do

do
This command executes the commands contained in a macro file.
A macro file can have any name and extension. An error encountered during the execution of a
macro file causes its execution to be interrupted, unless an onerror command or the
OnErrorDefaultAction Tcl variable is specified with the resume command. The onbreak
command is used to take action with source code breakpoint cases.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
do <filename> [<parameter_value>...]
Arguments
• <filename>
(required) Specifies the name of the macro file to be executed. The name can be a pathname
or a relative file name. Pathnames are relative to the current working directory. Must be
specified as the first argument to the do command.
If the do command is executed from another macro file, pathnames are relative to the
directory of the calling macro file. This allows groups of macro files to be stored in a
separate sub-directory.
• <parameter_value>...
(optional) Specifies values that are to be passed to the corresponding parameters $1 through
$9 in the macro file. Multiple parameter values must be separated by spaces.
If you want to make the parameters optional (for example, specify fewer parameter values
than the number of parameters actually used in the macro), you must use the argc simulator
state variable in the macro. Refer to “Making Macro Parameters Optional”.
Note
While there is no limit on the number of parameters that can be passed to macros, only
nine values are visible at one time. Use the shift command to see the other parameters.

Examples
• Execute the file macros/stimulus and pass the parameter value 100 to $1 in the macro
file.
do macros/stimulus 100

Where the macro file testfile contains the line

bp $1 $2

place a breakpoint in the source file named design.vhd at line 127.

ModelSim Reference Manual, v10.1c 119

Commands
do

do testfile design.vhd 127

Related Topics
• Tcl and Macros (DO Files) • DOPATH variable
• Modes of Operation • Saving a Transcript File as a Macro (DO
• Using a Startup File file)

120 ModelSim Reference Manual, v10.1c

Commands
drivers

drivers
This command displays the names and strength of all drivers of the specified object.
The driver list is expressed relative to the top-most design signal/net connected to the specified
object. If the object is a record or array, each sub-element is displayed individually.
The output from the drivers command, which is displayed in the Transcript window as a
hypertext link, allowing you to right-click to open a drop-down menu and quickly add signals to
various windows. It includes a "View Declaration" item to open the source definition of the
signal.

Figure 2-1. drivers Command Results in Transcript

Syntax
drivers <object_name> [-source]
Arguments
• <object_name>
(required) Specifies the name of the signal or net whose drivers are to be shown. All signal
or net types are valid. Multiple names and wildcards are accepted.
• -source
(optional) Returns the source file name and line number for each driver of the specified
signal or net. If the source location cannot be determined, the value n/a is returned for that
driver.
Example
drivers /top/dut/pkt_cnt(4)
# Drivers for /top/dut/pkt_cnt(4):
# St0 : Net /top/dut/pkt_cnt[4]
# St0 : Driver /top/dut/pkt_counter/#IMPLICIT-WIRE(cnt_out)#6

In some cases, the output may supply a strength value similar to 630 or 52x, which indicates an
ambiguous verilog strength.

ModelSim Reference Manual, v10.1c 121

Commands
drivers

Related Topics
• readers
• Verilog Language Reference Manual Std
1365-2005 section 7.10.2 "Ambiguous
strengths: sources and combinations"

122 ModelSim Reference Manual, v10.1c

Commands
dumplog64

dumplog64
This command dumps the contents of the specified WLF file in a readable format to stdout.
The WLF file cannot be opened for writing in a simulation when you use this command. This
command cannot be used in a DO file.
Syntax
dumplog64 <filename>
Arguments
• <filename>
(required) The name of the WLF file to be read.

ModelSim Reference Manual, v10.1c 123

Commands
echo

echo
This command displays a specified message in the Transcript window.
Syntax
echo [<text_string>]
Arguments
• <text_string>
(required) Specifies the message text to be displayed. If the text string is surrounded by
quotes, blank spaces are displayed as entered. If quotes are omitted, two or more adjacent
blank spaces are compressed into one space.
Examples
• If the current time is 1000 ns, this command:
echo “The time is $now ns.”

returns the message:

The time is 1000 ns.

• If the quotes are omitted:

echo The time is $now ns.

all blank spaces of two or more are compressed into one space.
The time is $now ns.”

• echo can also use command substitution, such as:

echo The hex value of counter is [examine -hex counter].

If the current value of counter is 21 (15 hex), this command returns:

The hex value of counter is 15.

124 ModelSim Reference Manual, v10.1c

Commands
edit

edit
This command invokes the editor specified by the EDITOR environment variable. By default,
the specified filename will open in the Source window.
Syntax
edit [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the file to edit. If the <filename> argument is omitted, the
editor opens the current source file. If you specify a non-existent filename, it will open a
new file. Either absolute or relative paths may be used.
Related Topics
• notepad
• EDITOR environment variable

ModelSim Reference Manual, v10.1c 125

Commands
enablebp

enablebp
This command turns on breakpoints and when commands that were previously disabled.
Syntax
enablebp [<id#> | <label>]
Arguments
• <id#>
(optional) Specifies a breakpoint ID number or when statement to enable.
• <label>
(optional) Specifies the label name of a breakpoint or when statement to enable.
If you do not specify either of these arguments, all breakpoints are enabled.

Use the bp command with no arguments to find labels and ID numbers for all breakpoints in the
current simulation. Use the when command with no arguments to find labels and ID numbers of
all when statements in the current simulation.

Related Topics
• bd • onbreak
• bp • resume
• disablebp • when

126 ModelSim Reference Manual, v10.1c

Commands
encoding

encoding
This command translates between the 16-bit Unicode characters used in Tcl strings and a named
encoding, such as Shift-JIS. There are four encoding commands used to work with the encoding
of your character representations in the GUI.
• encoding convertfrom — Convert a string from the named encoding to Unicode.
• encoding convertto — Convert a string to the named encoding from Unicode.
• encoding names — Returns a list of all valid encoding names.
• encoding system — Changes the current system encoding to a named encoding. If a new
encoding is omitted the command returns the current system encoding. The system
encoding is used whenever Tcl passes strings to system calls.
Syntax
encoding convertfrom <encoding_name> <string>
encoding convertto <encoding_name> <string>
encoding names
encoding system <encoding_name>
Arguments
• string — Specifies a string to be converted.
• encoding_name — The name of the encoding to use.

ModelSim Reference Manual, v10.1c 127

Commands
environment

environment
This command has two forms, environment and env. It allows you to display or change the
current dataset and region/signal environment.
Syntax
environment [-dataset | -nodataset] [<pathname> | -forward | -back]
Arguments
• -dataset
(optional) Displays the specified environment pathname with a dataset prefix. Dataset
prefixes are displayed by default.
• -nodataset
(optional) Displays the specified environment pathname without a dataset prefix.
• <pathname>
(optional) Specifies a new pathname for the region/signal environment.
If omitted the command causes the pathname of the current region/signal environment to be
displayed.
• -forward
(optional) Displays the next environment in your history of visited environments.
• -back
(optional) Displays the previous environment in your history of visited environments.
Examples
• Display the pathname of the current region/signal environment.
env

• Change to another dataset but retain the currently selected context.

env test:

• Change all unlocked windows to the context "test:/top/foo".

env test:/top/foo

• Move down two levels in the design hierarchy.

env blk1/u2

• Move to the top level of the design hierarchy.

env /

128 ModelSim Reference Manual, v10.1c

Commands
environment

Related Topics
• Refer to Object Name Syntax for • Refer to Setting your Context by
information on specifying pathnames. Navigating Source Files for more
information about -forward and -back.

ModelSim Reference Manual, v10.1c 129

Commands
examine

examine
This command has two forms, examine and exa. It examines one or more objects and displays
current values (or the values at a specified previous time) in the Transcript window.
It can also compute the value of an expression of one or more objects.
The following objects can be examined:
• VHDL — signals, shared variables, process variables, constants, and generics
• Verilog — nets, registers, parameters, and variables
To display a previous value, specify the desired time using the -time option.
To compute an expression, use the -expr option. The -expr and the -time options may be used
together.
Virtual signals and functions may also be examined within the GUI (actual signals are
examined in the kernel).
The following rules are used by the examine command to locate an HDL object:
• If the name does not include a dataset name, then the current dataset is used.
• If the name does not start with a path separator, then the current context is used.
• If the name is a path separator followed by a name that is not the name of a top-level
design unit, then the first top-level design unit in the design is used.
• For a relative name containing a hierarchical path, if the first object name cannot be
found in the current context, then an upward search is done up to the top of the design
hierarchy to look for a matching object name.
• If no objects of the specified name can be found in the specified context, then an upward
search is done to look for a matching object in any visible enclosing scope up to an
instance boundary. If at least one match is found within a given context, no (more)
upward searching is done; therefore, some objects that may be visible from a given
context will not be found when wildcards are used if they are within a higher enclosing
scope.
• The wildcards '*' and '?' can be used at any level of a name except in the dataset name
and inside of a slice specification.
• A wildcard character will never match a path separator. For example, /dut/* will match
/dut/siga and /dut/clk. However, /dut* won’t match either of those.
See Design Object Names for more information on specifying names.
Syntax
examine <name>… [-delta <delta>] [-env <path>] [-event <time>] [-handle] {[-in] [-out]
[-inout] | [-ports]} [-internal] [-maxlen <integer>] [-expr <expression>] [-name]

130 ModelSim Reference Manual, v10.1c

Commands
examine

[-<radix_type>] [-radix <type>] [-radixenumnumeric | -radixenumsymbolic] [-showbase]

[-time <time>] [-value]
Arguments
• <name>…
(required except when specifying -expr.) Specifies the name of any HDL object.
All object types are allowed, except those of the type file. Multiple names and wildcards are
accepted. Spaces, square brackets, and extended identifiers require curly braces; see
examples below for more details. To examine a VHDL variable you can add a process label
to the name. For example, (make certain to use two underscore characters):
exa line__36/i

• -delta <delta>
(optional) Specifies a simulation cycle at the specified time step from which to fetch the
value, where the default is to use the last delta of the time step. You must log the objects to
be examined using the add list, add wave, or log command for the examine command to be
able return a value for a requested delta.
<delta> — Any non-negative integer.
• -env <path>
(optional) Specifies a path in which to look for an object name.
<path> — The specified path to a object.
• -event <time>
(optional) Specifies a simulation cycle at the specified event time from which to fetch the
value. The event <time> refers to the event time relative to events for all signals in the
objects dataset at the specified time. You must log the objects to be examined using the add
list, add wave, or log command for the examine command to be able return a value for a
requested event.
• -expr <expression>
(optional) Specifies an expression to be examined. You must log the expression using the
add list, add wave, or log command for the examine command to return a value for a
specified expression. The expression is evaluated at the current time simulation. If you also
specify the -time argument, the expression will be evaluated at the specified time. It is not
necessary to specify <name> when using this argument. See GUI_expression_format for the
format of the expression.
<expression> — Specifies an expression enclosed in braces ({}).
• -handle
(optional) Returns the memory address of the specified <name>. You can use this value as a
tag when analyzing the simulation. This value also appears as the title of a box in the Watch
window. This option will not return any value if you are in -view mode.

ModelSim Reference Manual, v10.1c 131

Commands
examine

• -in
(optional) Specifies that <name> include ports of mode IN.
• -out
(optional) Specifies that <name> include ports of mode OUT.
• -inout
(optional) Specifies that <name> include ports of mode INOUT.
• -internal
(optional) Specifies that <name> include internal (non-port) signals.
• -maxlen <integer>
(optional) Specifies the maximum number of characters in the output of the command.
<integer> — Any non-negative integer where 0 is unlimited.
• -ports
(optional) Specifies that <name> include all ports. Has the same effect as specifying -in,
-inout, and -out together.
• -name
(optional) Displays object name(s) and value(s). Related switch is -value.
• -<radix_type>
(optional) Specifies the radix type for the objects that follow in the command. Valid entries
(or any unique abbreviations) are: binary, ascii, unsigned, decimal, octal, hex, symbolic,
time, and default.
If no radix is specified for an enumerated type, the default radix is used. You can change the
default radix for the current simulation using the radix command. You can change the
default radix permanently by editing the DefaultRadix variable in the modelsim.ini file.
• -radix <type>
(optional) Specifies a user-defined radix. The -radix <type> switch can be used in place of
the -<radix_type> switch. For example, -radix hexadecimal is the same as -hex.
<type> — binary, ascii, unsigned, decimal, octal, hex, symbolic, time, and default.
This option overrides the global setting of the default radix (the DefaultRadix variable in the
modelsim.ini file).
• -radixenumnumeric
(optional) Causes Verilog and SystemC enums to be displayed as numbers (formatted by the
current radix). This overrides the default behavior of always showing enums symbolically.
• -radixenumsymbolic
(optional) Restores the default behavior of displaying Verilog and SystemC enums as
symbols by reversing the action of the -radixenumnumeric option.

132 ModelSim Reference Manual, v10.1c

Commands
examine

• -showbase
(optional) Display the number of bits of the vector and the radix used, where:
binary = b
decimal = d
hexidecimal = h
ASCII = a
time = t
For example, instead of simply displaying a vector value of “31”, a value of “16'h31” may
be displayed to show that the vector is 16 bits wide, with a hexidecimal radix.
• -time <time>
(optional) Specifies the time value between 0 and $now for which to examine the objects.
<time> — A non negative integer where the default unit is the current time unit. If the
<time> field uses a unit other than the current unit, the value and unit must be placed
in curly braces. For example, the following are equivalent for ps resolution:
exa -time {3.6 ns} signal_a
exa -time 3600 signal_a

If an expression is specified it will be evaluated at that time. The objects to be examined

must be logged via the add list, add wave, or log command in order for the examine
command to be able to return a value for a requested time.
• -value
(default) Returns value(s) as a curly-braces separated Tcl list. Use to toggle off a previous
use of -name.
Examples
• Return the value of /top/bus1.
examine /top/bus1

• Return the value of the subelement of rega that is specified by the index (i.e., 16). Note
that you must use curly braces when examining subelements.examine
{rega[16]}

• Return the value of the contiguous subelements of foo specified by the slice (i.e., 20:22).
Note the curly braces.
examine {foo[20:22]}

• Note that when specifying an object that contains an extended identifier as the last part
of the name, there must be a space after the closing '\' and before the closing '}'.
examine {/top/\My extended id\ }

• In this example, the -expr option specifies a signal path and user-defined Tcl variable.
The expression will be evaluated at 3450us.

ModelSim Reference Manual, v10.1c 133

Commands
examine

examine -time {3450 us} -expr {/top/bus and $bit_mask}

• Using the ${fifo} syntax limits the variable to the simple name fifo, instead of
interpreting the parenthesis as part of the variable. Quotes are needed when spaces are
involved; and by using quotes (“ “) instead of braces, the Tcl interpreter will expand
variables before calling the command.
examine -time $t -name $fifo "${fifo}(1 to 3)" ${fifo}(1)

• Because -time is not specified, this expression will be evaluated at the current
simulation time. Note the signal attribute and array constant specified in the expression.
examine -expr {clk’event && (/top/xyz == 16’hffae)}

Commands like find and examine return their results as a Tcl list (just a blank-separated
list of strings). You can do things like:
foreach sig [find sig ABC*] {echo "Signal $sig is [exa $sig]" …}

if {[examine -bin signal_12] == “11101111XXXZ”} {…}

examine -hex [find *]

Related Topics
• Design Object Names •
• Wildcard Characters
• DefaultRadix modelsim.ini variable

134 ModelSim Reference Manual, v10.1c

Commands
exit

exit
This command exits the simulator and the ModelSim application.
If you want to stop the simulation using a when command, use a stop command within your
when statement, do not use an exit command or a quit command. The stop command acts like a
breakpoint at the time it is evaluated.
Syntax
exit [-force] [-code <integer>]
Argument
• -force
(optional) Quits without asking for confirmation. If this argument is omitted, ModelSim
asks you for confirmation before exiting. You can also use -f as an alias for this switch.
• -code <integer>
(optional) Quits the simulation and issues an exit code.
<integer> — This is the value of the exit code. You should not specify an exit code that
already exists in the tool. Refer to the section "Exit Codes" in the User’s Manual for a
list of existing exit codes. You can also specify a variable in place of <integer>.
You should always print a message before executing the exit -code command to explicitly
state the reason for exiting.
Examples
You can use exit -code to instruct a vmake command to exit when it encounters an assertion
error. The onbreak command can specify commands to be executed upon an assert failure of
sufficient severity, after which the simulator can be made to return an exit status. This is shown
in the following example:

set broken 0
onbreak {
set broken 88
resume
}
run -all
if { $broken } {
puts "failure -- exit status $broken"
exit -code $broken
} else {
puts "success"
}
quit -f

The resume command gives control back to the commands following the run -all to handle the
condition appropriately.

ModelSim Reference Manual, v10.1c 135

Commands
find

find
This command locates objects by type and name. Arguments to the command are grouped by
object type:
• Arguments for nets and signals
• Arguments for instances and blocks
• Arguments for virtuals
• Arguments for classes
• Arguments for objects
Syntax
find nets | signals <object_name> … [-internal] [-nofilter] {[-in] [-inout] [-out] | [-ports]}
[-recursive]
find instances | blocks {<object_name> … | -bydu <design_unit> | -file <file_name>}
[-recursive] [-nodu]
find virtuals <object_name> … [-kind <kind>] [-unsaved] [-recursive]
find classes [<class_name>]
find objects [-class <class_name>] [-isa <class_name>] [<object_name>]
Arguments for nets and signals
When searching for nets and signals, the find command returns the full pathname of all nets,
signals, registers, variables, and named events that match the name specification.
• <object_name> …
(required) Specifies the net or signal for which you want to search. Multiple nets and signals
and wildcard characters are allowed. Wildcards cannot be used inside of a slice
specification. Spaces, square brackets, and extended identifiers require special syntax; see
the examples below for more details.
• -in
(optional) Specifies that the scope of the search is to include ports of mode IN.
• -inout
(optional) Specifies that the scope of the search is to include ports of mode INOUT.
• -internal
(optional) Specifies that the scope of the search is to include internal (non-port) objects.
• -nofilter
(optional) Specifies that the WildcardFilter Tcl preference variable be ignored when finding
signals or nets.

136 ModelSim Reference Manual, v10.1c

Commands
find

• -out
(optional) Specifies that the scope of the search is to include ports of mode OUT.
• -ports
(optional) Specifies that the scope of the search is to include all ports. Has the same effect as
specifying -in, -out, and -inout together.
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region.
Arguments for instances and blocks
When searching for instances, the find command returns the primary design unit name.
• -bydu <design_unit>
Searches for a design unit. Mutually exclusive with -file and <object_name>.
<design_unit> — Name of a single design unit to search for. This argument matches the
pattern specified by primary <design_unit> of the instance only. Library and
Secondary names are not supported.
• -file <file_name>
Writes a complete list of the instances in a design to a file. Mutually exclusive with -bydu
and <object_name>.
<file_name> — A string specifying the name for a file.
• <object_name> …
Specifies the name of an instance or block for which you want to search. Multiple instances
and wildcard characters are allowed. Mutually exclusive with -file and -bydu.
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region.
• -nodu
(optional) Removes the "du" string from the names of design units found with -bydu
argument.
Arguments for virtuals
When searching for virtuals, all optional arguments must be specified before any object names.
• <object_name> …
(required) Specifies the virtual object for which you want to search. Multiple virtuals and
wildcard characters are allowed.
• -kind <kind>
(optional) Specifies the kind of virtual object for which you want to search.

ModelSim Reference Manual, v10.1c 137

Commands
find

<kind> — A virtual object of one of the following kinds:

• designs
• explicits
• functions
• implicits
• signals.
• -unsaved
Specifies that ModelSim find only virtuals that have not been saved to a format file.
Arguments for classes
• <class_name>
(optional) Specifies the incrTcl class for which you want to search. Wildcard characters are
allowed. The options for class_name include nets, objects, signals, and virtuals. If you do
not specify a class name, the command returns all classes in the current namespace context.
See incrTcl commands in the Tcl Man Pages (Help > Tcl Man Pages) for more information.
Arguments for objects
• -class <class_name>
(optional) Restricts the search to objects whose most-specific class is class_name.
• -isa <class_name>
(optional) Restricts the search to those objects that have class_name anywhere in their
heritage.
• <object_name>
(optional) Specifies the incrTcl object for which you want to search. Wildcard characters are
allowed. If you do not specify an object name, the command returns all objects in the
current namespace context. See incrTcl commands in the Tcl Man Pages (Help > Tcl Man
Pages) for more information.
Description
The following rules are used by the find command to locate an object:
• If the name does not include a dataset name, then the current dataset is used.
• If the name does not start with a path separator, then the current context is used.
• If the name is a path separator followed by a name that is not the name of a top-level
design unit, then the first top-level design unit in the design is used.
• For a relative name containing a hierarchical path, if the first object name cannot be
found in the current context, then an upward search is done up to the top of the design
hierarchy to look for a matching object name.

138 ModelSim Reference Manual, v10.1c

Commands
find

• If no objects of the specified name can be found in the specified context, then an upward
search is done to look for a matching object in any visible enclosing scope up to an
instance boundary. If at least one match is found within a given context, no (more)
upward searching is done; therefore, some objects that may be visible from a given
context will not be found when wildcards are used if they are within a higher enclosing
scope.
• The wildcards '*' and '?' can be used at any level of a name except in the dataset name
and inside of a slice specification. Square bracket ([]) wildcards can also be used.
• A wildcard character will never match a path separator. For example, /dut/* will match
/dut/siga and /dut/clk. However, /dut* won’t match either of those.
• Because square brackets are wildcards in the find command, only parentheses (()) can be
used to index or slice arrays.
• The WildcardFilter Tcl preference variable is used by the find command to exclude the
specified types of objects when performing the search.
See Design Object Names for more information on specifying names.
Examples
• Find all signals in the entire design.
find signals -r /*

• Find all input signals in region /top that begin with the letters "xy".
find nets -in /top/xy*

• Find all signals in the design hierarchy at or below the region <current_context>/u1/u2
whose names begin with "cl".
find signals -r u1/u2/cl*

• Find a signal named s1. Note that you must enclose the object in curly braces because of
the square bracket wildcard characters.
find signals {s[1]}

• Find signals s1, s2, or s3.

find signals {s[123]}

• Find the element of signal s that is indexed by the value 1. Note that the find command
uses parentheses (()), not square brackets ([]), to specify a subelement index.
find signals s(1)

• Find a 4-bit array named data. Note that you must use curly braces ({}) due to the
spaces in the array slice specification.
find signals {/top/data(3 downto 0)}

ModelSim Reference Manual, v10.1c 139

Commands
find

• Note that when specifying an object that contains an extended identifier as the last part
of the name, there must be a space after the closing '\' and before the closing '}'.
find signals {/top/\My extended id\ }

• If /dut/core/pclk exists, prints the message "pclk does exist" in the transcript. This would
typically be run in a Tcl script.
if {[find signals /dut/core/pclk] != ""} {
echo "pclk does exist"

• Find instances based on their names using wildcards. Send search results to a text file
that lists instance names, including the hierarchy path, on separate lines.
# Search for all instances with u1 in path
set pattern_match "*u1*" ;

# Get the list of instance paths

set inst_list [find instances -r *] ;

# Initialize an empty list to strip off the architecture names

set ilist [list] ;

foreach inst $inst_list {

set ipath [lindex $inst 0]
if {[string match $pattern_match $ipath]} {
lappend ilist $ipath
}
}
# At this point, ilist contains the list of instances only--
# no architecture names
#
# Begin sorting list
set ilist [lsort -dictionary $ilist]

# Open a file to write out the list

set fhandle [open "instancelist.txt" w]
foreach inst $ilist {
# Print instance path, one per line
puts $fhandle $inst
}

# Close the file, done.

close $fhandle ;

Related Topics
• Design Object Names
• Wildcard Characters

140 ModelSim Reference Manual, v10.1c

Commands
find connections

find connections
This command returns the set of nets that are electrically equivalent to a specified net.
Syntax
find connections <net>
• <net> — (required) A net in the design. Returns a list of nets connected to the specified net.
For example:
find connections /top/p/strb

returns:
# Connected nets for strb
# output : /top/p/strb
# internal : /top/pstrb
# input : /top/c/pstrb

ModelSim Reference Manual, v10.1c 141

Commands
find infiles

find infiles
This command searches for a string in the specified file(s) and prints the results to the
Transcript window. The results are individually hotlinked and will open the file and display the
location of the string.
When you execute this command in command-line mode from outside of the GUI, the results
are sent to stdout with no hotlinks.
Arguments to this command are order dependent. Follow the order specified in the Syntax
section.
Syntax
find infiles <string_pattern> <file>...
Arguments
• <string_pattern>
(required) The string you are searching for. You can use Tcl regular expression wildcards to
further restrict the search capability.
• <file>...
(required) The file(s) to search. You can use Tcl regular expression wildcards to further
restrict the search capability.
Example
Figure 2-2 shows a screen capture containing a few examples of the find infiles command
and the results.

Figure 2-2. find infiles Example

142 ModelSim Reference Manual, v10.1c

Commands
find insource

find insource
This command searches for a string in the source files for the current design and prints the
results to the Transcript window. The results are hotlinked individually and will open the file
and display the location of the string.
When you execute this command in command-line mode from outside of the GUI, the results
are sent to stdout with no hotlinks.
Syntax
find insource <pattern> [-exact | -glob | -regex] [-inline] [-nocase]
Arguments
• <pattern>
(required) The string you are searching for. You can use regular expression wildcards to
further restrict the search. You must enclose <pattern> in quotes (“ “) if it includes spaces.
You must specify the <pattern> at the end of the command line; any switches specified after
<pattern> will not be registered.
• -exact | -glob | -regex
(optional) Defines the style of regular expression used in the <pattern>
-exact — Indicates that no characters have special meaning, thus disabling wildcard
features.
-glob — (default) Allows glob-style wildcard characters. For more information refer to
the Tcl documentation:
Help > Tcl Man Pages
Select “Tcl Commands”, then “string”, then “string match”
-regex — Allows Tcl regular expressions. For more information refer to the Tcl
documentation:
Help > Tcl Man Pages
Select “Tcl Commands”, then “re_syntax”.
• -inline
(optional) Returns the matches in the form of a Tcl list, which disables the hotlink feature
but allows for easier post-processing.
• -nocase
(optional) Treats <pattern> as case-insensitive.
Example
Figure 2-3 shows a couple of examples of the find insource command and the results.

ModelSim Reference Manual, v10.1c 143

Commands
find insource

Figure 2-3. find insource Example

Related Topics
DISABLE_ELAB_DEBUG environment
variable

144 ModelSim Reference Manual, v10.1c

Commands
force

force
This command allows you to apply stimulus interactively to VHDL signals, Verilog nets and
registers, and SystemC boundary types.
It is possible to create a complex sequence of stimuli when the force command is included in a
macro file.
There are a number of constraints on what you can and cannot force.
You can force:

• VHDL signals or parts of signals.

• Verilog nets and registers, bit-selects, part-selects, and field-selects. Refer to “Force and
Release Statements in Verilog” for more information.
• “Virtual Signals” if the number of bits corresponds to the signal value.
• An alias of a VHDL signal.
• An input port that is mapped at a higher level in VHDL and mixed models.
You cannot force:

• Virtual functions.
• VHDL variables. Refer to the change command for information on working with VHDL
variables.
• An input port that has a conversion function on the input or on the path up the network
mapped from the input.
This command provides additional information with the -help switch.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
Forcing values, driver type, repetition time or stop time on an object
force {<object_name> <value> [[@]<time_info>][, <value> [@]<time_info>]...
[-deposit | -drive | -drive] [-cancel [@]<time_info>] [-repeat [@]<time_info>]
Reporting all force commands

If you specify this command without arguments, it returns a list of the most recently applied force
commands and a list of forces coming from the Signal Spy signal_force() and $signal_force()
calls from within VHDL, Verilog, and SystemC source code. For example, after executing:
force -freeze /top/p/addr 0 100, 1 150 -r 200 -cancel 2000

the times specified are relative to the current simulation time, in this case 2820 ns
entering:

ModelSim Reference Manual, v10.1c 145

Commands
force

force

returns:
# force -freeze /top/p/addr 0 {@2920 ns} , 1 {@2970 ns}
-repeat {@3020 ns} -cancel {@4820 ns}

Note
The simulator translates the relative time you specify into absolute time when the force
command is executed.

Arguments
• <object_name>
(required when forcing a value change) Specifies the name of the HDL object to be forced.
A wildcard is permitted only if it matches one object. Refer to Design Object Names and Tcl
Syntax and Specification of Array Bits and Slices for the full syntax of an object name. The
object name must specify a scalar type or a one-dimensional array of character enumeration.
You may also specify a record sub-element, an indexed array, or a sliced array, as long as
the type is one of the above. Must be specified as the first argument to the force command.
• <value>
(required when forcing a value change) Specifies the value to which the object is to be
forced. The specified value must be appropriate for the type. Must be specified as the
second argument to the force command.
A one-dimensional array of character enumeration can be forced as a sequence of character
literals or as a based number with a radix of 2, 8, 10 or 16. For example, the following
values are equivalent for a signal of type bit_vector (0 to 3):
Description VHDL Value Verilog Value
character literal sequence 1111 1111
binary radix 2#1111 'b1111
octal radix 8#17 'o17
decimal radix 10#15 'd15
hexadecimal radix 16#F 'hF

Note
For based numbers in VHDL, ModelSim translates each 1 or 0 to the appropriate value
for the number’s enumerated type. The translation is controlled by the translation table in
the pref.tcl file. If ModelSim cannot find a translation for 0 or 1, it uses the left bound of
the signal type (type’left) for that value.

You can create a sequence of forced values on an object by specifying <value>

[@]<time_info> in a comma/space separated list.

146 ModelSim Reference Manual, v10.1c

Commands
force

For example:
force /top/p/addr 1 100ns, 0 200ns, 1 250ns

• -cancel [@]<time_info>
(optional) Cancels the force command at the time specified by <time_info>.
where:
<time_info> is [@]<time_value>[<time_unit>]
Refer to [@]<time_info> for more information about specifying time values.
• -drive
(optional) Attaches a driver to the object and drives the specified <value> until the object is
forced again or until it is unforced with the noforce command.
This option is illegal for unresolved signals.
• -deposit
(optional) Sets the object to the specified <value>. The <value> remains until the object is
forced again, there is a subsequent driver transaction, or it is unforced with a noforce
command.
Note
If the -freeze, -drive, or -deposit options are not used, then -freeze is the default for
unresolved objects, and -drive is the default for resolved objects. If you prefer -freeze as
the default for resolved and unresolved VHDL signals, change the DefaultForceKind
variable in the modelsim.ini file.

• -freeze
(optional) Freezes the object at the specified <value> until it is forced again or until it is
unforced with the noforce command.
Note
If you prefer -freeze as the default for resolved and unresolved VHDL signals, change the
DefaultForceKind variable in the modelsim.ini file.

• -repeat [@]<time_info>
(optional) Repeats a series of forced values and times at the time specified.
where:
<time_info> is [@]<time_value>[<time_unit>]
Refer to [@]<time_info> for more information about specifying time values.
You must specify at least two <value> <time_info> pairs on the forced object before
specifying -repeat, for example:
force top/dut/p 1 0, 0 100 -repeat 200 -cancel 1000

ModelSim Reference Manual, v10.1c 147

Commands
force

A repeating force command will force a value before other non-repeating force commands
that occur in the same time step.
• [@]<time_info>
(optional) Specifies the relative or absolute simulation time at which the <value> is to be
applied.
where:
<time_info> is [@]<time_value>[<time_unit>]
@ — A prefix applied to <time_value> to specify an absolute time. By default, the
specified time units are assumed to be relative to the current time unless the value is
preceded by the character "at" ( @ ). Omit the "at" (@) character to specify relative
time. For example:
-cancel {520 ns} \\ Relative Time
-cancel {@ 520 ns} \\ Absolute Time

<time_value> — The time (either relative or absolute) to apply to <value>. Any non-
negative integer. A value of zero cancels the force at the end of the current time
period.
<time_unit> — An optional suffix specifying a time unit where the default is to use the
current simulator time by omitting <time_unit>. Valid time units are: fs. ps, ns, us,
ms, sec, min, and hr.
<time_value> and <time_unit> can be formatted in any of the following ways:
10ns
10 ns
{10 ns}
“10 ns”

Note
If you specify a sequence of forces and use curly braces ({}) surrounding a <time_value>
and <time_unit> pair, you must place a space in front of the comma (,) separating the two
value/time pairs. For example:

force foo 1 {10 ns} , 0 {20 ns}

Examples
• Reporting all recently applied force commands
If you specify this command with no arguments, it returns a list of all forced objects and the
changes applied. For example, after executing:
force -freeze /top/p/addr 0 100, 1 150 -r 200 -cancel 2000

where the times specified are relative to the current simulation time, in this case 2820 ns.
Entering:
force

148 ModelSim Reference Manual, v10.1c

Commands
force

returns:
# force -freeze /top/p/addr 0 {@2920 ns} , 1 {@2970 ns}
-repeat {@3020 ns} -cancel {@4820 ns}

Note
Executing the force command translates the relative time you specified into absolute
time.

• Force input1 to 0 at the current simulator time.

force input1 0

• Force the fourth element of the array bus1 to 1 at the current simulator time.
force bus1(4) 1

• Force bus1 to 01XZ at 100 nanoseconds after the current simulator time.
force bus1 01XZ 100 ns

• Force bus1 to 16#F at the absolute time 200 measured in the resolution units selected at
simulation start-up.
force bus1 16#f @200

• Force input1 to 1 at 10 time units after the current simulation time and to 0 at 20 time
units after the current simulation time. Repeat this cycle every 100 time units after the
current simulation time, If the current simulation time is 100 ns, the next transition is to
1 at 110 ns and 0 at 120 ns, this pattern to start repeating at 200 ns.
force input1 1 10, 0 20 -r 100

• Similar to the previous example, but also specifies the time units.
force input1 1 10 ns, 0 20 ns -r 100 ns

• Force signal s to alternate between values 1 and 0 every 100 time units until 1000 time
units have occurred, starting from time Now. Cancellation occurs at the last simulation
delta cycle of a time unit.
force s 1 0, 0 100 -repeat 200 -cancel 1000

So,
force s 1 0 -cancel 0

will force signal s to 1 for the duration of the current time period.
• Force siga to decimal value 85 whenever the value on the signal is 1.
when {/mydut/siga = 10#1} {
force -deposit /mydut/siga 10#85
}

• Force one bit of a record containing an array.

ModelSim Reference Manual, v10.1c 149

Commands
force

force struct1.bus1(4) 1

• Force a slice of an array.

force {bus1[2:5]} 'hF

Related Topics
• change • Force Command Defaults
• DefaultForceKind • noforce
• Design Object Names • Virtual Signals
• Force and Release Statements in Verilog

150 ModelSim Reference Manual, v10.1c

Commands
formatTime

formatTime
This command provides global format control for all time values displayed in the GUI. When
specified without arguments, this command returns the current state of the three arguments.
Syntax
formatTime [[+|-]commas] [[+|-]nodefunits] [[+|-]bestunits]
Arguments
• [+|-]commas
(optional) Insert commas into the time value.
+ prefix — On
- prefix — Off. (default)
• [+|-]nodefunits
(optional) Do not include default unit in the time.
+ prefix — On
- prefix — Off. (default)
• [+|-]bestunits
(optional) Use the largest unit value possible.
+ prefix — On
- prefix — Off. (default)
Examples
• Display commas in time values.
formatTime +commas

Instead of displaying 6458131 ps, the GUI will display 6,458,131 ps.
• Use largest unit value possible.
formatTime +bestunits

Displays 8 us instead of 8,000 ns.

ModelSim Reference Manual, v10.1c 151

Commands
help

help
This command displays in the Transcript window a brief description and syntax for the
specified command.
Syntax
help [<command> | <topic>]
Arguments
• <command>
(optional) Specifies the command for which you want help. The entry is case and space
sensitive.
• <topic>
(optional) Specifies a topic for which you want help. The entry is case and space sensitive.
Specify one of the following six topics:
Topic Description
commands Lists all available commands and
topics
debugging Lists debugging commands
execution Lists commands that control
execution of your simulation.
Tcl Lists all available Tcl commands.
Tk Lists all available Tk commands
incrTCL Lists all available incrTCL
commands

152 ModelSim Reference Manual, v10.1c

Commands
history

history
This command lists the commands you have executed during the current session. History is a
Tcl command. For more information, consult the Tcl Man Pages (Help > Tcl Man Pages).
Syntax
history [clear] [keep <value>]
Arguments
• clear
(optional) Clears the history buffer.
• keep <value>
(optional) Specifies the number of executed commands to keep in the history buffer.
<value> — Any positive integer where the default is 50.

ModelSim Reference Manual, v10.1c 153

Commands
layout

layout
This command allows you to perform a number of editing operations on custom GUI layouts,
such as loading, saving, maximizing, and deleting.
The command options include:
• layout active – returns the current active window
• layout current – lists the current layout
• layout delete – removes the current layout from the .modelsim file (UNIX/Linux) or
Registry (Windows)
• layout load – opens the specified layout
• layout names – lists all known layouts
• layout normal – minimizes the current maximized window
• layout maximized – return a 1 if the current layout is maximized, or a 0 if minimized
• layout restoretype — removes the list of window type(s) that will not be restored when a
new layout is loaded.
• layout save – saves the current layout to the specified name
• layout showsuppresstypes — lists the window types that will not be restored when a
new layout is loaded.
• layout suppresstype — adds the specified window type(s) to the list of types that will not
be restored when a layout is reloaded.
• layout togglezoom – toggles the current zoom state of the active window (from
minimized to maximized or maximized to minimized)
• layout zoomactive – maximizes the current active window
• layout zoomwindow – maximizes the specified window
Syntax
layout active
layout current
layout delete <name>
layout load <name>
layout names
layout normal
layout maximized
layout restoretype <window>

154 ModelSim Reference Manual, v10.1c

Commands
layout

layout save <name>

layout showsuppresstypes
layout suppresstype <window>
layout togglezoom
layout zoomactive
layout zoomwindow <window>
Arguments
• <name>
(required) Specifies the name of the layout.
• <window>
(required) The window specification can be any format accepted by the view command. The
window can be specified by its type (i.e., wave, list, objects, etc.), by the windowobj name
(i.e., .main_pane.wave, .main_pain.library, etc.), or by the tab name (i.e., wave1, list3, etc.)
Related Topics
• Customizing the Simulator GUI Layout
• Configuring Default Windows for
Restored Layouts

ModelSim Reference Manual, v10.1c 155

Commands
log

log
This command creates a wave log format (WLF) file containing simulation data for all HDL
objects whose names match the provided specifications. Objects that are displayed using the
add list and add wave commands are automatically recorded in the WLF file. By default the file
is named vsim.wlf and stored in the current working directory. You can change the default name
using the -wlf option of the vsim command or by setting the WLFFilename variable in the
modelsim.ini file.
If no port mode is specified, the WLF file contains data for all objects in the selected region
whose names match the object name specification.
The WLF file contains a record of all data generated for the list and wave windows during a
simulation run. Reloading the WLF file restores all objects and waveforms and their complete
history from the start of the logged simulation run. See dataset open for more information.
For all transaction streams created through the SCV or Verilog APIs, logging is enabled by
default. A transaction is logged to the WLF file if logging is enabled at the beginning of a
simulation run when the design calls ::begin_transaction() or $begin_transaction. The effective
start time of the transaction (the time passed by the design as a parameter to ::begin_transaction)
is irrelevant. For example, a stream could have logging disabled between T1 and T2 and still
record a transaction in that period, through retroactive logging after time T2. A transaction is
always either entirely logged or entirely ignored.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Note
The log command is also known as the "add log" command.

Syntax
log [-howmany] {[-in] [-inout] [-out] | [-ports]} [-internal]
[-out] [-ports] [-recursive [-depth <level>]] <object_name> …
log -flush [<object>]
Arguments
• -depth <level>
(optional) Restricts a recursive search (specified with the -recursive argument) to a certain
level of hierarchy.
<level> — Any non-negative integer. For example, if you specify -depth 1, the
command descends only one level in the hierarchy.
• -flush [<object>]
(optional) Forced the WLF file to write all buffered region and event data to the WLF file.
By default, the region and event data is buffered and periodically written to the file, as
appropriate. If <object> is specified, that object is first logged and then the file is flushed.

156 ModelSim Reference Manual, v10.1c

Commands
log

• -howmany
(optional) Returns an integer indicating the number of signals found.
• -in
(optional) Specifies that the WLF file is to include data for ports of mode IN whose names
match the specification.
• -inout
(optional) Specifies that the WLF file is to include data for ports of mode INOUT whose
names match the specification.
• -internal
(optional) Specifies that the WLF file is to include data for internal (non-port) objects whose
names match the specification.
• -out
(optional) Specifies that the WLF file is to include data for ports of mode OUT whose
names match the specification.
• -ports
(optional) Specifies that the scope of the search is to include all ports, IN, INOUT, and
OUT.
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region. You can use the -depth argument to
specify how far down the hierarchy to descend.
• <object_name>
(required) Specifies the object name that you want to log. Must be specified as the final
argument to the log command. Multiple object names are specified as a space separated list.
Wildcard characters are allowed. Note that the WildcardFilter Tcl preference variable
identifies types to ignore when matching objects with wildcard patterns.
By default, wildcard card logging does not log the internals of cells. Refer to the +libcell |
+nolibcell argument of the vlog command for more information.
Examples
• Log all objects in the design.
log -r /*

• Log all output ports in the current design unit.

log -out *

ModelSim Reference Manual, v10.1c 157

Commands
log

Related Topics
• add list • dataset restart
• add wave • dataset rename
• dataset alias • dataset save
• dataset clear • dataset snapshot
• dataset close • nolog
• dataset config • Recording Simulation Results With
• dataset config Datasets
• dataset info • vlog +libcell | +nolibcell
• dataset list • Wildcard Characters
• dataset open

158 ModelSim Reference Manual, v10.1c

Commands
lshift

lshift
This command takes a Tcl list as an argument and shifts it in-place, one place to the left,
eliminating the left-most element.
The number of shift places may also be specified. Returns nothing.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
lshift <list> [<amount>]
Arguments
• <list>
(required) Specifies the Tcl list to target with lshift. Must be specified as the first argument
to the lshift command.
• <amount>
(optional) Specifies the number of places to shift where the default is 1.
Examples
proc myfunc args {
# throws away the first two arguments
lshift args 2
...
}

Related Topics
• Refer to the Tcl man pages (Help > Tcl
Man Pages) for details.

ModelSim Reference Manual, v10.1c 159

Commands
lsublist

lsublist
This command returns a sublist of the specified Tcl list that matches the specified Tcl glob
pattern.
Arguments to this command are order dependent. Follow the order specified in the Syntax
section.
Syntax
lsublist <list> <pattern>
Arguments
• <list>
(required) Specifies the Tcl list to target with lsublist.
• <pattern>
(required) Specifies the pattern to match within the <list> using Tcl glob-style matching.
Examples
• In the example below, variable ‘t’ returns "structure signals source".
set window_names "structure signals variables process source wave
list"
set t [lsublist $window_names s*]

Related Topics
• The set command is a Tcl command. Refer
to the Tcl man pages (Help > Tcl Man
Pages) for details.

160 ModelSim Reference Manual, v10.1c

Commands
mem compare

mem compare
This command compares a selected memory to a reference memory or file. Must have the "diff"
utility installed and visible in your search path in order to run this command.
Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
mem compare {[-mem <ref_mem>] | [-file <ref_file>]} [actual_mem]
Arguments
• -mem <ref_mem>
(optional) Specifies a reference memory to be compared with actual_mem.
<ref_mem> — A memory record.
• -file <ref_file>
(optional) Specifies a reference file to be compared with actual_mem.
<ref_file> — A saved memory file.
• actual_mem
(required) Specifies the name of the memory to be compared against the reference data.
Must be specified as the final argument to the mem compare command.

ModelSim Reference Manual, v10.1c 161

Commands
mem display

mem display
This command prints to the Transcript window the memory contents of the specified instance. If
the given instance path contains only a single array signal or variable, the signal or variable
name need not be specified.
You can redirect the output of the mem display command into a file for later use with the mem
load command. The output file can also be read by the Verilog $readmem system tasks if the
memory module is a Verilog module and Verilog memory format (hex or binary) is specified.
Address radix, data radix, and address range for the output can also be specified, as well as
special output formats.
By default, identical data lines are printed. To replace identical lines with a single line
containing the asterisk character, you can enable compression with the -compress argument.
Note
The format settings are stored at the top of this file as a pseudo comment so that
subsequent mem load commands can correctly interpret the data. Do not edit this data
when manipulating a saved file.

Arguments to this command are order dependent. Please read through the argument descriptions
for more information.
Syntax
mem display [-addressradix [d | h]] [-compress] [-dataradix <radix_type>]
[-endaddress <end>][-format [bin | hex | mti]] [-noaddress] [-startaddress <st>]
[-wordsperline <n>] [<path>]
Arguments
• -addressradix [d | h]
(optional) Specifies the address radix for the default (MTI) formatted files.
d — Decimal radix. (default if -format is specified as mti.)
h — Hex radix.
• -compress
(optional) Specifies that identical lines not be printed. Reduces the file size by replacing
exact matches with a single line containing an asterisk. These compressed files are
automatically expanded during a mem load operation.
• -dataradix <radix_type>
(optional) Specifies the data radix for the default (MTI) formatted files. If unspecified, the
global default radix is used.
<radix_type> A specified radix type. Valid entries (or any unique abbreviations) are:
binary, decimal, unsigned, octal, hex, symbolic, and default. If no radix is specified
for an enumerated type, the symbolic representation is used.

162 ModelSim Reference Manual, v10.1c

Commands
mem display

You can change the default radix type for the current simulation using the radix command
or make the default radix permanent by editing the DefaultRadix variable in the
modelsim.ini file.
• -endaddress <end>
(optional) Specifies the end address for a range of addresses to be displayed.
<end> — Any valid address in the memory. If unspecified, the default is the end of the
memory.
• -format [bin | hex | mti]
(optional) Specifies the output format of the contents.
bin— Specifies a binary output.
hex— Specifies a hex output.
mti — MTI format. (default).
• -noaddress
(optional) Specifies that addresses not be printed.
• -startaddress <st>
(optional) Specifies the start address for a range of addresses to be displayed.
<st> — Any valid address in the memory. If unspecified, the default is the start of the
memory.
• -wordsperline <n>
(optional) Specifies how many words are to be printed on each line.
<n> — Any positive integer where the default is an 80 column display width.
• <path>
(required) Specifies the full path to the memory instance. The default is the current context,
as shown in the Structure window. Indexes can be specified. Must be specified as the final
argument to the mem display command.
Examples
• This command displays the memory contents of instance /top/c/mru_mem, addresses 5
to 10:
mem display -startaddress 5 -endaddress 10 /top/c/mru_mem

returns:
# 5: 110 110 110 110 110 000

• Display the memory contents of the same instance to the screen in hex format, as
follows:
mem display -format hex -startaddress 5 -endaddress 10 /top/c/mru_mem

returns:

ModelSim Reference Manual, v10.1c 163

Commands
mem display

# 5: 6 6 6 6 6 0

Related Topics
• For details on MTI format, refer to the
mem load description.

164 ModelSim Reference Manual, v10.1c

Commands
mem list

mem list
This command displays a flattened list of all memory instances in the current or specified
context after a design has been elaborated.
Each instance line is prefixed by "VHDL:" or "Verilog:", depending on the type of model.
Returns the signal/variable name, address range, depth, and width of the memory.
Syntax
mem list [-r] [<path>]
Arguments
• -r
(optional) Recursively descends into sub-modules when listing memories.
• <path>
(optional) The hierarchical path to the location the search should start where the default is
the current context, as shown in the Structure window.
Examples
• Recursively list all memories at the top level of the design.
mem list -r /

Returns:
# Verilog: /top/m/mem[0:255](256d x 16w)
#

• Recursively list all memories in /top2/uut.

mem list /top2/uut -r

Returns:
# Verilog: /top2/uut/mem[0:255] x 16w

ModelSim Reference Manual, v10.1c 165

Commands
mem load

mem load
This command updates the simulation memory contents of a specified instance. You can upload
contents either from a memory data file, a memory pattern, or both. If both are specified, the
pattern is applied only to memory locations not contained in the file.
A relocatable memory file is one that has been saved without address information. You can load
a relocatable memory file into the instance of a memory core by specifying an address range on
the mem load command line. If no address range (starting and ending address) is specified, the
memory is loaded starting at the first location.
The order in which the data is placed into the memory depends on the format specified by the
-format option. If you choose bin or hex format, the memory is filled low to high, to be
compatible with $readmem commands. This is in contrast to the default MTI format, which
fills the memory according to the memory declaration, from left index to right index.
For Verilog objects and VHDL integers and std_logic types: if the word width in a file is wider
than the word width of the memory, the leftmost bits (msb) in the data words are ignored. To
allow wide words use the -truncate option which will ignore the msb bits that exceed the
memory word size. If the word width in the file is less than the width of the memory, and the
leftmost digit of the file data is not ’X’, then the leftmost bits are zero filled. Otherwise, they are
X-filled.
The type of data required for the -filldata argument is dependent on the -filltype specified: a
fixed value, or one that governs an incrementing, decrementing, or random sequence.
• For fixed pattern values, the fill pattern is repeatedly tiled to initialize the memory block
specified. The pattern can contain multiple word values for this option.
• For incrementing or decrementing patterns, each memory word is treated as an unsigned
quantity, and each successive memory location is filled in with a value one higher or
lower than the previous value. The initial value must be specified.
• For a random pattern, a random data sequence will be generated to fill in the memory
values. The data type in the sequence will match the type stored in the memory. For
std_logic and associated types, unsigned integer sequences are generated. A seed value
may be specified on the command line. For any given seed, the generated sequence is
identical.
The interpretation of the pattern data is performed according to the default system radix setting.
However, this can be overridden with a standard Verilog-style ‘<radix_char><data>
specification.
Syntax
mem load {-infile <infile> | -filldata <data_word> [-infile <infile>]}
[-endaddress <end>] [-fillradix <radix_type>] [-filltype {dec | inc | rand | value}]
[-format [bin | hex | mti]] [<path>] [-skip <Nwords>] [-startaddress <st>] [-truncate]

166 ModelSim Reference Manual, v10.1c

Commands
mem load

Arguments
• -infile <infile>
(required unless the -filldata argument is used) Updates memory data from the specified
file.
<infile> — The name of a memory file.
• -endaddress <end>
(optional) Specifies the end address for a range of addresses to be loaded.
<end> — Specified as any valid address in the memory.
• -filltype {dec | inc | rand | value}
(optional, use with the -filldata argument) Fills in memory addresses in an algorithmic
pattern starting with the data word specified in -filldata. If a fill pattern is used without a file
option, the entire memory or specified address range is filled with the specified pattern. If
both are specified, the pattern is applied only to memory locations not contained in the file.
dec — Decrement each succeeding memory word by one digit.
inc — Increment each succeeding memory word by one digit.
rand — Randomly generate each succeeding memory word starting with the word
specified by -filldata as the seed.
value — Value (default) Substitute each memory word in the range with the value
specified in -filldata.
• -filldata <data_word>
(required unless -infile is used) Specifies a data word used to fill memory addresses in the
pattern specified by -filltype.
<data_word> — Specifies a data word. Must be in the same format as specified by the
-fillradix switch.
• -fillradix <radix_type>
(optional, use with -filldata) Specifies radix of the data specified by the -filldata switch.
<radix_type> — Valid entries (or any unique abbreviations) are: binary, decimal,
unsigned, octal, hex, symbolic, and default.
• -format [bin | hex | mti]
(optional, use with -infile) Specifies the format of the file to be loaded.
bin — Specifies binary data format.
hex — Specifies hex format.
mti — MTI format. (default).
Specifies the format of the file to be loaded. The bin and hex values are the standard Verilog
hex and binary memory pattern file formats. These can be used with Verilog memories, and
with VHDL memories composed of std_logic types.

ModelSim Reference Manual, v10.1c 167

Commands
mem load

In the MTI memory data file format, internal file address and data radix settings are stored
within the file itself. Thus, there is no need to specify these settings on the mem load
command line. If a format specified on the command line and the format signature stored
internally within the file do not agree, the file cannot be loaded.
• <path>
(optional) The hierarchical path to the memory instance. If the memory instance name is
unique, shorthand instance names can be used. The default is the current context, as shown
in the Structure window.
Memory address indexes can be specified in the instance name also. If addresses are
specified both in the instance name and the file, only the intersection of the two address
ranges is populated with memory data.
• -skip <Nwords>
(optional) Specifies the number of words to be skipped between each fill pattern value. Used
with -filltype and -filldata.
<Nwords> — Specified as an unsigned integer.
• -startaddress <st>
(optional) Specifies the start address for a range of addresses to be loaded.
<st> — Any valid address in the memory.
• -truncate
(optional) Ignores any most significant bits (msb) in a memory word which exceed the
memory word size. By default, when memory word size is exceeded, an error results.
Examples
• Load the memory pattern from the file vals.mem to the memory instance /top/m/mem,
filling the rest of the memory with the fixed-value 1‘b0.
mem load -infile vals.mem -format bin -filltype value -filldata 1'b0
/top/m/mem

When you enter the mem display command on memory addresses 0 through 12, you see
the following:
mem display -startaddress 0 -endaddress 12 /top/m/mem
# 0: 0000000000000000 0000000000000001 0000000000000010 0000000000000011
# 4: 0000000000000100 0000000000000101 0000000000000110 0000000000000111
# 8: 0000000000001000 0000000000001001 0000000000000000 0000000000000000
# 12: 0000000000000000

• Load the memory pattern from the file vals.mem to the memory instance
/top/m/mru_mem, filling the rest of the memory with the fixed-value 16'Hbeef.
mem load -infile vals.mem -format hex -st 0 -end 12 -filltype value -filldata 16'Hbeef
/top/m/mru_mem

168 ModelSim Reference Manual, v10.1c

Commands
mem load

• Load memory instance /top/mem2 with two words of memory data using the Verilog
Hex format, skipping 3 words after each fill pattern sequence.
mem load -filltype value -filldata "16'hab 16'hcd" /top/mem2 -skip 3

• Load memory instance /top/mem with zeros (0).

mem load -filldata 0 /top/mem

• Truncate the msb bits that exceed the maximum word size (specified in HDL code).
mem load -format h -truncate -infile data_files/data.out /top/m_reg_inc/mem

Related Topics
• mem save

ModelSim Reference Manual, v10.1c 169

Commands
mem save

mem save
This command saves the contents of a memory instance to a file in any of the supported
formats: Verilog binary, Verilog hex, and MTI memory pattern data.
This command works identically to the mem display command, except that its output is written
to a file rather than a display.
The order in which the data is placed into the saved file depends on the format specified by the
-format argument. If you choose bin or hex format, the file is populated from low to high, to be
compatible with $readmem commands. This is in contrast to the default mti format, which
populates the file according to the memory declaration, from left index to right index.
You can use the mem save command to generate relocatable memory data files. The
-noaddress option omits the address information from the memory data file. You can later load
the generated memory data file using the memory load command.
Syntax
mem save -outfile <filename> [-addressradix {dec | hex}] [-dataradix <radix_type>]
[-format {bin | hex | mti}] [-compress | -noaddress] [<path>]
[-startaddress <st> -endaddress <end>] [-wordsperline <Nwords>]
Arguments
• -outfile <filename>
(required) Specifies that the memory contents are to be stored in a file.
<filename> — The name of the file where the specified memory contents are to be
stored.
• -addressradix {dec | hex}
(optional) Specifies the address radix for the default mti formatted files.
dec — Decimal (default).
hex — Hexadecimal.
• -compress
(optional) Specifies that only unique lines are printed, identical lines are not printed.
Mutually exclusive with the -noaddress switch.
• -dataradix <radix_type>
(optional) Specifies the data radix for the default mti formatted files.
<radix_type> — Valid entries (or any unique abbreviations) are: binary, decimal,
unsigned, octal, hex, and symbolic.
You can change the default radix for the current simulation using the radix command. You
can change the default radix permanently by editing the DefaultRadix variable in the
modelsim.ini file.

170 ModelSim Reference Manual, v10.1c

Commands
mem save

• -endaddress <end>
(optional) Specifies the end address for a range of addresses to be saved.
<end> — Any valid address in the memory.
• -format {bin | hex | mti}
(optional) Specifies the format of the output file.
bin— Binary data format.
hex— Hexadecimal format.
mti — MTI format. (default).
The bin and hex values are the standard Verilog hex and binary memory pattern file formats.
These can be used with Verilog memories, and with VHDL memories composed of
std_logic types.
In the MTI memory data file format, internal file address and data radix settings are stored
within the file itself.
• -noaddress
(optional) Prevents addresses from being printed. Mutually exclusive with the -compress
switch.
• <path>
(optional) The hierarchical path to the location of the memory instance. The default is the
current context, as shown in the Structure window.
• -startaddress <st>
(optional) Specifies the start address for a range of addresses to be saved.
<st> — Any valid address in the memory.
• -wordsperline <Nwords>
(optional) Specifies how many memory values are to be printed on each line.
<Nwords> — Any unsigned integer where the default assumes an 80 character display
width.
Examples
• Save the memory contents of the instance /top/m/mem(0:10) to memfile, written in the
mti radix.
mem save -format mti -outfile memfile -start 0 -end 10 /top/m/mem

The contents of memfile are as follows:

// memory data file (do not edit the following line - required for mem
load use)
// format=mti addressradix=d dataradix=s version = 1.0
0: 0000000000000000 0000000000000001 0000000000000010 0000000000000011
4: 0000000000000100 0000000000000101 0000000000000110 0000000000000111
8: 0000000000001000 0000000000001001 xxxxxxxxxxxxxxxx

ModelSim Reference Manual, v10.1c 171

Commands
mem save

Related Topics
• mem display
• mem load

172 ModelSim Reference Manual, v10.1c

Commands
mem search

mem search
This command finds and prints to the screen the first occurring match of a specified memory
pattern in the specified memory instance. Shorthand instance names are accepted.
Optionally, you can instruct the command to print all occurrences. The search pattern can be
one word or a sequence of words.
Syntax
mem search {-glob <word> [<word>…] | -regexp <word> [<word>…]}
[-addressradix {dec | hex}] [-dataradix <radix_type>] [-all] [-replace <word> [<word>…]]
[-startaddress <address>] [-endaddress <address>] [<path>]
Arguments
• -glob <word> [<word>…]
(required unless using -regexp) Specifies the value of the pattern, accepting glob pattern
syntax for the search.
<word> — Any word pattern. Multiple word patterns are specified as a space separated
list. Wildcards are accepted in the pattern.
This argument and -regexp are mutually exclusive arguments.
• -regexp <word> [<word>…]
(required unless using -glob) Specifies the value of the pattern, accepting regular expression
syntax for the search.
<word> — Any word pattern. Wildcards are accepted in the pattern. Multiple word
patterns are specified as a space separated list.
This argument and -glob are mutually exclusive arguments.
• -addressradix {dec | hex}
(optional) Specifies the radix for the address being displayed.
dec — Decimal (default).
hex — Hexadecimal.
• -all
(optional) Searches the specified memory range and returns all matching occurrences to the
transcript. By default only the first matching occurrence is printed.
• -dataradix <radix_type>
(optional) Specifies the radix for the memory data being displayed.
<radix_type> — Can be specified as symbolic, binary, octal, decimal, unsigned, or hex. By
default the radix displayed is the system default.

ModelSim Reference Manual, v10.1c 173

Commands
mem search

You can change the default radix for the current simulation using the radix command. You
can change the default radix permanently by editing the DefaultRadix variable in the
modelsim.ini file.
• -endaddress <address>
(optional) Specifies the end address for a range of addresses to search.
<address> — Any valid address in the memory.
• <path>
(optional) Specifies the hierarchical path to the location of the memory instance. The default
is the current context, as shown in the Structure window.
• -replace <word> [<word>…]
(optional) Replaces the found patterns with a designated pattern.
<word> — A word pattern Multiple word patterns are accepted, separated by a single
space. No wildcards are allowed in the replaced pattern.
• -startaddress <address>
(optional) Specifies the start address for a range of addresses to search.
<address> — Any valid address in the memory.
Examples
• Search for and print to the screen all occurrences of the pattern 16‘Hbeef in
/uut/u0/mem3:
mem search -glob 16‘Hbeef -dataradix hex /uut/u0/mem3

Returns:
#7845: beef
#7846: beef
#100223: beef

• Search for and print only the first occurrence of 16‘Hbeef in the address range
7845:150000, replacing it with 16‘Hcafe in /uut/u1/mem3:
mem search -glob 16‘Hbeef -d hex -replace 16‘Hcafe -st 7846 -end 150000
/uut/u1/mem3

Returns:
#7846: cafe

• Replace all occurrences of 16‘Hbeef with 16‘Habe in /uut/u1/mem3:

mem search -glob 16‘Hbeef -r 16‘Habe -addressadix hex -all /uut/u1/mem3

Returns:

174 ModelSim Reference Manual, v10.1c

Commands
mem search

#1ea5: 2750
#1ea6: 2750
#1877f: 2750

• Search for and print the first occurrence any pattern ending in f:
mem search -glob "*f"

• Search for and print the first occurrence of this multiple word pattern:
mem search -glob "abe cafe" /uut/u1/mem3

• Search for patterns "0000 0000" or "0001 0000" in m/mem:

mem search -data hex -regexp {000[0|1] 0{4}} m/mem -all

• Search for a pattern that has any number of 0s followed by any number of 1s as a
memory location, and which has a memory location containing digits as the value:
mem search -regexp {^0+1+$ \d+} m/mem -all

• Search for any initialized location in a VHDL memory:

mem search -regexp {[^U]} -all <vhdl_memory>

ModelSim Reference Manual, v10.1c 175

Commands
messages clearfilter

messages clearfilter
This command removes any filter you have set in the Message Viewer. Refer to the section
“Message Viewer Filter Dialog Box” for additional information about filtering in the Message
Viewer.
Syntax
messages clearfilter
Arguments
• No arguments

176 ModelSim Reference Manual, v10.1c

Commands
messages setfilter

messages setfilter
This command performs the same action as the Message Viewer Filter Dialog Box, which
controls which messages are shown in the Message Viewer.
The ideal workflow for using this command is through the GUI:
1. View > Message Viewer.
2. Right-click in the Message Viewer and select Filter.
The Message Viewer Filter dialog box is displayed
3. Create your filter.
4. OK or Apply.
The Message Viewer updates based on your filter and a messages setfilter command,
which is equivalent to your settings, is output to the transcript.
5. Retain the messages setfilter command from the transcript for future use.
Syntax
messages setfilter <tcl_list>
Arguments
• <tcl_list> — The tcl_list argument is a complex string of tcl code that controls the filter
settings.
Examples
• Severity is error and time is greater than or equal to 100 ns
messages setfilter {{} \
( Severity Contains {Case Insensitive} error )} \
{AND ( Time >= 100 ns )}

• The objects field contains neither clock or reset

messages setfilter {{} \
( Object Contains {Case Sensitive} clock )} \
{NOR ( Object Contains {Case Sensitive} data )}

• The message string either contains reg_str2 or reg_str1

messages setfilter {{} \
( Message Contains {Case Insensitive} reg_str2 )} \
{OR ( Message Contains {Case Insensitive} reg_str1 )}

ModelSim Reference Manual, v10.1c 177

Commands
messages write

messages write
This command prints the contents of the Message Viewer window to a specified text file.
Syntax
messages write <filename>
Arguments
• <filename> — (required) Specifies the name of the file where the contents of the Message
Viewer window are to be saved.
Related Topics
• displaymsgmode modeslim.ini variable • “Message Viewer Window”
• msgmode modeslim.ini variable

178 ModelSim Reference Manual, v10.1c

Commands
modelsim

modelsim
The modelsim command starts the ModelSim GUI without prompting you to load a design.
This command is valid only for Windows platforms and may be invoked in one of three ways:
• from the DOS prompt
• from a ModelSim shortcut
• from the Windows Start > Run menu
To use modelsim arguments with a shortcut, add them to the target line of the properties of that
shortcut. (As expected, arguments also work on the DOS command line.)
You can invoke the simulator from either the ModelSim> prompt after the GUI starts or from a
DO file called by modelsim.
Syntax
modelsim [-do <macrofile>] [<license_option>] [-nosplash]
Arguments
• -do <macrofile>
(optional) Executes a DO file when modelsim is invoked.
<macrofile> — The name of a DO file
Note
In addition to the macro called by this argument, if a DO file is specified by the
STARTUP variable in modelsim.ini, it will be called when the vsim command is invoked.

• <license_option>
(optional) Restricts the search of the license manager.
• -nosplash
(optional) Disables the splash screen.
Related Topics
• do • Using a Startup File
• vsim

ModelSim Reference Manual, v10.1c 179

Commands
noforce

noforce
This command removes the effect of any active force commands on the selected HDL objects.
and also causes the object’s value to be re-evaluated.
Syntax
noforce <object_name> …
Arguments
• <object_name>
(required) Specifies the name of an object. Must match an object name used in a previous
force command. Multiple object names may be specified as a space separated list. Wildcard
characters are allowed.
Related Topics
• force
• Wildcard Characters

180 ModelSim Reference Manual, v10.1c

Commands
nolog

nolog
This command suspends writing of data to the wave log format (WLF) file for the specified
signals.
A flag is written into the WLF file for each signal turned off, and the GUI displays "-No Data-"
for the signal(s) until logging (for the signal(s)) is turned back on. Logging can be turned back
on by issuing another log command or by doing a nolog -reset.
Because use of the nolog command adds new information to the WLF file, WLF files created
when using the nolog command cannot be read by older versions of the simulator.
Transactions written in SCV or Verilog are logged automatically, and can be removed with the
nolog command. A transaction is logged into the .wlf file if logging is enabled (in other words,
if no nolog command has disabled it) for that stream at the time when the transaction was
begun. An entire span of a transaction is either logged or not logged, regardless of the begin and
end times specified for that transaction.
Syntax
nolog [-all] [-depth <level>] [-howmany] [-in] [-inout] [-internal] [-out] [-ports] [-recursive]
[-reset] [<object_name>…]
Arguments
• -all
(optional) Turns off logging for all signals currently logged.
• -depth <level>
(optional) Restricts a recursive search (specified with the -recursive argument) to a certain
level of hierarchy.
<level> — An integer greater than or equal to zero. For example, if you specify -depth 1,
the command descends only one level in the hierarchy.
• -howmany
(optional) Returns an integer indicating the number of signals found.
• -in
(optional) Turns off logging only for ports of mode IN whose names match the
specification.
• -inout
(optional) Turns off logging only for ports of mode INOUT whose names match the
specification.
• -internal
(optional) Turns off logging only for internal (non-port) objects whose names match the
specification.

ModelSim Reference Manual, v10.1c 181

Commands
nolog

• -out
(optional) Turns off logging only for ports of mode OUT whose names match the
specification.
• -ports
(optional) Specifies that the scope of the search is to include all ports.
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region. You can use the -depth argument to
specify how many levels of the hierarchy to descend.
• -reset
(optional) Turns logging back on for all unlogged signals.
• <object_name>…
(optional) Specifies the object name which you want to unlog. Multiple object names may
be specified as a space separated list. Wildcard characters are allowed.
Examples
• Unlog all objects in the design.
nolog -r /*

• Turn logging back on for all unlogged signals.

nolog -reset

Related Topics
• add list • log
• add wave

182 ModelSim Reference Manual, v10.1c

Commands
notepad

notepad
This command opens a simple text editor. It may be used to view and edit ASCII files or create
new files.
This mode can be changed from the Notepad Edit menu.
Returns nothing.
Syntax
notepad [<filename>] [-r | -edit]
Arguments
• <filename>
(optional) Name of the file to be displayed.
• -r
(optional) Specifies read-only mode.
• -edit
(optional) Specifies editing mode. Will not save changes to an existing file that has the
Read-only attribute turned on. (default)

ModelSim Reference Manual, v10.1c 183

Commands
noview

noview
This command closes a window in the ModelSim GUI. To open a window, use the view
command.
Syntax
noview <window_name>…
Arguments
• <window_name>…
(required) Specifies the window(s) to close. Multiple window types may be specified in a
space separated list. Wildcards permitted. At least one type (or wildcard) is required.
Refer to the view command for a complete list of possible arguments.
You can also close Source windows using the tab or file name.
Examples
• Close the Wave window named "wave1".
noview wave1

• Close all List windows.

noview List

Related Topics
• view

184 ModelSim Reference Manual, v10.1c

Commands
nowhen

nowhen
This command deactivates selected when commands.
Syntax
nowhen [<label>]
Arguments
• <label>
(optional) Specifies an individual when command. Wildcards may be used to select more
than one when command.
Examples
• Deactivate the when command labeled 99.
nowhen 99

• Deactivate all when commands.

nowhen *

Related Topics
• when

ModelSim Reference Manual, v10.1c 185

Commands
onbreak

onbreak
This command is used within a macro and specifies one or more scripts to be executed when
running a macro that encounters a breakpoint in the source code.
The onbreak setting will effect any run commands that follow the onbreak statement until
another onbreak command is issued. If a .do file is executed from within the macro, the .do file
script will inherit the onbreak setting specified prior to execution unless and until another
onbreak command is given, in which case, that onbreak setting will be in effect until the .do file
script completes at which point execution will return to the calling macro and the calling
macro's onbreak setting is restored. The script must be followed by a run command to take
effect.
Use an empty string to change the onbreak command back to its default behavior:
onbreak ""

In this case, the macro will be interrupted after a breakpoint occurs (after any associated bp
command string is executed).

If you specify this command in a macro without a script, the default behavior is to pause and
return control to the command line. You can then enter onbreak without arguments on the
command line after the macro has paused to return the current onbreak command string.

Syntax
onbreak <script>; <script>...
Arguments
• <script>
(optional) Any command or script can be used as an argument to onbreak. If you want to
use more than one command or script, use a semicolon to separate them or place them on
multiple lines and enclose the entire script in curly braces ({}) or quotation marks (“ “). You
must use the onbreak command before a run, run -continue, or step command. If a run or
step comand is issued within an onbreak script, the script will return immediately and any
following commands will not be executed. It is an error to execute any commands within an
onbreak command string following any of the run commands. This restriction applies to
any macros or Tcl procedures used in the onbreak command string.
Examples
• Examine the value of the HDL object data when a breakpoint is encountered. Then
continue the run command.
onbreak {exa data ; cont}

• Resume execution of the macro file on encountering a breakpoint.

onbreak resume

186 ModelSim Reference Manual, v10.1c

Commands
onbreak

• This set of commands test for assertions. Assertions are treated as breakpoints if the
severity level is greater than or equal to the current BreakOnAssertion variable setting
(refer to modelsim.ini Variables). By default a severity level of failure or above causes a
breakpoint; a severity level of error or below does not.
set broken 0
onbreak {
lassign [runStatus -full] status fullstat
if {$status eq "error"} {
# Unexpected error, report info and force an error exit
echo "Error: $fullstat"
set broken 1
resume
} elseif {$status eq "break"} {
# If this is a user break, then
# issue a prompt to give interactive
# control to the user
if {[string match "user_*" $fullstat]} {
pause
} else {
# Assertion or other break condition
set broken 2
resume
}
} else {
resume
}
}
run -all
if {$broken == 1} {
# Unexpected condition. Exit with bad status.
echo "failure"
quit -force -code 3
} elseif {$broken == 2} {
# Assertion or other break condition
echo "error"
quit -force -code 1
} else {
echo "success!"
}
quit -force

Related Topics
• abort • Useful Commands for Handling
• bp Breakpoints and Errors
• do • Macros (DO Files)
• onerror
• resume
• status

ModelSim Reference Manual, v10.1c 187

Commands
onElabError

onElabError
This command specifies one or more commands to be executed when an error is encountered
during the elaboration portion of a vsim command. The command is used by placing it within a
macro.
Use the onElabError command without arguments to return to a prompt.
Syntax
onElabError {[<command> [; <command>] …]}
Arguments
• <command>
(optional) Any command can be used as an argument to onElabError. If you want to use
more than one command, use a semicolon to separate the commands, or place them on
multiple lines. The entire command string must be placed in curly braces ({}).
Related Topics
• do

188 ModelSim Reference Manual, v10.1c

Commands
onerror

onerror
This command is used within a macro before a run command; it specifies one or more
commands to be executed when a running macro encounters an error.
Using the onerror command without arguments will return the current onerror command
string. Use an empty string (onerror ““) to change the onerror command back to its default
behavior. Use onerror with a resume command to allow an error message to be printed without
halting the execution of the macro file.
You can also set the global OnErrorDefaultAction Tcl variable to dictate what action ModelSim
takes when an error occurs. To set the variable on a permanent basis, you must define the
variable in a modelsim.tcl file (Refer to “The modelsim.tcl File” for details).
When your onerror command is successful, the macro will continue normally, unless your
command instructs the tool to quit, for example:
onerror {quit -f}

or
onerror {break}

However, if your onerror command is not successful, the simulator will be halted, for example:
onerrror {add wave b}

when you don’t have a signal named b.

The onerror command is executed when a Tcl command (for example, break.) encounters an
error in the macro file that contains the onerror command (note that a run command does not
necessarily need to be in process). Conversely, OnErrorDefaultAction will run even if the
macro does not contain a local onerror command. This can be useful when you run a series of
macros from one script, and you want the same behavior across all macros.
Syntax
onerror {[<command> [; <command>] …]}
Arguments
• <command>
(optional) Any command can be used as an argument to onerror. If you want to use more
than one command, use a semicolon to separate the commands, or place them on multiple
lines. The entire command string must be placed in curly braces ({}).
Example
• Force the simulator to quit if an error is encountered while the macro is running.
onerror {quit -f}

ModelSim Reference Manual, v10.1c 189

Commands
onerror

Related Topics
• abort • Useful Commands for Handling
• do Breakpoints and Errors
• onbreak • Macros (DO Files)
• resume
• status

190 ModelSim Reference Manual, v10.1c

Commands
onfinish

onfinish
This command controls simulator behavior when encountering $finish or sc_stop() in the design
code. When you specify this command without an argument, it returns the current setting.
Syntax
onfinish [ask | exit | final | stop | default]
Arguments
ask — (optional) In batch mode, the simulation will exit; in GUI mode, the user is
prompted for action.
exit — (optional) The simulation exits without asking for any confirmation.
final — (optional) The simulation executes all finish blocks before exiting.
stop — (optional) The simulation ends but remains loaded in memory, allowing for
easier post-simulation tasks.
default — (optional) Uses the current setting for the OnFinish variable in the
modelsim.ini file.
Related Topics
• OnFinish modelsim.ini variable • vsim -onfinish

ModelSim Reference Manual, v10.1c 191

Commands
pause

pause
This command interrupts the execution of a macro and allows you to perform interactive
Commands

debugging of a macro file. The command is placed within the macro to be debugged.
Syntax
pause
Arguments
• None.
Description
When a macro is interrupted during execution, the macro returns the prompt:
VSIM(paused)>

This “pause” prompt notifies you that a macro has been interrupted.
When a macro is paused, you can invoke another macro. If the second macro is interrupted, you
can continue invoking macros up to a nesting level of 50 macros.
The status command lists summary information about all interrupted macros.
Use the resume command to resume execution of the macro. Use the abort command to stop
execution of some or all of the macros.
Related Topics
• abort
• do
• resume
• run
• status

192 ModelSim Reference Manual, v10.1c

Commands
precision

precision
This command determines how real numbers display in the graphic interface (e.g., Objects,
Wave, Locals, and List windows). It does not affect the internal representation of a real number
and therefore precision values over 17 are not allowed.
Executing the precision command without any arguments returns the current precision setting.
Syntax
precision [<digits>[#]]
Arguments
• <digits>[#]
(optional) Specifies the number of digits to display where the default is 6.
# — A suffix that forces the display of trailing zeros. See examples for more details.
Examples
• Results in 4 digits of precision.
precision 4

For example:
1.234 or 6543

• Results in 8 digits of precision including trailing zeros.

precision 8#

For example:
1.2345600 or 6543.2100

• Results in 8 digits of precision but doesn’t print trailing zeros.

precision 8

For example:
1.23456 or 6543.21

ModelSim Reference Manual, v10.1c 193

Commands
printenv

printenv
This command prints to the Transcript window the current names and values of all environment
variables.
If variable names are given as arguments, returns only the names and values of the specified
variables.
Syntax
printenv [<var>…]
Arguments
• <var>…
(optional) Specifies the name(s) of the environment variable(s) to print.
Examples
• Print all environment variable names and their current values.
printenv

Returns:
# CC = gcc
# DISPLAY = srl:0.0
…

• Print the specified environment variables:

printenv USER HOME

Returns:
# USER = vince
# HOME = /scratch/srl/vince

194 ModelSim Reference Manual, v10.1c

Commands
process report

process report
This command creates a textual report of all processes displayed in the Process Window.
Syntax
process report [-file <filename>] [-append]
Arguments
• -file <filename>
(optional) Creates an external file where raw process data will be saved. If -file is not
specified, then the output is redirected to stdout.
<filename> — A user-specified name for the file.
• -append
(optional) Specifies that process data is to be appended to the current process report file. If
this option is not used, the process data will overwrite the existing process report file.

ModelSim Reference Manual, v10.1c 195

Commands
project

project
This command is used to perform common operations on projects.
Prerequisites
Some arguments to this command require a project to be opened with either the project new or
project open command. Some argument must be used outside of a simulation session. Please
read the argument descriptions for more information.
Syntax
project [addfile <filename> [<file_type>] [<folder_name>]] | [addfolder <foldername>
[<folder_parent>]] | [calculateorder] | [close] | [compileall [-n]] | [compileorder] |
[compileoutofdate [-n]] | [delete <filename>] | [filenames] | [env] | [history] | [new
<home_dir> <proj_name> [<defaultlibrary>] [<intialini>] [0 | 1]] | [open <project>] |
[removefile <filename>]
Arguments
• addfile <filename> [<file_type>] [<folder_name>]
(optional) Adds the specified file to the current project. Requires a project to be open.
<filename> — (required) The name of an existing file.
<file_type> — (optional) The HDL file type of the file being added. For example do for
a .do file.
<folder_name> — (optional) Places the file in an existing folder created with project
addfolder command. If no folder name is specified the file will be placed in the top
level folder.
• addfolder <foldername> [<folder_parent>]
(optional) Creates a project folder within the project. Requires a project to be open.
<foldername> — (required) Any string.
<folder_parent> — (optional) Places <foldername> in an existing parent folder. If
<folder_parent> is unspecified, <foldername> is placed at the top level.
• calculateorder
(optional) Determines the compile order for the project by compiling each file, then moving
any compiles that fail to the end of the list. This is repeated until there are no more compile
errors.
• close
(optional) Closes the current project.
• compileall [-n]
(optional) Compiles all files in the project using the defined compile order.
-n — (optional) Returns a list of the compile commands this command would execute,
without actually executing the compiles.

196 ModelSim Reference Manual, v10.1c

Commands
project

• compileorder
(optional) Returns the current compile order list.
• compileoutofdate [-n]
(optional) Compiles all files that have a newer date/time stamp than the last time the file was
compiled.
-n — Returns a list of the compile commands this command would execute, without
actually executing the compiles.
• delete <filename>
(optional) Deletes a project file.
<filename> — Any .mpf file.
• filenames
Returns the absolute pathnames of all files contained in the currently open project.
• env
(optional) Returns the current project file and path.
• history
(optional) Lists a history of manipulated projects. Must be used outside of a simulation
session.
• new <home_dir> <proj_name> [<defaultlibrary>] [<intialini>] [0 | 1]
(optional) Creates a new project under a specified home directory with a specified name and
optionally a default library. The name of the work library will default to "work" unless
specified. A new project cannot be created while a project is currently open or a simulation
is in progress.
<home_dir> — The path to the new project directory within the current working
directory.
<proj_name> — Specifies a name for the new project. The file will be saved as an .mpf
file
<defaultlibrary> — Specifies a name for the default library.
<intialini> — An optional modelsim.ini file can be specified as a seed for the project file
by using the initialini option. If initialini is an empty string, then ModelSim uses the
current modelsim.ini file when creating the project. You must specify a default library
if you want to specify initialini.
0 — (default) Copies all library mappings from the specified <initialini> file into the
new project.
1 — Copies library mappings referenced in an "others" clause in the initial .ini file.

ModelSim Reference Manual, v10.1c 197

Commands
project

• open <project>
(optional) Closes any currently opened project and opens a specified project file (must be a
valid .mpf file), making it the current project. Changes the current working directory to the
project's directory. Must be used outside of a simulation session.
• removefile <filename>
(optional) Removes the specified file from the current project.
Examples
• Make /user/george/design/test3/test3.mpf the current project and changes the current
working directory to /user/george/design/test3.
project open /user/george/design/test3/test3.mpf

• Execute current project library build scripts.

project compileall

198 ModelSim Reference Manual, v10.1c

Commands
pwd

pwd
This Tcl command displays the current directory path in the Transcript window.
Syntax
pwd
Arguments
• None

ModelSim Reference Manual, v10.1c 199

Commands
quietly

quietly
This command turns off transcript echoing for the specified command.
Syntax
quietly <command>
Arguments
• <command>
(required) Specifies the command for which to disable transcript echoing. Any results
normally echoed by the specified command will not be written to the Transcript window. To
disable echoing for all commands use the transcript command with the -quietly option.
Related Topics
• transcript

200 ModelSim Reference Manual, v10.1c

Commands
quit

quit
This command exits the simulator.
If you want to stop the simulation using a when command, you must use a stop command within
your when statement, you must not use an exit or a quit command. The stop command acts like
a breakpoint at the time it is evaluated.
Syntax
quit [-f | -force] [-sim] [-code <integer>]
Arguments
• -f | -force
(optional) Quits without asking for confirmation. If omitted, ModelSim asks you for
confirmation before exiting. (The -f and -force arguments are equivalent.)
• -sim
(optional) Unloads the current design in the simulator without exiting ModelSim. All files
opened by the simulation will be closed including the WLF file (vsim.wlf).
• -code <integer>
(optional) Quits the simulation and issues an exit code.
<integer> — This is the value of the exit code. You should not specify an exit code that
already exists in ModelSim. Refer to the section "Exit Codes" in the User’s Manual
for a list of existing exit codes. You can also specify a variable in place of <integer>.
You should always print a message before running the quit -code command to explicitly
state the reason for exiting.
Examples
Refer to the Examples section of the exit command for an example of using the -code argument.
The quit and exit commands behave similarly in this regard.

ModelSim Reference Manual, v10.1c 201

Commands
radix

radix
This command specifies the default radix to be used for the current simulation. Specifying the
command with no argument returns the current radix setting.
The command can be used at any time. The specified radix is used for all commands (force,
examine, change, etc.) as well as for displayed values in the Objects, Locals, Dataflow, List, and
Wave windows, as well as the Source window in the source annotation view.
Alternate methods for changing the default radix:
• In the modelsim.ini file, edit the DefaultRadix variable.
• Choose Simulate > Runtime Options from the main menu, click the Defaults tab,
make your selection in the Default Radix box.
Syntax
radix [-binary | -fpoint | -octal | -decimal | -hexadecimal | -unsigned | -ascii | -time]
[-enumnumeric | -enumsymbolic | -showbase | -symbolic | ]
Arguments
You can abbreviate the following arguments to any length. For example, -dec is equivalent to
-decimal.

• -ascii
(optional) Display a Verilog object as a string equivalent using 8-bit character encoding.
• -binary
(optional) Displays values in binary format.
• -enumnumeric
(optional) Causes Verilog and SystemC enums to be displayed as numbers (formatted by the
current radix). This overrides the default behavior of always showing enums symbolically.
• -enumsymbolic
(optional) Restores the default behavior of displaying Verilog and SystemC enums as
symbols by reversing the action of the -enumnumeric option.
• -fpoint
(optional) Displays values in fixed-point format.
• -decimal
(optional) Displays values in decimal format. You can specify -signed as an alias for this
argument.
• -hexadecimal
(optional) Displays values in hexadecimal format.

202 ModelSim Reference Manual, v10.1c

Commands
radix

• -octal
(optional) Displays values in octal format.
• -time
(optional) Displays values of time for register-based types in Verilog.
• -showbase
(optional) Display the number of bits of the vector and the radix used, where:
binary = b
decimal = d
hexidecimal = h
ASCII = a
time = t
For example, instead of simply displaying a vector value of “31”, a value of “16’h31” may
be displayed to show that the vector is 16 bits wide, with a hexidecimal radix.
• -symbolic
(optional) Displays values in a form closest to their natural form.
• -unsigned
(optional) Displays values in unsigned decimal format.
Related Topics
• User-Defined Radices
• radix define
• radix delete
• radix names
• radix list
• radix signal

ModelSim Reference Manual, v10.1c 203

Commands
radix define

radix define
This command is used to create or modify a user-defined radix. A user definable radix is used to
map bit patterns to a set of enumeration labels. User-defined radices are available for use in the
Wave and List windows or with the examine command.
Syntax
radix define <name> <definition_body> [-color <value>]
Arguments
• <name>
(required) User-specified name for the radix.
• <definition_body>
(required) A list of number pattern, label pairs. The definition body has the form:
{
<numeric-value> <enum-label>,
<numeric-value> <enum-label>
-default <radix_type>
}

A <numeric-value> is any legitimate HDL integer numeric literal. To be more specific:

<base>#<base-integer># --- <base> is 2, 8, 10, or 16
<base>"bit-value" --- <base> is B, O, or X
<integer>
<size>'<base><number> --- <size> is an integer, <base> is b, d, o,
or h.

Refer to the Verilog and VHDL Language Reference Manuals for exact definitions of these
numeric literals.
The comma (,) in the definition body is optional. The <enum-label> is any arbitrary string. It
should surrounded by quotation marks (""), especially if it contains spaces.
The -default entry is optional. If present, it defines the radix to use if a match is not found
for a given value. The -default entry can appear anywhere in the list, it does not have to be
at the end.
• -color <value>
(optional) Designates a color for the waveform and text in the Wave window.
<value> — The color value may be a color name or its hex value (see example below).
Example
• The radix define command used to create a radix called “States,” which will display
state values in the List, Watch, and Wave windows instead of numeric values.
radix define States {
11'b00000000001 "IDLE",

204 ModelSim Reference Manual, v10.1c

Commands
radix define

11'b00000000010 "CTRL",
11'b00000000100 "WT_WD_1",
11'b00000001000 "WT_WD_2",
11'b00000010000 "WT_BLK_1",
11'b00000100000 "WT_BLK_2",
11'b00001000000 "WT_BLK_3",
11'b00010000000 "WT_BLK_4",
11'b00100000000 "WT_BLK_5",
11'b01000000000 "RD_WD_1",
11'b10000000000 "RD_WD_2",
-default hex
}

• The following example illustrates how to specify the radix color:

radix define States {
11'b00000000001 "IDLE" -color yellow,
11'b00000000010 "CTRL" -color #ffee00,
11'b00000000100 "WT_WD_1" -color orange,
11'b00000001000 "WT_WD_2" -color orange,
11'b00000010000 "WT_BLK_1",
11'b00000100000 "WT_BLK_2",
11'b00001000000 "WT_BLK_3",
11'b00010000000 "WT_BLK_4",
11'b00100000000 "WT_BLK_5",
11'b01000000000 "RD_WD_1" -color green,
11'b10000000000 "RD_WD_2" -color green,
-default hex
-defaultcolor white
}

If a pattern/label pair does not specify a color, the normal wave window colors will be
used. If the value of the waveform does not match any pattern, then the -default radix
and -defaultcolor will be used.

ModelSim Reference Manual, v10.1c 205

Commands
radix define

To specify a range of values, wildcards may be specified for bits or characters of the
value. The wildcard character is '?', similar to the iteration character in a Verilog UDP,
for example:
radix define {
6'b01??00 "Write" -color orange,
6'b10??00 "Read" -color green
}

In this example, the first pattern will match "010000", "010100", "011000", and
"011100". In case of overlaps, the first matching pattern is used, going from top to
bottom.
Related Topics
• User-Defined Radices
• radix
• radix delete
• radix names
• radix list
• radix signal

206 ModelSim Reference Manual, v10.1c

Commands
radix delete

radix delete
This command will remove the radix definition from the named radix.
Syntax
radix delete <name>
Arguments
• <name>
(required) Removes the radix definition from the named radix.
Related Topics
• User-Defined Radices
• radix
• radix define
• radix list
• radix names
• radix signal

ModelSim Reference Manual, v10.1c 207

Commands
radix list

radix list
This command will return the complete definition of a radix, if a name is given. If no name is
given, it will list all the defined radices.
Syntax
radix list [<name>]
Arguments
• <name>
(optional) Returns the complete definition of the named radix.
Related Topics
• User-Defined Radices
• radix
• radix define
• radix delete
• radix names
• radix signal

208 ModelSim Reference Manual, v10.1c

Commands
radix names

radix names
This command returns a list of currently defined radix names.
Syntax
radix names
Arguments
None
Related Topics
• User-Defined Radices
• radix
• radix define
• radix delete
• radix list
• radix signal

ModelSim Reference Manual, v10.1c 209

Commands
radix signal

radix signal
This command sets or inspects radix values for the specified signal in the Objects, Locals,
Schematic, and Wave windows.
Note
The intent is for this command to be used for a small number of signals. If the majority of
signals in a design are to use a particular radix value, then set that value as the default
radix with the radix command, and use the radix signal command for the rest.

When no argument is used, the radix signal command returns a list of all signals with a radix.
Syntax
radix signal [<signal_name> [<radix_value>]] [-fpoint <decimal>] [-showbase]
Arguments
• <signal_name>
(optional) Name of the signal for which the radix will be set (if <radix_value> is specified)
or inspected.
• <radix_value>
(optional) Value of the radix to be set for the specified signal. Use empty quotation marks
("") to unset the radix for the specified signal.
• -fpoint <decimal>
(optional) Designates a fixed point radix with “decimal” specifying the number of decimal
places of the radix.
• -showbase
(optional) Display the number of bits of the vector and the radix used, where:
binary = b
decimal = d
hexidecimal = h
ASCII = a
time = t
For example, instead of simply displaying a vector value of “31”, a value of “16'h31” may
be displayed to show that the vector is 16 bits wide, with a hexidecimal radix.
Related Topics
• User-Defined Radices
• radix
• radix define
• radix list
• radix delete

210 ModelSim Reference Manual, v10.1c

Commands
readers

readers
This command displays the names of all readers of the specified object.
The reader list is expressed relative to the top-most design signal/net connected to the specified
object.
The output from the readers command, which is displayed in the Transcript window as a
hypertext link, allows you to right-click to open a drop-down menu and to quickly add signals to
various windows. It includes a "View Declaration" item to open the source definition of the
signal.

Figure 2-4. readers Command Results in Transcript

Syntax
readers <object_name> [-source]
Arguments
• <object_name>
(required) Specifies the name of the signal or net whose readers are to be shown. All signal
or net types are valid. Multiple names and wildcards are accepted.
• -source
(optional) Returns the source file name and line number for each driver of the specified
signal or net. If the source location cannot be determined, the value n/a is returned for that
driver.
Related Topics
• drivers

ModelSim Reference Manual, v10.1c 211

Commands
report

report
This command displays information relevant to the current simulation.
Syntax
report files
report where [ini] [pwd] [transcript] [wlf] [project]
report simulator control
report simulator state
Arguments
• files
Returns a list of all source files used in the loaded design. This information is also available
in the Specified Path column of the Files window.
• where [ini] [pwd] [transcript] [wlf] [project]
Returns a list of configuration files where the arguments limit the list to those files specified.
If specified without arguments, returns a list of all configuration files in the current
simulation.
ini — (optional) Returns the location of the modesim.ini file.
pwd — (optional) Returns the current working directory.
transcript — (optional) Returns the location for saving the transcript file.
wlf — (optional) Returns the current location for saving the .wlf file.
project — (optional) Returns the current location of the project file.
• simulator control
Displays the current values for all simulator control variables.
• simulator state
Displays the simulator state variables relevant to the current simulation.
Examples
• Display configuration file information
report where

Returns:
# INI {modelsim.ini}
# PWD ./Testcases/
# Transcript transcript
# WLF vsim.wlf
# Project {}

• Display all simulator control variables.

212 ModelSim Reference Manual, v10.1c

Commands
report

report simulator control

Returns:
# UserTimeUnit = ns
# RunLength =
# IterationLimit = 5000
# BreakOnAssertion = 3
# DefaultForceKind = default
# IgnoreNote = 0
# IgnoreWarning = 0
# IgnoreError = 0
# IgnoreFailure = 0
# IgnoreSVAInfo= 0
# IgnoreSVAWarning = 0
# IgnoreSVAError = 0
# IgnoreSVAFatal = 0
# CheckpointCompressMode = 1
# NumericStdNoWarnings = 0
# StdArithNoWarnings = 0
# PathSeparator = /
# DefaultRadix = symbolic
# DelayFileOpen = 1
# WLFFilename = vsim.wlf
# WLFTimeLimit = 0
# WLFSizeLimit = 0

• Display all simulator state variables. Only the variables that relate to the design being
simulated are displayed:
report simulator state

Returns:
# now = 0.0
# delta = 0
# library = work
# entity = type_clocks
# architecture = full
# resolution = 1ns

Viewing preference variables

Preference variables have more to do with the way things look (but not entirely) rather than
controlling the simulator. You can view preference variables from the Preferences dialog box.
Select Tools > Edit Preferences (Main window).
Related Topics
• modelsim.ini Variables
• Simulator GUI Preferences

ModelSim Reference Manual, v10.1c 213

Commands
restart

restart
This command reloads the design elements and resets the simulation time to zero. Only design
elements that have changed are reloaded. (Note that SDF files are always reread during a
restart.)
• If no design is loaded, the restart command produces a message to that effect and takes
no further action.
• If a simulation is loaded, the restart command restarts the simulation.
• If multiple datasets are open, including a simulation, the environment is changed to the
simulation context and the simulation is restarted.
Shared libraries are handled as follows during a restart:
• Shared libraries that implement VHDL foreign architectures only are reloaded at each
restart when the architecture is elaborated (unless vsim -keeploaded is used).
• Shared libraries loaded from the command line (-foreign and -pli options) and from the
Veriuser entry in the modelsim.ini file are reloaded (unless vsim -keeploaded is used).
• Shared libraries that implement VHDL foreign subprograms remain loaded (they are not
reloaded) even if they also contain code for a foreign architecture.
You can configure defaults for the restart command by setting the DefaultRestartOptions
variable in the modelsim.ini file. Refer to “Restart Command Defaults”.
To handle restarts with Verilog PLI applications, you need to define a Verilog user-defined task
or function, and register a misctf class of callback. To handle restarts with Verilog VPI
applications, you need to register reset callbacks. To handle restarts with VHDL FLI
applications, you need to register restart callbacks. Refer to “Verilog Interfaces to C” for more
information on the Verilog PLI/VPI/DPI and the ModelSim FLI Reference for more information
on the FLI.
Syntax
restart [-force] [-nobreakpoint] [-nolist] [-nolog] [-nowave]
Arguments
• -force
(optional) Specifies that the simulation will be restarted without requiring confirmation in a
popup window.
• -nobreakpoint
(optional) Specifies that all breakpoints will be removed when the simulation is restarted
where the default is for all breakpoints to be reinstalled after the simulation is restarted.

214 ModelSim Reference Manual, v10.1c

Commands
restart

• -nolist
(optional) Specifies that the current List window environment will not be maintained after
the simulation is restarted where the default is for all currently listed HDL objects and their
formats to be maintained.
• -nolog
(optional) Specifies that the current logging environment will not be maintained after the
simulation is restarted where the default is for all currently logged objects to continue to be
logged.
• -nowave
(optional) Specifies that the current Wave window environment will not be maintained after
the simulation is restarted where the default is for all objects displayed in the Wave window
to remain in the window with the same format.
Related Topics
• vsim

ModelSim Reference Manual, v10.1c 215

Commands
resume

resume
This command is used to resume execution of a macro (DO) file after a pause command or a
breakpoint.
This command may be input manually or placed in an onbreak command string. (Placing a
resume command in a bp command string does not have this effect.) The resume command can
also be used in an onerror command string to allow an error message to be printed without
halting the execution of the macro file.
Syntax
resume
Arguments
• None
Related Topics
• abort
• do
• onbreak
• onerror
• pause
• Useful Commands for Handling
Breakpoints and Errors

216 ModelSim Reference Manual, v10.1c

Commands
run

run
This command advances the simulation by the specified number of timesteps.
Syntax
run [<timesteps>[<time_units>]] | -all | -continue | -init | -next | -over |
-step [-inst <full_path>] [-out] [-over] [-this "this==<class_handle>"]]
Arguments
• No arguments
Runs the simulation for the default time (100 ns).
You can change the default <timesteps> and <time_units> in the GUI with the Run Length
toolbar box in the Simulate toolbar or from the modelsim.ini file: RunLength and
UserTimeUnit variables.
• <timesteps>[<time_units>]
(optional) Specifies the number of timesteps for the simulation to run. The number may be
fractional, or may be specified as absolute by preceding the value with the character @.
<time_units> — Any valid time unit: fs, ps, ns, us, ms, or sec where the default is to use
the current time unit.
• -all
(optional) Causes the simulator to run the current simulation forever, or until it hits a
breakpoint or specified break event.
• -continue
(optional) Continues the last simulation run after a run -step, run -step -over command or a
breakpoint. A run -continue command may be input manually or used as the last command
in a bp command string.
• -final
(optional) Instructs the simulator to run all final blocks then exit the simulation.
• -init
(optional) Initializes non-trivial static SystemVerilog variables before beginning the
simulation, for example, expressions involving other variables and function calls,. This
could be useful for when you want to initialize values before executing any force, examine,
or bp commands.
You cannot use run -init after any other run commands or if you have specified vsim
-runinit on the command line because all variables would have been initialized by that
point.
• -next
(optional) Causes the simulator to run to the next event time.

ModelSim Reference Manual, v10.1c 217

Commands
run

• -step
(optional) Steps the simulator to the next HDL . Current values of local HDL variables may
be observed at this time using the Locals window. You can specify the following arguments
when you use -step:
-inst <full_path>
(optional) Instructs the simulation to step into a specific instance, process, or thread.
<full_path> — Specifies the full path to an instance, process or thread.
-out
(optional) Instructs the simulation to step out of the current function or procedure and
return to the caller.
-over
(optional) Directs ModelSim to run VHDL procedures and functions, Verilog tasks
and functions but to treat them as simple statements instead of entering and tracing
them line by line.
You can use the -over argument to skip over a VHDL procedures or functions,
Verilog task or functions. When a wait statement or end of process is encountered,
time advances to the next scheduled activity. ModelSim then updates the Process and
Source windows to reflect the next activity.
-this "this==<class_handle>"
(optional) Instructs the simulation to step into a method of a SystemVerilog class
when “this” refers to the specified class handle. To obtain the handle of the class, use
the examine -handle command.
<class_handle> — Specifies a SystemVerilog class. Note that you must use
quotation marks (" ") with this argument.
• -over
(optional) Directs ModelSim to run VHDL procedures and functions, Verilog tasks and
functions but to treat them as simple statements instead of entering and tracing them line by
line.
Examples
• Advance the simulator 1000 timesteps.
run 1000

• Advance the simulator the appropriate number of timesteps corresponding to 10.4

milliseconds.
run 10.4 ms

• Advance the simulator to timestep 8000.

run @8000

218 ModelSim Reference Manual, v10.1c

Commands
run

• Advance the simulator into the instance /top/p.

run -step -inst /top/p

Related Topics
• Simulate Toolbar

ModelSim Reference Manual, v10.1c 219

Commands
runStatus

runStatus
This command returns the current state of your simulation to stdout after issuing a run or step
command.
Syntax
runStatus [-full]
Arguments
• -full
(optional) Appends additional information to the output of the runStatus command.
Returns
Table 2-3 (runStatus Command States) and Table 2-4 (runStatus -full Command Information)
show outputs of the runStatus command.

Table 2-3. runStatus Command States

State Description
ready The design is loaded and is ready to run.
break The simulation stopped before completing the requested run.
error The simulation stopped due to an error condition.
loading The simulation is currently elaborating.
nodesign There is no design loaded.
checkpoint A checkpoint is being created, do not interrupt this process.
cready The design is loaded and is ready to run in C debug mode.
initializing The user interface initialization is in progress.

Table 2-4. runStatus -full Command Information

-full Information Description
bkpt stopped at breakpoint
bkpt_builtin stopped at breakpoint on builtin process
end reached end of requested run
fatal_error encountered fatal error (such as, divide by 0)
iteration_limit iteration limit reached, possible feedback loop
silent_halt mti_BreakSilent() called,
step run -step completed
step_builtin run -step completed on builtin process

220 ModelSim Reference Manual, v10.1c

Commands
runStatus

Table 2-4. runStatus -full Command Information (cont.)

-full Information Description
step_wait_suspend run -step completed, time advanced.
user_break run interrupted do to break-key or ^C (SIGINT)
user_halt mti_Break() called.
user_stop stop or finish requested from vpi, stop command, etc.
gate_oscillation Verilog gate iteration limit reached.
simulation_stop pli stop_simulation() called.

ModelSim Reference Manual, v10.1c 221

Commands
searchlog

searchlog
This command searches one or more of the currently open logfiles for a specified condition.
It can be used to search for rising or falling edges, for signals equal to a specified value, or for
when a generalized expression becomes true.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
searchlog [-command <cmd>] [-count <n>] [-deltas] [-endtime <time> [<unit>]] [-env <path>]
[-event <time>] [-expr {<expr>}] [-reverse] [-rising | -falling | -anyedge]
[-startDelta <num>] [-value <string>] <startTime> [<unit>] <pattern>
Description
If at least one match is found, it returns the time (and, optionally, delta) at which the last match
occurred and the number of matches found, in a Tcl list:
{{<time>} <matchCount>}

where <time> is in the format <number> <unit>. If the -deltas option is specified, the delta of
the last match is also returned:
{{<time>} <delta> <matchCount>}

If no matches are found, a TCL_ERROR is returned. If one or more matches are found, but less
than the number requested, it is not considered an error condition, and the time of the farthest
match is returned, with the count of the matches found.
Arguments
• -command <cmd>
(optional) Specifies a Tcl command that will be called for each event on the specified signal.
<cmd> — A Tcl command that receives four arguments and returns one of three values:
"continue", "stop", or "" (empty).
The command will be passed four arguments: the reason for the call, the time of the event,
the delta for the event, and the value. The reason value will be one of WLF_STARTLOG,
WLF_ENDLOG, WLF_EVENT, or WLF_WAKEUP. The function is expected to return
"continue", "stop", or "" (empty). If "continue" or "" (empty) is returned, the search
continues, making additional callbacks as necessary. If "stop" is returned, the search stops
and control is returned to the caller of the searchlog command.
Only searching for a single signal is supported.
• -count <n>
(optional) Specifies to search for the nth occurrence of the match condition.
<n> — Any positive integer.

222 ModelSim Reference Manual, v10.1c

Commands
searchlog

• -deltas
(optional) Indicates to test for a match on simulation delta cycles. Otherwise, matches are
only tested for at the end of each simulation time step.
• -endtime <time> [<unit>]
(optional) Specifies the simulation time at which to end the search. By default no end time is
specified.
<time> — Specified as an integer or decimal number. Current simulation units are the
default unless specifying <unit>.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid VHDL time units are: fs, ps,
ns, us, ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and
<unit> within curly braces ({}).
• -env <path>
(optional) Indicates to test for a match on simulation delta cycles. Otherwise, matches are
only tested for at the end of each simulation time step.ath> — A path to a design region.
Wildcards not allowed.
• -event <time>
(optional) Indicates to test for a match on a simulation event. Otherwise, matches are only
tested for at the end of each simulation time step.
• -expr {<expr>}
(optional) Specifies a search for a general expression of signal values and simulation time.
searchlog will search until the expression evaluates to true.
{<expr>} — An expression that evaluates to a boolean true. See
GUI_expression_format for the format of the expression.
• -reverse
(optional) Specifies to search backwards in time from <startTime>.
• -rising
(optional) Specifies a search for rising edge on a scalar signal. This option is ignored for
compound signals.
• -falling
(optional) Specifies a search for falling edge on a scalar signal. This option is ignored for
compound signals.
• -anyedge
(optional) Specifies a search for a rising or falling edge on a scalar signal. This option is
ignored for compound signals. (default)
• -startDelta <num>
(optional) Indicates a simulation delta cycle on which to start.

ModelSim Reference Manual, v10.1c 223

Commands
searchlog

<num> — Any positive integer.

• -value <string>
(optional) Specifies a match of a single scalar or compound signal against a specified string.
<string> — Specifies a string to be matched.
• <startTime> [<unit>]
(required) Specifies the simulation time at which to start the search. The time is specified as
an integer or decimal number. Must be placed immediately before the <pattern> argument.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid VHDL time units are: fs, ps,
ns, us, ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and
<unit> within curly braces ({}).
• <pattern>
(Required unless the -expr argument is used.) Specifies one or more signal names or
wildcard patterns of signal names to search on. Must be specified as the final argument to
the searchlog command.
Related Topics
• virtual signal
• virtual log
• virtual nolog
• GUI_expression_format

224 ModelSim Reference Manual, v10.1c

Commands
see

see
This command displays the specified number of source file lines around the current execution
line and places a marker to indicate the current execution line. If specified without arguments,
five lines will be displayed before and four lines after.
Syntax
see [<n> | <pre> <post>]
Arguments
• <n>
(optional) Designates the number of lines to display before and after the current execution
line.
• <pre>
(optional) Designates the number of lines to display before the current execution line.
• <post>
(optional) Designates the number of lines to display after the current execution line.
Example
• Display 2 lines before and 5lines after the current execution line.
see 2 5

Returns:

# 92 :
# 93 : if (verbose) $display("Read/Write test done");
# ->94 : $stop(1);
# 95 : end
# 96 : end
# 97 :
# 98 : or2 i1 (
# 99 : .y(t_set),

ModelSim Reference Manual, v10.1c 225

Commands
setenv

setenv
This command changes or reports the current value of an environment variable. The setting is
valid only for the current ModelSim session.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
setenv <varname> [<value>]
Arguments
• <varname>
(required) The name of the environment variable you wish to set or check. Must be specified
as the first argument to the setenv command.
• <value>
(optional) The new value for <varname>. If you do not specify a value, ModelSim reports
the variable’s current value.
Related Topics
• unsetenv
• printenv

226 ModelSim Reference Manual, v10.1c

Commands
shift

shift
This command shifts macro parameter values left one place, so that the value of parameter \$2 is
assigned to parameter \$1, the value of parameter \$3 is assigned to \$2, and so on. The previous
value of \$1 is discarded.
The shift command and macro parameters are used in macro files. If a macro file requires more
than nine parameters, they can be accessed using the shift command.
To determine the current number of macro parameters, use the argc variable.
Syntax
shift
Arguments
• None
Description
For a macro file containing nine macro parameters defined as $1 to $9, one shift command
shifts all parameter values one place to the left. If more than nine parameters are named, the
value of the tenth parameter becomes the value of $9 and can be accessed from within the
macro file.
Related Topics
• do

ModelSim Reference Manual, v10.1c 227

Commands
show

show
This command lists HDL objects and subregions visible from the current environment.
The objects listed include:
• VHDL — signals, processes, constants, variables, and instances.
• Verilog — nets, registers, tasks, functions, instances, variables, and memories.
The show command returns formatted results to stdout. To eliminate formatting (to use the
output in a Tcl script), use the Show form of the command instead.
Syntax
show [-all] [<pathname>]
Arguments
• -all
(optional) Displays all names at and below the specified path recursively.
• <pathname>
(optional) Specifies the pathname of the environment for which you want the objects and
subregions to be listed; if omitted, the current environment is assumed.
Examples
• List the names of all the objects and subregion environments visible in the current
environment.
show

• List the names of all the objects and subregions visible in the environment named /uut.
show /uut

• List the names of all the objects and subregions visible in the environment named
sub_region which is directly visible in the current environment.
show sub_region

• List the names of all the objects and subregions visible in all top-level environments.
show -all /

Related Topics

• environment
• find

228 ModelSim Reference Manual, v10.1c

Commands
simstats

simstats
This command returns performance-related statistics about elaboration and simulation. The
statistics measure the simulation kernal process (vsimk) for a single invocation of vsim. If you
invoke vsim a second time, or restart the simulation, the current statistics are discarded and new
values are collected.
If executed without arguments, the command returns a list of pairs similar to the following:
{{elab memory} 0} {{elab working set} 7245824} {{elab time} 0.942645}
{{elab cpu time} 0.190274} {{elab context} 0} {{elab page faults} 1549}
{memory 0} {{working set} 0} {time 0} {{cpu time} 0} {context 0}
{{page faults} 0}

The elaboration statistics are measured one time at the end of elaboration. The simulation
memory statistics are measured at the time you invoke simstats. The simulation time statistics
are updated at the end of each run command. See the arguments below for descriptions of each
statistic.
Units for time values are in seconds. Units for memory values vary by platform:
• For SunOS and Linux, the memory size is reported in Kbytes
• For Windows, the memory size is reported in bytes.
Some of the values may not be available on all platforms and other values may be approximates.
Different operating systems report these numbers differently.
Syntax
simstats [memory | working | time | cpu | context | faults]
Arguments
• memory
(optional) Returns the amount of virtual memory that the OS has allocated for vsimk.
• working
(optional) Returns the portion of allocated virtual memory that is currently being used by
vsimk. If this number exceeds the actual memory size, you will encounter performance
degradation.
• time
(optional) Returns the cumulative “wall clock” time of all run commands.
• cpu
(optional) Returns the cumulative processor time of all run commands. Processor time
differs from wall clock time in that processor time is only counted when the cpu is actually
running vsimk. If vsimk is swapped out for another process, cpu time does not increase.

ModelSim Reference Manual, v10.1c 229

Commands
simstats

• context
(optional) Returns the number of context swaps (vsimk being swapped out for another
process) that occurred during all run commands.
• faults
(optional) Returns the number of page faults that occurred during all run commands.

230 ModelSim Reference Manual, v10.1c

Commands
stack down

stack down
This command moves down the call stack.
If invoked without arguments, the command moves down the call stack by 1 level. The Locals
window displays local variables at the level.
Syntax
stack down [n]
Arguments
• n
(optional) Moves down the call stack by n levels. The default value is 1 level.
Related Topics
stack frame stack tb
stack level stack up

ModelSim Reference Manual, v10.1c 231

Commands
stack frame

stack frame
This command selects the specified call frame.
Syntax
stack frame <n>
Arguments
• <n>
Selects call frame number n. The currently executing frame is zero (also called the
innermost) frame, frame one is the frame that called the innermost, and so on. The highest
numbered frame is that of main.
Related Topics
stack down stack tb
stack level stack up

232 ModelSim Reference Manual, v10.1c

Commands
stack level

stack level
This command reports the current call frame number.
Syntax
stack level
Arguments
• None

Related Topics
stack down stack tb
stack frame stack up

ModelSim Reference Manual, v10.1c 233

Commands
stack tb

stack tb
The stack tb command is an alias for the tb command.
Refer to the tb command for a complete syntax description.

234 ModelSim Reference Manual, v10.1c

Commands
stack up

stack up
This command moves up the call stack.
If invoked without arguments, the command moves up the call stack by 1 level. The Locals
window displays local variables at the level.
Syntax
stack up [n]
Arguments
• n
(optional) Moves up the call stack by n levels. The default value is 1 level.
Related Topics
stack down stack level
stack frame stack tb

ModelSim Reference Manual, v10.1c 235

Commands
status

status
This command lists summary information about currently interrupted macros.
If invoked without arguments, the command lists the filename of each interrupted macro, the
line number at which it was interrupted, and prints the command itself. It also displays any
onbreak or onerror commands that have been defined for each interrupted macro.
Syntax
status [file | line]
Arguments
• file
(optional) Reports the file pathname of the current macro.
• line
(optional) Reports the line number of the current macro.
Examples
The transcript below contains examples of resume, and status commands.
VSIM(paused)> status
# Macro resume_test.do at line 3 (Current macro)
# command executing: "pause"
# is Interrupted
# ONBREAK commands: "resume"
# Macro startup.do at line 34
# command executing: "run 1000"
# processing BREAKPOINT
# is Interrupted
# ONBREAK commands: "resume"
VSIM(paused)> resume
# Resuming execution of macro resume_test.do at line 4

Related Topics
• abort
• do
• pause
• resume

236 ModelSim Reference Manual, v10.1c

Commands
step

step
The step command is an alias for the run command with the -step switch.
Refer to the run command for a complete syntax description.

ModelSim Reference Manual, v10.1c 237

Commands
stop

stop
This command is used with the when command to stop simulation in batch files.
The stop command has the same effect as hitting a breakpoint. The stop command may be
placed anywhere within the body of the when command.
Syntax
stop [-sync]
Arguments
• -sync
(optional) Stops the currently running simulation at the next time step.
Description
Use run -continue to continue the simulation run, or the resume command to continue macro
execution. If you want macro execution to resume automatically, put the resume command at
the top of your macro file:
onbreak {resume}

Note
If you want to stop the simulation using a when command, you must use a stop command
within your when statement. DO NOT use an exit command or a quit command. The stop
command acts like a breakpoint at the time it is evaluated.

Related Topics
• bp
• resume
• run
• when

238 ModelSim Reference Manual, v10.1c

Commands
suppress

suppress
This command prevents one or more specified messages from displaying. You cannot suppress
Fatal or Internal messages. The suppress command used without arguments returns the
message numbers of all suppressed messages.
Edit the suppress variable in the modelsim.ini file to set a permanent default. Refer to
“Changing Message Severity Level” for more information.
Syntax
suppress [-clear <msg_number>[,<msg_number>,...]] [<msg_number>[,<msg_number>,…]]
[<code_string>[, <code_string>,...]]
Arguments
• -clear <msg_number>[,<msg_number>,...]
(optional) Clears suppression of one or more messages identified by message number.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• <msg_number>[,<msg_number>,...]
(optional) A number identifying the message to be suppressed. Multiple message numbers
are specified as a comma separated list.
• <code_string>[, <code_string>,...]
(optional) A string identifier of the message to be suppressed. Disables warning messages in
the category specified by <CODE>. Warnings that can be disabled include the <CODE>
name in square brackets in the warning message.
Examples
• Return the message numbers of all suppressed messages:
suppress

• Suppress messages by message number:

suppress 8241,8242,8243,8446,8447

• Suppress messages by numbers and code categories:

suppress 8241,TFMPC,CNNODP,8446,8447

• Clear message suppression for the designated messages:

suppress -clear 8241,8242

• Return the message numbers of all suppressed messages and clear suppression for all:
suppress -clear [suppress]

ModelSim Reference Manual, v10.1c 239

Commands
tb

tb
This (traceback) command (traceback) displays a stack trace for the current process in the
Transcript window. This lists the sequence of HDL function calls that have been entered to
arrive at the current state for the active process.
Syntax
tb
Arguments
• None

240 ModelSim Reference Manual, v10.1c

Commands
Time

Time
These commands allow you to perform comparisons between, operations on, and conversions
of, time values.
When [unit] is left unspecified the commands assume the current simulation time unit, as
defined by the Resolution variable in the modelsim.ini file or the vsim -t command. Units of
time (ns, us, and so forth) can be specified independently for each <time[1 | 2]> specified for
most of the commands. See the description of each command and examples for more
information.
Arguments to this command are order dependent. Follow the order specified in the Syntax for
each command.
Syntax
eqTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> and <time2> are equal.
neqTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> and <time2> are not equal.
ltTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> is less than <time2>.
gtTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> is greater than <time2>.
lteTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> is less than or equal to <time2>.
gteTime <time1>[unit] <time2>[unit]
Returns a 1 (true) or 0 (false) if <time1> is greater than or equal to <time2>.
addTime <time1>[unit] <time2>[unit]
Returns the sum of adding <time1> to <time2>
subTime <time1>[unit] <time2>[unit]
Returns the value of subtracting <time2> from <time1>
mulTime <time1>[unit] <integer>
Returns the value of multiplying <time1> by an <integer>
divTime <time1>[unit] <time2>[unit]
Returns an integer, that is the value of dividing <time1> by <time2>. Specifying 0 for
<time2> results in an error.
intToTime <high_32bit_int> <low_32bit_int>

ModelSim Reference Manual, v10.1c 241

Commands
Time

Returns a 64-bit time value based on two 32-bit parts of a 64-bit integer. This command is
useful when you’ve performed an integer calculation that results in a 64-bit value and need
to convert it to a time unit.
scaleTime <time1>[unit] <scale_factor>
Returns a time value scaled by a real number and truncated to the current time resolution.
RealToTime <real>
Returns a time value equivalent to the specified real number and truncated to the current
time resolution.
validTime <time>
Returns a 1 (true) or 0 (false) if the given string is a valid time for use with any of these
Time calculations.
formatTime {+ | -} commas | {+ | -}nodefunit | {+ | -}bestunits
Sets display properties for time values.
Arguments
• <time1>[unit] ...
<time> — Specified as an integer or decimal number. Current simulation units are the
default unless specifying <unit>.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid VHDL time units are:
fs — femtosecond (10-15 seconds)
ps — picosecond (10-12 seconds)
ns — nanosecond (10-9 seconds)
us — microsecond (10-6 seconds)
ms — millisecond (10-3 seconds)
sec — second
min — minute (60 seconds)
hr — hour (3600 seconds)
Note that if you put a space between the values, you must enclose the argument in braces
({ }) or quotation marks ( " " ).
• <high_32bit_int> | <low_32bit_int>
<high_32bit_int> — The "high" part of the 64-bit integer.
<low_32bit_int> — The "low" part of the 64-bit integer.
• <scale_factor> — a real number to be used as scaling factor. Common values can include:
0.25, 0.5, 1.5, 2, 10, 100

242 ModelSim Reference Manual, v10.1c

Commands
Time

• {+ | -} commas — controls whether commas are displayed in time values.

+commas — time values include commas
-commas — time values do not include commas
• {+ | -}nodefunit — controls whether time values display time units
+nodefunit — time values do not include time units and will be in current time
resolution
-nodefunit — time values may include time units
• {+ | -}bestunits — controls whether time values display the largest possible time unit, for
example 8 us instead of 8,000 ns.
+bestunits — time values display the largest possible time unit
-bestunits — time values display the default time unit
Examples
>ltTime 100ns 1ms

Returns:
# 1

>addTime {1545 ns} {455 ns}

Returns:
# 2 us

>gteTime "1000 ns" "1 us"

Returns:
# 1

>divTime 1us 10ns

Returns:
# 100

>formatTime +bestunit

Returns:
# -commas -nodefunit +bestunits

>scaleTime 3ms 1000

Returns:
# 3 sec

>RealToTime 1.345e04

Returns:
# 13450 ns

ModelSim Reference Manual, v10.1c 243

Commands
transcript

transcript
This command controls echoing of commands executed in a macro file.
If no option is specified, the current setting is reported.
Syntax
transcript [on | off | -q | quietly]
Arguments
• on
(optional) Specifies that commands in a macro file will be echoed to the Transcript window
as they are executed.
• off
(optional) Specifies that commands in a macro file will not be echoed to the Transcript
window as they are executed.
• -q
(optional) Returns "0" if transcripting is turned off or "1" if transcripting is turned on.
Useful in a Tcl conditional expression.
• quietly
(optional) Turns off the transcript echo for all commands. To turn off echoing for individual
commands see the quietly command.
Examples
• Commands within a macro file will be echoed to the Transcript window as they are
executed.
transcript on

• If issued immediately after the previous example, the message:

transcript

Returns
Macro transcripting is turned ON.

Related Topics
• Transcript Window
• echo

244 ModelSim Reference Manual, v10.1c

Commands
transcript file

transcript file
This command sets or queries the current PrefMain(file) Tcl preference variable. You can use
this command to clear a transcript in batch mode or to limit the size of a transcript file. It offers
an alternative to setting the PrefMain(file) Tcl preference variable through the GUI.
Syntax
transcript file [<filename>]
Arguments
• <filename>
(optional) Specifies a name for the transcript file. Wildcard characters are allowed, and
“stdout” or “stderr” are valid file names. If you specify a new file, the existing transcript file
is closed and a new transcript file opened. If you specify an empty string (""), the existing
file is closed and no new file is opened. If you don’t specify this argument, the current
filename is returned.
Note
You can prevent overwriting older transcript files by including a pound sign (#) in
<filename> when <filename> is a repeated string. The simulator replaces the pound
character (#) with the next available sequence number when saving a new transcript file.

Examples
• Close the current transcript file and stops writing data to the file. This is a method for
reducing the size of your transcript.
transcript file ""

• Close the current transcript file named trans1.txt and open a new transcript file,
incrementing the file name by 1.
transcript file trans#.txt

Closes trans1.txt and opens trans2.txt.

• This series of commands results in the transcript containing only data from the second
millisecond of the simulation. The first transcript file command closes the transcript so
no data is being written to it. The second transcript file command opens a new
transcript and records data from 1 ms to 2 ms.
transcript file ""
run 1 ms
transcript file transcript
run 1 ms

ModelSim Reference Manual, v10.1c 245

Commands
transcript file

Related Topics
• "Creating a Transcript File" • transcript path
• "Setting Preference Variables from the • transcript sizelimit
GUI"
• Transcript Window

246 ModelSim Reference Manual, v10.1c

Commands
transcript path

transcript path
This command returns the full pathname to the current transcript file.
Syntax
transcript path
Arguments
• None
Related Topics
• "Creating a Transcript File" • “Transcript Window”
• "Setting Preference Variables from the • transcript file
GUI"

ModelSim Reference Manual, v10.1c 247

Commands
transcript sizelimit

transcript sizelimit
This command sets or queries the current preference value for the transcript fileSizeLimit value.
If the size limit is reached, the transcript file is saved and simulation continues.
Syntax
transcript sizelimit [<size>]
Arguments
• <size>
(optional) Specifies the size, in KB, of the transcript file where the default is 0 or unlimited.
The actual file size may be larger by as much as one buffer size (usually about 4k),
depending on the operating system default buffer size and the size of the messages written
to the transcript.
Note
You can set the size of the transcript file with the $PrefMain (fileSizeLimit) Tcl variable
in the Preferences dialog. Refer to "Setting Preference Variables from the GUI" for more
information.

Related Topics
• "Creating a Transcript File" • “Transcript Window”
• "Setting Preference Variables from the • transcript file
GUI"

248 ModelSim Reference Manual, v10.1c

Commands
tssi2mti

tssi2mti
This command is used to convert a vector file in TSSI Format into a sequence of force and run
commands.
The stimulus is written to the standard output.
The source code for tssi2mti is provided in the examples directory as:
<install_dir>/examples/tssi2mti/tssi2mti.c

Syntax
tssi2mti <signal_definition_file> [<sef_vector_file>]
Arguments
• <signal_definition_file>
(required) Specifies the name of the TSSI signal definition file describing the format and
content of the vectors.
• <sef_vector_file>
(optional) Specifies the name of the file containing vectors to be converted. If none is
specified, standard input is used.
Examples
• The command will produce a do file named trigger.do from the signal definition file
trigger.def and the vector file trigger.sef.
tssi2mti trigger.def trigger.sef > trigger.do

• This example is the same as the previous one, but uses the standard input instead.
tssi2mti trigger.def < trigger.sef > trigger.do

Related Topics
• force
• run
• write tssi

ModelSim Reference Manual, v10.1c 249

Commands
ui_VVMode

ui_VVMode
This command specifies behavior when encountering UI registration calls used by verification
packages, such as AVM or OVM. Returns the current setting when specifies without an
argument.
Syntax
ui_VVMode [full | logclass | logobj | nolog | off ]
Arguments
• full
(optional) Enables the context registration of the UI registration call and automatically logs
both the class type and the registered object to the WLF file.
• logclass
(optional) Enables the context registration of the UI registration call and automatically logs
the class type of the registered object to the WLF file.
• logobj
(optional) Enables the context registration of the UI registration call and automatically logs
the registered object to the WLF file
• nolog
(optional) Enables the context registration of the UI registration call, but does not
automatically log the registration to the WLF file. (default)
• off
(optional) Disables context registration and automatic logging when encountering UI
registration calls.
Description
UI registration calls, Verilog system tasks specific to this product, are typically included in
verification packages such as AVM and OVM so that key information about the packages is
available when debugging the simulation. The UI registration calls include:

• $ui_VVInstallInst() — Defines a region in the context tree, which will appear in the
Structure window.
• $ui_VVInstallObj() — Adds an object to the defined parent, which will appear in the
Objects window when the parent instance is selected in the Structure window.
• $ui_VVInstallPort() — Adds a port that is an object that connects to another component,
which will appear in the Objects window when the parent instance is selected in the
Structure window.
• $ui_VVSetFilter() — Specifies which class properties should not be shown in the GUI.

250 ModelSim Reference Manual, v10.1c

Commands
ui_VVMode

• $ui_VVSetAllow() — Specifies which class properties should be retained that were

filtered out with $ui_VVSetFilter.

ModelSim Reference Manual, v10.1c 251

Commands
unsetenv

unsetenv
This command deletes an environment variable. The deletion is not permanent – it is valid only
for the current ModelSim session.
Syntax
unsetenv <varname>
Arguments
• <varname>
(required) The name of the environment variable you wish to delete.
Related Topics
• setenv
• printenv

252 ModelSim Reference Manual, v10.1c

Commands
vcd add

vcd add
This command adds the specified objects to a VCD file.
The allowed objects are Verilog nets and variables and VHDL signals of type bit, bit_vector,
std_logic, and std_logic_vector (other types are silently ignored). The command works with
mixed HDL designs.
All vcd add commands must be executed at the same simulation time. The specified objects are
added to the VCD header and their subsequent value changes are recorded in the specified VCD
file. By default all port driver changes and internal variable changes are captured in the file.
You can filter the output using arguments detailed below.
Related Verilog tasks: $dumpvars, $fdumpvars
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
vcd add [-dumpports] [-file <filename>] [[-in] [-out] [-inout] | [-ports]] [-internal]
[-r | -r -optcells] <object_name> ...
Arguments
• -dumpports
(optional) Specifies port driver changes to be added to an extended VCD file. When the vcd
dumpports command cannot specify all port driver changes that will appear within the
VCD file, multiple vcd add -dumpports commands can be used to specify additional port
driver changes.
• -file <filename>
(optional) Specifies the name of the VCD file. This option should be used only when you
have created multiple VCD files using the vcd files command.
<filename> — A .vcd file.
• -in
(optional) Includes only port driver changes from ports of mode IN.
• -out
(optional) Includes only port driver changes from ports of mode OUT.
• -inout
(optional) Includes only port driver changes from ports of mode INOUT.
• -ports
(optional) Includes only port driver changes. Excludes internal variable or signal changes.
• -internal
(optional) Includes only internal variable or signal changes. Excludes port driver changes.

ModelSim Reference Manual, v10.1c 253

Commands
vcd add

• -r | -r -optcells
(optional) Specifies that signal and port selection occurs recursively into subregions. If
omitted, included signals and ports are limited to the current region. When -r is used with
-optcells it allows Verilog optimized cell ports to be visible when using wildcards. By
default Verilog optimized cell ports are not selected even if they match the specified
wildcard pattern.
• <object_name> ...
(required) Specifies the Verilog or VHDL object or objects to add to the VCD file. Multiple
objects may be specified by separating names with spaces. Wildcards are accepted. Must be
specified as the final argument to the vcd add command.
Related Topics
• vcd checkpoint • vcd files
• vcd comment • vcd flush
• vcd dumpports • vcd limit
• vcd dumpportsall • vcd off
• vcd dumpportsflush • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

254 ModelSim Reference Manual, v10.1c

Commands
vcd checkpoint

vcd checkpoint
This command dumps the current values of all VCD variables to the specified VCD file. While
simulating, only value changes are dumped.
Related Verilog tasks: $dumpall, $fdumpall
Syntax
vcd checkpoint [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Related Topics
• vcd add • vcd files
• vcd comment • vcd flush
• vcd dumpports • vcd limit
• vcd dumpportsall • vcd off
• vcd dumpportsflush • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

ModelSim Reference Manual, v10.1c 255

Commands
vcd comment

vcd comment
This command inserts the specified comment in the specified VCD file.
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
vcd comment <comment string> [<filename>]
Arguments
• <comment string>
(required) Comment to be included in the VCD file. Must be enclosed by double quotation
marks or curly braces. Must be specified as the first argument to the vcd comment
command.
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd dumpports • vcd limit
• vcd dumpportsall • vcd off
• vcd dumpportsflush • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

256 ModelSim Reference Manual, v10.1c

Commands
vcd dumpports

vcd dumpports
This command creates a VCD file that includes port driver data.
By default all port driver changes are captured in the file. You can filter the output using
arguments detailed below. Related Verilog task: $dumpports
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
vcd dumpports [-compress] [-direction] [-file <filename>] [-force_direction] [-in] [-out] [-
inout]
[-no_strength_range] [-unique] [-vcdstim] <object_name> ...
Arguments
• -compress
(optional) Produces a compressed VCD file. ModelSim uses the gzip compression
algorithm. It is not necessary to specify -compress if you specify a .gz extension with the
-file <filename> argument
• -direction
(optional) Includes driver direction data in the VCD file.
• -file <filename>
(optional) Creates a VCD file. Defaults to the current working directory and the filename
dumpports.vcd. Multiple filenames can be opened during a single simulation.
<filename> — Specifies a filename. When specified with a .gz extension, the file is
compressed.
• -force_direction
(optional) Causes vcd dumpports to use the specified port direction (instead of driver
location) to determine whether the value being dumped is input or output. This argument
overrides the default use of the location of drivers on the net to determine port direction (this
is because Verilog port direction is not enforced by the language or by ModelSim).
• -in
(optional) Includes ports of mode IN.
• -out
(optional) Includes ports of mode OUT.
• -inout
(optional) Includes ports of mode INOUT.

ModelSim Reference Manual, v10.1c 257

Commands
vcd dumpports

• -no_strength_range
(optional) Ignores strength ranges when resolving driver values. This argument is an
extension to the IEEE 1364 specification. Refer to Resolving Values for additional
information.
• -unique
(optional) Generates unique VCD variable names for ports even if those ports are connected
to the same collapsed net.
• -vcdstim
(optional) Ensures that port name order in the VCD file matches the declaration order in the
instance module or entity declaration. Refer to Port Order Issues for further information.
• <object_name> ...
(required) Specifies one or more Verilog, VHDL, or SystemC objects to add to the VCD
file. You can specify multiple objects by separating names with spaces. Wildcards are
accepted. Must be specified as the final argument to the vcd dumpports command.
Examples
• Create a VCD file named counter.vcd of all IN ports in the region /test_design/dut/.
vcd dumpports -in -file counter.vcd /test_design/dut/*

• These two commands resimulate a design from a VCD file. Refer to Simulating with
Input Values from a VCD File for further details.
vcd dumpports -file addern.vcd /testbench/uut/*
vsim -vcdstim addern.vcd addern -gn=8 -do "add wave /*; run 1000"

• This series of commands creates VCD files for the instances proc and cache and then re-
simulates the design using the VCD files in place of the instance source files. Refer to
Replacing Instances with Output Values from a VCD File for more information.
vcd dumpports -vcdstim -file proc.vcd /top/p/*
vcd dumpports -vcdstim -file cache.vcd /top/c/*
run 1000

vsim top -vcdstim /top/p=proc.vcd -vcdstim /top/c=cache.vcd

258 ModelSim Reference Manual, v10.1c

Commands
vcd dumpports

Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpportsall • vcd off
• vcd dumpportsflush • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

ModelSim Reference Manual, v10.1c 259

Commands
vcd dumpportsall

vcd dumpportsall
This command creates a checkpoint in the VCD file which shows the value of all selected ports
at that time in the simulation, regardless of whether the port values have changed since the last
timestep.
Related Verilog task: $dumpportsall
Syntax
vcd dumpportsall [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on all
open VCD files.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsflush • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

260 ModelSim Reference Manual, v10.1c

Commands
vcd dumpportsflush

vcd dumpportsflush
This command flushes the contents of the VCD file buffer to the specified VCD file.
Related Verilog task: $dumpportsflush
Syntax
vcd dumpportsflush [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on all
open VCD files.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportslimit • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

ModelSim Reference Manual, v10.1c 261

Commands
vcd dumpportslimit

vcd dumpportslimit
This command specifies the maximum size of the VCD file (by default, limited to available disk
space). When the size of the file exceeds the limit, a comment is appended to the file and VCD
dumping is disabled.
Related Verilog task: $dumpportslimit
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
vcd dumpportslimit <dumplimit> [<filename>]
Arguments
• <dumplimit>
(required) Specifies the maximum VCD file size in bytes. Must be specified as the first
argument to the vcd dumpportslimit command.
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on all
open VCD files.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportsflush • vcd2wlf
• vcd dumpportsoff • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

262 ModelSim Reference Manual, v10.1c

Commands
vcd dumpportsoff

vcd dumpportsoff
This command turns off VCD dumping and records all dumped port values as x.
Related Verilog task: $dumpportsoff
Syntax
vcd dumpportsoff [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on all
open VCD files.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportsflush • vcd2wlf
• vcd dumpportslimit • DumpportsCollapse
• vcd dumpportson • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

ModelSim Reference Manual, v10.1c 263

Commands
vcd dumpportson

vcd dumpportson
This command turns on VCD dumping and records the current values of all selected ports. This
command is typically used to resume dumping after invoking vcd dumpportsoff.
Related Verilog task: $dumpportson
Syntax
vcd dumpportson [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on all
open VCD files.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportsflush • vcd2wlf
• vcd dumpportslimit • DumpportsCollapse
• vcd dumpportsoff • Value Change Dump (VCD) Files
• vcd file • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

264 ModelSim Reference Manual, v10.1c

Commands
vcd file

vcd file
This command specifies the filename and state mapping for the VCD file created by a vcd add
command. The vcd file command is optional. If used, it must be issued before any vcd add
commands.
Related Verilog task: $dumpfile
Syntax
vcd file [-dumpports] [-direction] [<filename>] [-map <mapping pairs>] [-no_strength_range]
[-nomap] [-unique]
Arguments
• -dumpports
(optional) Capture detailed port driver data for Verilog ports and VHDL std_logic ports.
This option works only on ports, and any subsequent vcd add command will accept only
qualifying ports (silently ignoring all other specified objects).
• -direction
(optional) Includes driver direction data in the VCD file.
• <filename>
(optional) Specifies the name of the VCD file that is created where the default is dump.vcd.
• -map <mapping pairs>
(optional) Overrides the default mappings. Affects only VHDL signals of type std_logic.
<mapping pairs> — Specified as a list of character pairs. The first character in a pair
must be one of the std_logic characters UX01ZWLH- and the second character is the
character you wish to be recorded in the VCD file. The Tcl convention for command
strings that include spaces is to enclose them in quotation marks (" "). For example, to
map L and H to z:
vcd file -map "L z H z"

• -no_strength_range
(optional) Ignores strength ranges when resolving driver values. This argument is an
extension to the IEEE 1364 specification. Refer to Resolving Values for additional
information.
• -nomap
(optional) Affects only VHDL signals of type std_logic. It specifies that the values recorded
in the VCD file shall use the std_logic enumeration characters of UX01ZWLH-. This option
results in a non-standard VCD file because VCD values are limited to the four state
character set of x01z. By default, the std_logic characters are mapped as follows.

ModelSim Reference Manual, v10.1c 265

Commands
vcd file

VHDL VCD VHDL VCD

U x W x
X x L 0
0 0 H 1
1 1 - x
Z z
• -unique
(optional) Generates unique VCD variable names for ports even if those ports are connected
to the same collapsed net.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportsflush • vcd2wlf
• vcd dumpportslimit • DumpportsCollapse
• vcd dumpportsoff • Value Change Dump (VCD) Files
• vcd dumpportson • Verilog tasks are documented in the
Language Reference Manual IEEE 1364
standard.

266 ModelSim Reference Manual, v10.1c

Commands
vcd files

vcd files
This command specifies filenames and state mapping for VCD files created by the vcd add
command. The vcd files command is optional. If used, it must be issued before any vcd add
commands.
Related Verilog task: $fdumpfile
Syntax
vcd files [-compress] [-direction] <filename> [-map <mapping pairs>] [-no_strength_range]
[-nomap] [-unique]
Arguments
• -compress
(optional) Produces a compressed VCD file. ModelSim uses the gzip compression
algorithm. If you specify a .gz extension on the -file <filename> argument, ModelSim
compresses the file even if you don’t use the -compress argument.
• -direction
(optional) Includes driver direction data in the VCD file.
• <filename>
(required) Specifies the name of a VCD file to create. Multiple files can be opened during a
single simulation; however, you can create only one file at a time. If you want to create
multiple files, invoke vcd files multiple times.
• -map <mapping pairs>
(optional) Overrides the default mappings. Affects only VHDL signals of type std_logic.
<mapping pairs> — Specified as a list of character pairs. The first character in a pair
must be one of the std_logic characters UX01ZWLH- and the second character is the
character you wish to be recorded in the VCD file. The Tcl convention for command
strings that include spaces is to enclose them in quotation marks (" "). For example, to
map L and H to z:
vcd file -map "L z H z"

• -no_strength_range
(optional) Ignores strength ranges when resolving driver values. This argument is an
extension to the IEEE 1364 specification. Refer to “Resolving Values” for additional
information.
• -nomap
(optional) Affects only VHDL signals of type std_logic. It specifies that the values recorded
in the VCD file shall use the std_logic enumeration characters of UX01ZWLH-. This option

ModelSim Reference Manual, v10.1c 267

Commands
vcd files

results in a non-standard VCD file because VCD values are limited to the four state
character set of x01z. By default, the std_logic characters are mapped as follows.
VHDL VCD VHDL VCD
U x W x
X x L 0
0 0 H 1
1 1 - x
Z z
• -unique
(optional) Generates unique VCD variable names for ports even if those ports are connected
to the same collapsed net.
Examples
The following example shows how to "mask" outputs from a VCD file until a certain time after
the start of the simulation. The example uses two vcd files commands and the vcd on and
vcd off commands to accomplish this task.
vcd files in_inout.vcd
vcd files output.vcd
vcd add -in -inout -file in_inout.vcd /*
vcd add -out -file output.vcd /*
vcd off output.vcd
run 1us
vcd on output.vcd
run -all

Related Topics
• vcd add • vcd flush
• vcd checkpoint • vcd limit
• vcd comment • vcd off
• vcd dumpports • vcd on
• vcd dumpportsall • vcd2wlf
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

268 ModelSim Reference Manual, v10.1c

Commands
vcd flush

vcd flush
This command flushes the contents of the VCD file buffer to the specified VCD file. This
command is useful if you want to create a complete VCD file without ending your current
simulation.
Related Verilog tasks: $dumpflush, $fdumpflush
Syntax
vcd flush [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted, the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd limit
• vcd comment • vcd off
• vcd dumpports • vcd on
• vcd dumpportsall • vcd2wlf
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

ModelSim Reference Manual, v10.1c 269

Commands
vcd limit

vcd limit
This command specifies the maximum size of a VCD file (by default, limited to available disk
space).
When the size of the file exceeds the limit, a comment is appended to the file and VCD dumping
is disabled.
Related Verilog tasks: $dumplimit, $fdumplimit
Arguments to this command are order dependent. Please read the argument descriptions for
more information.
Syntax
vcd limit <filesize> [<filename>]
Arguments
• <filesize>
(Required) Specifies the maximum VCD file size, in bytes. The numerical value of
<filesize> can only be a whole number. Must be specified as the first argument to the vcd
limit command.
You can specify a unit of Kb, Mb, or Gb with the numerical value (units are case
insensitive). Do not insert a space between the numerical value and the unit (for example,
400Mb, not 400 Mb).
• <filename>
(Optional) Specifies the name of the VCD file. If omitted, the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Example
• Specify a maximum VCD file size of 6 gigabytes and a VCD file named
my_vcd_file.vcd.
vcd limit 6gb my_vcd_file.vcd

Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd off
• vcd dumpports • vcd on
• vcd dumpportsall • vcd2wlf
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

270 ModelSim Reference Manual, v10.1c

Commands
vcd off

vcd off
This command turns off VCD dumping to the specified file and records all VCD variable values
as x.
Related Verilog tasks: $dumpoff, $fdumpoff
Syntax
vcd off [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted, the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd on
• vcd dumpportsall • vcd2wlf
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

ModelSim Reference Manual, v10.1c 271

Commands
vcd on

vcd on
This command turns on VCD dumping to the specified file and records the current values of all
VCD variables.
By default, vcd on is automatically performed at the end of the simulation time that the vcd add
command performed.
Related Verilog tasks: $dumpon, $fdumpon
Syntax
vcd on [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the VCD file. If omitted the command is executed on the
file designated by the vcd file command or dump.vcd if vcd file was not invoked.
Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd2wlf
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

272 ModelSim Reference Manual, v10.1c

Commands
vcd2wlf

vcd2wlf
This command is a utility that translates a VCD (Value Change Dump) file into a WLF file that
you can display in ModelSim using the vsim -view argument. This command only works on
VCD files containing positive time values.
Description
The vcd2wlf command functions as simple one-pass converter. If you are defining a bus in a
VCD file, you must specify all bus bits before the next $scope or $upscope statement appears in
the file. The best way to ensure that bits get converted together as a bus is to declare them on
consecutive lines.
For example:
Line 21 : $var wire 1 $ in [2] $end
Line 22 : $var wire 1 $u in [1] $end
Line 23 : $var wire 1 # in [0] $end

Arguments to this command are order dependent. Please read the argument descriptions for
more information.

Syntax
vcd2wlf [-splitio] [-splitio_in_ext <extension>] [-splitio_out_ext <extension>] [-nocase]
{<vcd filename> | – } <wlf filename>
Arguments
• -splitio
(optional) Specifies that extended VCD port values are to be split into their corresponding
input and output components by creating two signals instead of just one in the resulting .wlf
file. By default the new input-component signal keeps the same name as the original port
name while the output-component name is the original name with "__o" appended to it.
• -splitio_in_ext <extension>
(optional) Adds an extension to input-component signal names created by using -splitio.
<extension> — Specifies a string.
• -splitio_out_ext <extension>
(optional) Adds an extension to output-component signal names created by using -splitio.
<extension> — Specifies a string.
• -nocase
(optional) Converts all alphabetic identifiers to lowercase.

ModelSim Reference Manual, v10.1c 273

Commands
vcd2wlf

• {<vcd filename> | – }
(required) Specifies the name of the VCD file, or standard input (-), you want to translate
into a WLF file. Must be specified immediately preceding the <wlf filename> argument to
the vcd2wlf command.
• <wlf filename>
(required) Specifies the name of the output WLF file. Must be specified as the final
argument to the vcd2wlf command.
Example
• Concatenate my.vcd file and pipe standard input to vcd2wlf and save output to my.wlf
file.
cat my.vcd | vcd2wlf - my.wlf

• Redirect input from the file my.vcd file to vcd2wlf and save the output to my.wlf file.
vcd2wlf - my.wlf <my.vcd

Related Topics
• vcd add • vcd files
• vcd checkpoint • vcd flush
• vcd comment • vcd limit
• vcd dumpports • vcd off
• vcd dumpportsall • vcd on
• vcd dumpportsflush • DumpportsCollapse
• vcd dumpportslimit • Value Change Dump (VCD) Files
• vcd dumpportsoff • Verilog tasks are documented in the
• vcd dumpportson Language Reference Manual IEEE 1364
• vcd file standard.

274 ModelSim Reference Manual, v10.1c

Commands
vcom

vcom
The vcom command compiles VHDL source code into a specified working library (or to the
Commands

work library by default).

You can invoke vcom either from within ModelSim or from the command prompt of your
operating system. You can invoke this command during simulation.
Compiled libraries are dependent on the major version of ModelSim. When moving between
major versions, you must refresh compiled libraries using the -refresh argument to vcom. This
is not required for minor versions (letter releases).
All arguments to the vcom command are case-sensitive. For example, -WORK and -work are
not equivalent.
This command provides additional information with the -help switch.

Syntax
vcom [options] <filename> [<filename> ...]
[options]:
[-87 | -93 | -2002 | -2008]
[-addpragmaprefix <prefix>]
[-allowProtectedBeforeBody] [-amsstd | -noamsstd]
[-bindAtCompile] [-bindAtLoad]
[-check_synthesis]
[-debugVA] [-deferSubpgmCheck | -noDeferSubpgmCheck]
[-error <msg_number>[,<msg_number>,…]] [-explicit]
[-f <filename>] [-fatal <msg_number>[,<msg_number>,…]]
[-force_refresh <design_unit>] [-fsmimplicittrans | -nofsmimplicittrans]
[-fsmresettrans | -nofsmresettrans ] [-fsmsingle | -nofsmsingle ]
[-fsmverbose [b | t | w]]
[-gen_xml <design_unit> <filename>]
[-ignoredefaultbinding] [-ignorepragmaprefix <prefix>] [ignoreStandardRealVector]
[-ignorevitalerrors] [-initoutcompositeparam | -noinitoutcompositeparam]
[-just abcep]
[-l <filename>] [-line <number>] [-lint] [-lower] [-lrmVHDLConfigVis]
[-mixedsvvh [b | l | r ][i]] [-modelsimini <ini_filepath>]
[-no1164] [-noaccel <package_name>] [-nocasestaticerror] [-nocheck] [-nodbgsym]
[]-nofprangecheck [-noFunctionInline] [-noindexcheck] [-nologo] [-nonstddriverinit]
[-noothersstaticerror]
[-note <msg_number> [,<msg_number>, …]] [-novital] [-novitalcheck]
[-nowarn <category_number>]
[-oldconfigvis]

ModelSim Reference Manual, v10.1c 275

Commands
vcom

[-pedanticerrors] [-performdefaultbinding] [-preserve]

[-quiet]
[-rangecheck | -norangecheck] [-refresh]
[-s] [-separateConfigLibrary] [-skip abcep] [-source]
[-suppress <msg_number>[,<msg_number>,…]]
[-time]
[-version] [-vmake]
[-warning <msg_number>[,<msg_number>,…]] [-work <library_name>]
Arguments
• -87 | -93 | -2002 | -2008
(optional) Specifies which LRM-specific compiler to use. You can also control this
behavior with the VHDL93 variable in the modelsim.ini file. Refer to “Differences Between
Versions of VHDL” for more information.
-87 — Enables support for VHDL 1076-1987.
-93 — Enables support for VHDL 1076-1993.
-2002 — Enables support for VHDL 1076-2002. (default)
-2008 — Enables support for VHDL 1076-2008.
• -addpragmaprefix <prefix>
(optional) Enables recognition of synthesis and coverage pragmas with a user specified
prefix. If this argument is not specified, pragmas are treated as comments. All regular
synthesis and coverage pragmas are honored.
<prefix> — Specifies a user defined string where the default is no sting, indicated by
quotation marks.
You may also set this with the AddPragmaPrefix variable in the vcom section of the
modelsim.ini file.
• -allowProtectedBeforeBody
(optional) Allows a variable of a protected type to be created prior to declaring the body.
• -amsstd | -noamsstd
(optional) Specifies whether vcom adds the declaration of REAL_VECTOR to the
STANDARD package. This is useful for designers using VHDL-AMS to test digital parts of
their model.
-amsstd — REAL_VECTOR is included in STANDARD.
-noamsstd — REAL_VECTOR is not included in STANDARD (default).
You can also control this with the AmsStandard variable or the MGC_AMS_HOME
environment variable.

276 ModelSim Reference Manual, v10.1c

Commands
vcom

• -bindAtCompile
(optional) Forces ModelSim to perform default binding at compile time rather than at load
time. Refer to “Default Binding” for more information. You can change the permanent
default by editing the BindAtCompile variable in the modelsim.ini.
• -bindAtLoad
(optional) Forces ModelSim to perform default binding at load time rather than at compile
time. (Default)
• -check_synthesis
(optional) Turns on limited synthesis rule compliance checking. Specifically, it checks to
see that signals read by a process are in the sensitivity list. The checks understand only
combinational logic, not clocked logic. Edit the CheckSynthesis variable in the modelsim.ini
file to set a permanent default.
• -debugVA
(optional) Prints a confirmation if a VITAL cell was optimized, or an explanation of why it
was not, during VITAL level-1 acceleration.
• -deferSubpgmCheck
(optional) Forces the compiler to report array indexing and length errors as warnings
(instead of as errors) when encountered within subprograms. Subprograms with indexing
and length errors that are invoked during simulation cause the simulator to report errors,
which can potentially slow down simulation because of additional checking.
• -error <msg_number>[,<msg_number>,…]
Optional) Changes the severity level of the specified message(s) to "error." Edit the error
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• -explicit
(optional) Directs the compiler to resolve ambiguous function overloading by favoring the
explicit function definition over the implicit function definition. Strictly speaking, this
behavior does not match the VHDL standard. However, the majority of EDA tools choose
explicit operators over implicit operators. Using this switch makes ModelSim compatible
with common industry practice.
• -f <filename>
(optional) Specifies a file with more command-line arguments. Allows complex argument
strings to be reused without retyping. Allows gzipped input files. Nesting of -f options is
allowed.
<filename> —
Refer to the section "Argument Files" for more information.

ModelSim Reference Manual, v10.1c 277

Commands
vcom

• -fatal <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "fatal." Edit the fatal
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• -force_refresh <design_unit>
(optional) Forces the refresh of all specified design units. By default, the work library is
updated; use -work <library_name>, in conjunction with -force_refresh, to update a
different library (for example, vcom -work <your_lib_name> -force_refresh).
<design_unit> —
When the compiler refreshes a design unit, it checks each dependency to ensure its source
has not been changed and recompiled. Sometimes the dependency checking algorithm
changes from release to release. This can lead to false errors during the integrity checks
performed by the -refresh argument. An example of such a message follows:
** Error: (vsim-13) Recompile /u/test/dware/dware_61e_beta.dwpackages
because /home/users/questasim/linux/../synopsys.attributes has changed.

The -force_refresh argument forces the refresh of the design unit, overriding any
dependency checking errors encountered by the -refresh argument.
A more conservative approach to working around -refresh dependency checks is to
recompile the source code, if it is available.
• -fsmimplicittrans | -nofsmimplicittrans
(optional) Toggles recognition of implied same state transitions, which is off by default
(-nofsmimplicittrans).
• -fsmresettrans | -nofsmresettrans
(optional) Toggles recognition of sychronous or asynchronous reset transitions, and is on by
default (-fsmresettrans). This includes/excludes reset transitions in coverage results.
• -fsmsingle | -nofsmsingle
(optional) Toggles the recognition of VHDL FSMs where the current state variable of type
std_logic, bit, boolean, or single-bit std_logic_vector/bit_vector and Verilog single-bit
FSMs.
• -fsmverbose [b | t | w]
(optional) Provides information about FSMs detected, including state reachability analysis.
b — displays only basic information.
t — displays a transition table in addition to the basic information.
w — displays any warning messages in addition to the basic information.
When you do not specify an argument, this switch reports all information similar to:

278 ModelSim Reference Manual, v10.1c

Commands
vcom

# ** Note: (vcom-1947) FSM RECOGNITION INFO

# Fsm detected in : ../fpu/rtl/vhdl/serial_mul.vhd
# Current State Variable : s_state :
../fpu/rtl/vhdl/serial_mul.vhd(76)
# Clock : clk_i
# Reset States are: { waiting , busy }
# State Set is : { busy , waiting }
# Transition table is
# -------------------------------------------
# busy => waiting Line : (114 => 114)
# busy => busy Line : (111 => 111)
# waiting => waiting Line : (120 => 120) (114 => 114)
# waiting => busy Line : (111 => 111)
# -------------------------------------------

When you do not specify this switch, you will receive a message similar to:
# ** Note: (vcom-143) Detected '1' FSM/s in design unit
'serial_mul.rtl'.

• -gen_xml <design_unit> <filename>

(optional) Produces an XML-tagged file containing the interface definition of the specified
entity.
<design_unit> — The name of an entity or design unit in the Work library. Wildcards
and multiple design unit names are not allowed.
<filename> — A user-specified name for the file.
For example:
This option requires a two-step process where you must:
1) compile <filename> into a library with vcom (without -gen_xml) then
2) execute vcom with the -gen_xml switch.
vlib work
vcom counter.vhd
vcom -gen_xml counter counter.xml

• -ignoredefaultbinding
(optional) Instructs the compiler not to generate a default binding during compilation. You
must explicitly bind all components in the design to use this switch.
• -ignorepragmaprefix <prefix>
(optional) Directs vcom to ignore synthesis and coverage pragmas with the specified
prefixname. All affected pragmas will be treated as regular comments. Edit the
IgnorePragmaPrefix modelsim.ini variable to set a permanent default.
<prefix> — Specifies a user defined string.
• ignoreStandardRealVector
(optional) Instructs ModelSim to ignore the REAL_VECTOR declaration in package
STANDARD when compiling with vcom -2008. Edit the ignoreStandardRealVector
modelsim.ini variable to set a permanent default. For more information refer to the
REAL_VECTOR section in Help > Technotes > vhdl2008migration.

ModelSim Reference Manual, v10.1c 279

Commands
vcom

• -ignorevitalerrors
(optional) Directs the compiler to ignore VITAL compliance errors. The compiler still
reports that VITAL errors exist, but it will not stop the compilation. You should exercise
caution in using this switch; as part of accelerating VITAL packages, we assume that
compliance checking has passed.
• -initoutcompositeparam
(optional) Causes initialization of subprogram parameters for array and record types when
the subprogram is executed in designs compiled with LRM 1076-2002 and earlier. This
argument forces the output parameters to their default initial (“left”) values when entering a
subprogram. By default, -initoutcompositeparam is enabled for designs compiled with
vcom -2008 and later. You can also enable this by setting the InitiOutCompositeParam
variable to 1 in the modelsim.ini file.
• -noinitoutcompositeparam
(optional) Disables initialization of subprogram parameters for array and record types when
the subprogram is executed in designs compiled with LRM 1076-2002 and earlier. By
default, designes compiled with LRM 1076-2008 and later do not initialize subprogram
parameters for array and record types when the subprogram is executed. You can also
disable initialization of subprogram parameters for array and record types by setting the
InitiOutCompositeParam variable to 2 in the modelsim.ini file.
• -just abcep
(optional) Directs the compiler to include only the following:
a — architectures
b — bodies
c — configurations
e — entities
p — packages
Any combination in any order can be used, but you must specify at least one choice if you
use this switch.
• -l <filename>
(optional) Generates a log file of the compile.
• -line <number>
(optional) Starts the compiler on the specified line in the VHDL source file. By default, the
compiler starts at the beginning of the file.
<number> —
• -lint
(optional) Performs additional static checks on case statement rules and enables warning
messages for the following situations:

280 ModelSim Reference Manual, v10.1c

Commands
vcom

o The result of the built-in concatenation operator ("&") is the actual for a subprogram
formal parameter of an unconstrained array type.
o If you specify the -BindAtCompile switch with vcom, the entity to which a
component instantiation is bound has a port that is not on the component, and for
which there is no error otherwise.
o A direct recursive subprogram call.
o In cases involving class SIGNAL formal parameters, as described in the IEEE
Standard VHDL Language Reference Manual entitled "Signal parameters". This
check only applies to designs compiled using -87. If you compile using -93, it would
be flagged as a warning or error, even without the -lint argument. Can also be
enabled using the Show_Lint variable in the modelsim.ini file.
• -lower
(optional) Forces vcom to convert uppercase letters in object identifiers to lowercase. You
can also enable this by setting the PreserveCase variable to 0 in the modelsim.ini file.
• -lrmVHDLConfigVis
(optional, default) Forces vcom to use visibility rules that comply with the Language
Reference Manual when processing VHDL configurations. Refer to vcom -oldconfigvis or
the oldVHDLConfigurationVisibility variable in the modelsim.ini file for more information.
• -mixedsvvh [b | l | r ][i]
(optional) Facilitates using VHDL packages at the SystemVerilog-VHDL boundary of a
mixed-language design. When you compile a VHDL package with -mixedsvvh, the
package can be included in a SystemVerilog design as if it were defined in SystemVerilog
itself.
Executing -mixedsvvh without arguments compiles VHDL vectors in the following ways:
• VHDL bit_vectors are treated as SystemVerilog bit vectors.
• VHDL std_logic_vectors, std_ulogic_vectors, and vl_logic_vectors are treated as
SystemVerilog logic vectors.
b — treats all scalars and vectors in the package as SystemVerilog bit type
l — treats all scalars and vectors in the package as SystemVerilog logic type
r — treats all scalars and vectors in the package as SystemVerilog reg type
i — ignores the range specified with VHDL integer types. Can be specified together
with b, l, or r, spaces are not allowed between arguments.
• -modelsimini <ini_filepath>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable.
<ini_filepath> — Specifies either an absolute or relative path to the initialization file.
On Windows systems the path separator should be a forward slash (/).

ModelSim Reference Manual, v10.1c 281

Commands
vcom

• -no1164
(optional) Causes the source files to be compiled without taking advantage of the built-in
version of the IEEE std_logic_1164 package. This will typically result in longer simulation
times for VHDL programs that use variables and signals of type std_logic.
• -noaccel <package_name>
(optional) Turns off acceleration of the specified package in the source code using that
package.
<package_name> — A VHDL package name.
• -nocasestaticerror
(optional) Suppresses case statement static warnings. VHDL standards require that case
statement alternative choices be static at compile time. However, some expressions which
are globally static are allowed. This switch prevents the compiler from warning on such
expressions. If the -pedanticerrors switch is specified, this switch is ignored.
• -nocheck
(optional) Disables index and range checks. You can disable these individually using the
-noindexcheck and -norangecheck arguments, respectively.
• -nodbgsym
(optional) Disables the generation of the symbols debugging database in the compiled
library.
The symbols debugging database is the .dbs file in the compiled library that provides
information to the GUI allowing you to view detailed information about design objects at
the source level. Two major GUI features that use this database include source window
annotation and textual dataflow.
You should only specify this switch if you know that anyone using the library will not
require this information for design analysis purposes.
• -noDeferSubpgmCheck
(optional) Causes range and length violations detected within subprograms to be reported as
errors (instead of as warnings). As an alternative to using this argument, you can set the
NoDeferSubpgmCheck variable in the modelsim.ini file to a value of 1.
• -nofprangecheck
(optional) Disables range checks on floating type values only.
• -noFunctionInline
(optional) Turns off VHDL subprogram inlining for design units using a local copy of a
VHDL package. This may be needed in case the local package has the same name as an MTI
supplied package.

282 ModelSim Reference Manual, v10.1c

Commands
vcom

• -noindexcheck
(optional) Disables checking on indexing expressions to determine whether indexes are
within declared array bounds.
• -nologo
(optional) Disables display of the startup banner.
• -nonstddriverinit
(optional) Forces ModelSim to match pre-5.7c behavior in initializing drivers in a particular
case. Prior to 5.7c, VHDL ports of mode out or inout could have incorrectly initialized
drivers if the port did not have an explicit initialization value and the actual signal connected
to the port had explicit initial values. Depending on a number of factors, ModelSim could
incorrectly use the actual signal's initial value when initializing lower level drivers. Note
that the argument does not cause all lower-level drivers to use the actual signal's initial
value. It does this only in the specific cases where older versions used the actual signal's
initial value.
• -noothersstaticerror
(optional) Disables warnings that result from array aggregates with multiple choices having
"others" clauses that are not locally static. If -pedanticerrors is specified, this switch is
ignored.
• -norangecheck
(optional) Disables run time range checking. In some designs, this results in a 2X speed
increase. Range checking is enabled by default or, once disabled, can be enabled using
-rangecheck. If you run a simulation with range checking disabled, any scalar values that
are out of range are indicated by showing the value in the following format: ?(N) where N is
the current value. Refer to “Range and Index Checking” for additional information. I
• -note <msg_number> [,<msg_number>, …]
(optional) Changes the severity level of the specified message(s) to "note. Edit the note
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• -novital
(optional) Causes vcom to use VHDL code for VITAL procedures rather than the
accelerated and optimized timing and primitive packages built into the simulator kernel.
Allows breakpoints to be set in the VITAL behavior process and permits single stepping
through the VITAL procedures to debug your model. Also all of the VITAL data can be
viewed in the Locals or Objects windows.
• -novitalcheck
(optional) Disables Vital level 1 and Vital level 0 checks defined in section 4 of the Vital-95
Spec (IEEE Std 1076.4-1995).

ModelSim Reference Manual, v10.1c 283

Commands
vcom

• -nowarn <category_number>
(optional) Selectively disables a category of warning messages. Warnings may be disabled
for all compiles via the Main window Compile > Compile Options menu command or the
modelsim.ini file (Refer to modelsim.ini Variables).
<category_number> — Specifies one or more numbers corresponding to the categories
in Table 2-5 Multiple message categories are specified as a comma separated list.
Table 2-5. Warning Message Categories for vcom -nowarn
Category Description
number
1 unbound component
2 process without a wait statement
3 null range
4 no space in time literal
5 multiple drivers on unresolved signal
6 VITAL compliance checks (“VitalChecks” also works)
7 VITAL optimization messages
8 lint checks
9 signal value dependency at elaboration
10 VHDL-1993 constructs in VHDL-1987 code
13 constructs that coverage can't handle
14 locally static error deferred until simulation run
• -oldconfigvis
(optional) Forces vcom to process visibility of VHDL component configurations consistent
with prior releases. Default behavior is to comply with Language Reference Manual
visibility rules. Refer to vcom -lrmVHDLConfigVis or the modelsim.ini variable
OldVHDLConfigurationVisibility for more information.
• -pedanticerrors
(optional) Forces display of an error message (rather than a warning) on a variety of
conditions. Refer to “Enforcing Strict 1076 Compliance” for a complete list of these
conditions. This argument overrides -nocasestaticerror and -noothersstaticerror (see
above).
• -performdefaultbinding
(optional) Enables default binding when it has been disabled via the
RequireConfigForAllDefaultBinding option in the modelsim.ini file.

284 ModelSim Reference Manual, v10.1c

Commands
vcom

• -preserve
(optional) Forces vcom to preserve the case of letters in object identifiers. Can also be
enabled by setting the PreserveCase variable to 1 in the modelsim.ini file.
• -quiet
(optional) Disables ‘Loading’ messages.
• -rangecheck
(default) Enables run time range checking. Range checking can be disabled using the
-norangecheck argument. Refer to “Range and Index Checking” for additional information.
• -refresh
(optional) Regenerates a library image. By default, the work library is updated. To update a
different library, use -work <library_name> with -refresh (for example, vcom -work
<your_lib_name> -refresh). If a dependency checking error occurs which prevents the
refresh, use the vcom -force_refresh argument. Refer to the vcom Examples for more
information. You may use a specific design name with -refresh to regenerate a library
image for that design, but you may not use a file name.
• -s
(optional) Instructs the compiler not to load the standard package. This argument should
only be used if you are compiling the standard package itself.
• -separateConfigLibrary
Allows the declaration of a VHDL configuration to occur in a different library than the
entity being configured. Strict conformance to the VHDL standard (LRM) requires that they
be in the same library. This argument must be used if optimization is disabled (-novopt).
• -skip abcep
(optional) Directs the compiler to skip all:
a — architectures
b — bodies
c — configurations
e — entities
p — packages
Any combination in any order can be used, but one choice is required if you use this switch.
• -source
(optional) Displays the associated line of source code before each error message that is
generated during compilation. By default, only the error message is displayed.
• -suppress <msg_number>[,<msg_number>,…]
(optional) Prevents the specified message(s) from displaying. The <msg_number> is the
number preceding the message you wish to suppress. You cannot suppress Fatal or Internal

ModelSim Reference Manual, v10.1c 285

Commands
vcom

messages. Edit the suppress variable in the modelsim.ini file to set a permanent default.
Refer to “Changing Message Severity Level” for more information.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• -time
(optional) Reports the "wall clock time" vcom takes to compile the design. Note that if
many processes are running on the same system, wall clock time may differ greatly from the
actual "cpu time" spent on vcom.
• -version
(optional) Returns the version of the compiler as used by the licensing tools.
• -vmake
(optional) Generates a complete record of all command line data and files accessed during
the compile of a design. This data is then used by the vmake command to generate a
comprehensive makefile for recompiling the design library. By default, vcom stores
compile data needed for the -refresh switch and ignores compile data not needed for
-refresh. The -vmake switch forces inclusion of all file dependencies and command line
data accessed during a compile, whether they contribute data to the initial compile or not.
Executing this switch can increase compile time in addition to increasing the accuracy of the
compile. See the vmake command for more information.
• -warning <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "warning." Edit the
warning variable in the modelsim.ini file to set a permanent default. Refer to “Changing
Message Severity Level” for more information.
<msg_number> — A number identifying the message. Multiple message numbers are
specified as a comma separated list.
• -work <library_name>
(optional) Maps a library to the logical library work. By default, the compiled design units
are added to the work library. The specified pathname overrides the pathname specified for
work in the project file.
<library_name> — A logical name or pathname of a library.
• <filename>
(required) Specifies the name of a file containing the VHDL source to be compiled. One
filename is required; multiple filenames can be entered separated by spaces .Wildcards may
be used, for example, *.vhd.
If you don’t specify a filename, and you are using the GUI, a dialog box pops up allowing
you to select the options and enter a filename.
Examples
• Compile the VHDL source code contained in the file example.vhd.

286 ModelSim Reference Manual, v10.1c

Commands
vcom

vcom example.vhd

• ModelSim supports designs that use elements conforming to the 1987, 1993, and 2002
standards. Compile the design units separately using the appropriate switches.
vcom -87 o_units1.vhd o_units2.vhd
vcom -93 n_unit91.vhd n_unit92.vhd

• When compiling source that uses the numeric_std package, this command turns off
acceleration of the numeric_std package, located in the ieee library.
vcom -noaccel numeric_std example.vhd

• Although it is not obvious, the = operator is overloaded in the std_logic_1164 package.

All enumeration data types in VHDL get an “implicit” definition for the = operator. So
while there is no explicit = operator, there is an implicit one. This implicit declaration
can be hidden by an explicit declaration of = in the same package (LRM Section 10.3).
However, if another version of the = operator is declared in a different package than that
containing the enumeration declaration, and both operators become visible through use
clauses, neither can be used without explicit naming.
vcom -explicit example.vhd

To eliminate that inconvenience, the VCOM command has the -explicit option that
allows the explicit = operator to hide the implicit one. Allowing the explicit declaration
to hide the implicit declaration is what most VHDL users expect.
ARITHMETIC."="(left, right)

• The -work option specifies mylib as the library to regenerate. -refresh rebuilds the
library image without using source code, allowing models delivered as compiled
libraries without source code to be rebuilt for a specific release of ModelSim (4.6 and
later only).
vcom -work mylib -refresh

ModelSim Reference Manual, v10.1c 287

Commands
vdel

vdel
This command deletes a design unit from a specified library.
This command provides additional information with the -help switch.

Syntax
vdel [-lib <library_path>] [-modelsimini <ini_filepath>] [-verbose]
{ -all | <primary> [<arch_name>]| -obj [object_info] | -dpiobj [object_info] }
Arguments
• -all
(optional) Deletes an entire library.
Caution
You cannot recover libraries cannot once deleted. You are not prompted for confirmation.

• -dpiobj [<object_info]
(optional) Delete auto-compiled DPI object files.
<object_info> — Specifies the type of object to remove, as reported by the output of the
vdir -obj command. This will take the form of either:
<compiler> — a string identifying the compiler, such as gcc-3.3.1.
<platform> — a string identifying the platform, such as linux.
<platform-compiler> — a string identifying a compiler/platform pair, such as
linux_gcc-3.2.3.
all — Specifies that all objects should be removed, as reported by the output of the
vdir -obj command.
• -lib <library_path>
(optional) Specifies location of the library that holds the design unit to be deleted. By
default, the design unit is deleted from the work library.
<library_path> — A logical name or pathname of the library.
• -modelsimini <ini_filepath>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable.
<ini_filepath> — Specifies either an absolute or relative path to the initialization file.
On Windows systems the path separator should be a forward slash (/).
• -obj {<object_info>}
(optional) removes directories containing DPI object files.
<object_info> — Specifies the type of directory to remove, as reported by the output of
the vdir -obj command. This will take the form of either:

288 ModelSim Reference Manual, v10.1c

Commands
vdel

<compiler> — a string identifying the compiler, such as gcc-3.3.1.

<platform> — a string identifying the platform, such as linux.
<platform-compiler> — a string identifying a compiler/platform pair, such as
linux_gcc-3.2.3.
all — Specifies that all directories should be removed, as reported by the output of
the vdir -obj command.
• <primary> [<arch_name>]
(required unless -all is used) Specifies the entity, package, configuration, or module to be
deleted.
<arch_name> — Specifies the name of an architecture to be deleted. If omitted, all of
the architectures for the specified entity are deleted. Invalid for a configuration or a
package.
• -verbose
(optional) Displays progress messages.
Examples
• Delete the work library.
vdel -all

• Delete the synopsys library.

vdel -lib synopsys -all

• Delete the entity named xor and all its architectures from the work library.
vdel xor

• Delete the architecture named behavior of the entity xor from the work library.
vdel xor behavior

• Delete the package named base from the work library.

vdel base

ModelSim Reference Manual, v10.1c 289

Commands
vdir

vdir
This command lists the contents of a design library and checks the compatibility of a vendor
library. If vdir cannot read a vendor-supplied library, the library may not be compatible with
ModelSim.
This command provides additional information with the -help switch.

Syntax
vdir [-l | [-prop <prop>]] [-r] [-all | [-lib <library_name>]] [<design_unit>]
[-modelsimini <ini_filepath>]
Arguments
• -all
(optional) Lists the contents of all libraries listed in the Library section of the active
modelsim.ini file. Refer to modelsim.ini Variables for more information.
• <design_unit>
(optional) Indicates the design unit to search for within the specified library. If the design
unit is a VHDL entity, its architectures are listed. By default all entities, configurations,
modules, packages, and optimized design units in the specified library are listed.
• -l
(optional) Prints the version of vcom/vlog with which each design unit was compiled, plus
any compilation options used. Also prints the object-code version number that indicates
which versions of vcom/vlog and ModelSim are compatible.
• -lib <library_name>
(optional) Specifies the logical name or the pathname of a library to be listed. By default,
the contents of the work library are listed.
<library_name> — A logical name or pathname of a library.
• -modelsimini <ini_filepath>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable.
<ini_filepath> — Specifies either an absolute or relative path to the initialization file.
On Windows systems the path separator should be a forward slash (/).
• -prop <prop>
(optional) Reports on a specified design unit property.

290 ModelSim Reference Manual, v10.1c

Commands
vdir

<prop> — Specifies a Design Unit Property, as listed in Table 2-6. If you do not specify
a value for <prop>, an error message is displayed.

Table 2-6. Design Unit Properties

Value of <prop> Description
archcfg configuration for arch
body needs a body
default default options
dir source directory
dpnd depends on
entcfg configuration for entity
fulloptions Full compile options
inline module inlined
lock lock/unlock status
lrm language standard
mtime source modified time
name short name
opcode opcode format
options compile options
pdu preoptimized design unit
root optimized Verilog design root
src source file
top top level model
ver version string
vlogv Verilog version
• -r
(optional) Prints architecture information for each entity in the output.
Examples
• List the architectures associated with the module named and2 that reside in the default
library work.
vdir -l and2

# Library vendor : Model Technology

# Maximum unnamed designs : 3

ModelSim Reference Manual, v10.1c 291

Commands
vdir

# MODULE and2
# Verilog version: <XO@d;_mSdz@12Fz9b]_Z3
# Version string: 3EdggZ>V3z51fE;>K[51?2
# Source directory: C:\examples\dataflow_verilog
# Source modified time: Tue Apr 28 22:48:56 2009
# HDL source file: gates.v
# Source file: gates.v
# Start location: gates.v:18
# Opcode format: 10.1a; VLOG SE Object version 51
# Optimized Verilog design root: 1
# VHDL language standard: 1
# Compile options: -L mtiAvm -L mtiOvm -L mtiUvm -L mtiUPF
# Debug Symbol file exists

292 ModelSim Reference Manual, v10.1c

Commands
vencrypt

vencrypt
This command encrypts Verilog and SystemVerilog code contained within encryption
envelopes. The code is not pre-processed before encryption, so macros and other `directives are
unchanged. This allows IP vendors to deliver encrypted IP with undefined macros and
`directives.
Upon execution of this command, the filename extension will be changed to .vp for Verilog
files (.v files) and .svp for SystemVerilog files (.sv files).
If the vencrypt utility processes the file (or files) and does not find any encryption directives it
reprocesses the file using the following default encryption:
`pragma protect data_method = "aes128-cbc"
`pragma protect key_keyowner = "MTI"
‘pragma protect key_keyname = "MGC-DVT-MTI"
‘pragma protect key_method = "rsa"
`pragma protect key_block encoding = (enctype = "base64")
`pragma protect begin

The vencrypt command must be followed by a compile command – such as vlog – for the
design to be compiled.
This command provides additional information with the -help switch.

Syntax
vencrypt <filename> [-d <dirname>] [-e <extension>] [-f <filename>] [-h <filename>]
[-l <filename>] [-o <filename>] [-p <prefix>] [-quiet]
• <filename>
(required) Specifies the name of the Verilog source code file to encrypt. One filename is
required. Multiple filenames can be entered separated by spaces. Wildcards can be used.
Default encryption pragmas will be used, as described above, if no encryption directives are
found during processing.
• -d <dirname>
(optional) Specifies where to save encrypted Verilog files. If no directory is specified,
current working directory will be used.
<dirname> — Specifies the directory to contain the encrypted Verilog or SystemVerilog
files. The original file extension (.v for Verilog and .sv for SystemVerilog) will be
preserved.
• -e <extension>
(optional) Specifies a filename extension.
<extension> — Any alpha-numeric string.
• -f <filename>
(optional) Specifies a file with more command line arguments. Allows complex arguments
to be reused without retyping. Nesting of -f options is allowed.

ModelSim Reference Manual, v10.1c 293

Commands
vencrypt

Refer to the section "Argument Files" for more information.

<filename> — Specifies the name of a file containing command line arguments.
• -h <filename>
(optional) Concatenates header information into all design files listed with <filename>.
Allows the user to pass a large number of files to the vencrypt utility that do not contain the
`pragma protect or `protect information about how to encrypt the file. Saves the user from
editing hundreds of files to add in the same `pragma protect to every file.
<filename> — Specifies an existing file.
• -l <filename>
(optional) Redirects log output to the file designated by <filename>.
<filename> — Specifies a file for saving output.
• -o <filename>
(optional) Combines all encrypted output into a single file.
<filename> — Specifies a file for saving output.
• -p <prefix>
(optional) Prepends file names with a prefix.
<prefix> — Any alpha-numeric string.
• -quiet
(optional) Disables encryption messages.
Example
• Insert header information into all design files listed.
vencrypt -h encrypt_head top.v cache.v gates.v memory.v

The encrypt_head file may look like the following:

`pragma protect data_method = "aes128-cbc"
`pragma protect author = "IP Provider"
`pragma protect key_keyowner = "MTI", key_method = "rsa"
`pragma protect key_keyname = "MGC-DVT-MTI"
`pragma protect begin

There is no `pragma protect end expression in the header file, just the header block that
starts the encryption. The `pragma protect end expression is implied by the end of the
file. For more detailed examples, see "Protecting Your Source Code" in the User’s
Manual.
Related Topics
• vhencrypt
• "Protecting Your Source Code" in the User’s Manual

294 ModelSim Reference Manual, v10.1c

Commands
verror

verror
This command prints a detailed description about a message number. It may also point to
additional documentation related to the error.
Syntax
verror [-fmt | -tag | -fmt -tag | -full] <msgNum> ...
verror [-fmt | -tag | -fmt -tag | -full] [-tool <tool>] -all
verror [-tool <tool>] -ranges
verror [-kind <tool>] {-pedanticerrors -permissive}
Arguments
• -fmt | -tag | -fmt -tag | -full
(optional) Specifies the type and amount of information to return.
-fmt — returns the format string used in the error message.
-tag — returns the tag associated with the error message.
-full — returns the format string, tag, and complete text associated with the error
message.
• -tool <tool> -all
(required when not specifying <msgNum> or -ranges) Returns information about all
messages associated with a specified tool, where <tool> can be one of the following:
common vcom vcom-vlog
vlog vsim vsim-vish
wlf vsim-sccom sccom
vsim-systemc ucdb vsim-vlog
pseudo_synth
• -kind <tool>
(optional) Specifies filtering for messages according to either or both of the following:
-pedanticerrors — display messages that are reported as errors due to adhering to a more
strict interpretation of the LRM.
-permissive — display messages reported as warnings that would be displayed as errors
if you use vsim -pedanticerrors.
where <tool> can be any of the values allowed for the -tool argument (above).
• <msgNum>
(required when not specifying -all or -ranges) Specifies the message number(s) you would
like more information about. You can find the message number in messages of the format:

ModelSim Reference Manual, v10.1c 295

Commands
verror

** <Level>: ([<Tool>-[<Group>-]]<MsgNum>) <FormattedMsg>

You can specify <msgNum> any number of times for one verror command in a space-
separated list.
Optionally, you can specify the toolname prior to the message number, similar to how it
appears in an error message. For example:
verror vsim-5003

• -ranges
(required when not specifying <msgNum> or -all) Prints the numeric ranges of error
message numbers, organized by tool.
Example
• If you receive the following message in the transcript:
** Error (vsim-3061) foo.v(22): Too many Verilog port connections.

and you would like more information about this message, you would type:
verror 3061

and receive the following output:

Message # 3061:
Too many Verilog ports were specified in a mixed VHDL/Verilog
instantiation. Verify that the correct VHDL/Verilog connection is
being made and that the number of ports matches.
[DOC: ModelSim User's Manual - Mixed VHDL and Verilog Designs
Chapter]

296 ModelSim Reference Manual, v10.1c

Commands
vgencomp

vgencomp
Once a Verilog module is compiled into a library, you can use this command to write its
equivalent VHDL component declaration to standard output.
Optional switches allow you to generate bit or vl_logic port types; std_logic port types are
generated by default.
This command provides additional information with the -help switch.

Syntax
vgencomp [-lib <library_name>] [-b] [-modelsimini <ini_filepath>] [-s] [-v] <module_name>
Arguments
• -lib <library_name>
(optional) Specifies the working library where the default is to use the work library.
<library_name> — Specifies the path and name of the working library.
• -b
(optional) Causes vgencomp to generate bit port types.
• -modelsimini <ini_filepath>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable.
<ini_filepath> — Specifies either an absolute or relative path to the initialization file.
On Windows systems the path separator should be a forward slash (/).
• -s
(optional) Used for the explicit declaration of default std_logic port types.
• -v
(optional) Causes vgencomp to generate vl_logic port types.
• <module_name>
(required) Specifies the name of the Verilog module to be accessed.
Examples
• This example uses a Verilog module that is compiled into the work library. The module
begins as Verilog source code:

ModelSim Reference Manual, v10.1c 297

Commands
vgencomp

module top(i1, o1, o2, io1);

parameter width = 8;
parameter delay = 4.5;
parameter filename = "file.in";

input i1;
output [7:0] o1;
output [4:7] o2;
inout [width-1:0] io1;
endmodule

After compiling, vgencomp is invoked on the compiled module:

vgencomp top

and writes the following to stdout:

component top
generic(
width : integer := 8;
delay : real := 4.500000;
filename : string := "file.in"
);
port(
i1 : in std_logic;
o1 : out std_logic_vector(7 downto 0);
o2 : out std_logic_vector(4 to 7);
io1 : inout std_logic_vector
);
end component;

298 ModelSim Reference Manual, v10.1c

Commands
vhencrypt

vhencrypt
This command encrypts VHDL code contained within encryption envelopes. The code is not
compiled before encryption, so dependent packages and design units do not have to exist before
encryption.
Upon execution of this command, the .vhd filename extension is changed to .vhdp and the .vhdl
filename extension is changed to .vhdlp.
If the vhencrypt utility does not find any encryption directives, no output file is produced.
The vhencrypt command must be followed by a compile command – such as vcom – for the
design to be compiled.
This command provides additional information with the -help switch.

Syntax
vhencrypt <filename> [-d <dirname>] [-e <extension>] [-f <filename>] [-h <filename>]
[-l <filename>] [-o <filename>] [-p <prefix>] [-quiet]
• <filename>
(required) Specifies the name of the VHDL source code file to encrypt. One filename is
required. Multiple filenames can be entered separated by spaces. Wildcards can be used.
• -d <dirname>
(optional) Specifies where to save encrypted VHDL files. If no directory is specified, the
current working directory will be used.
<dirname> — Specifies the directory to contain the encrypted VHDL files. The original
file extension (.vhd or .vhdl) will be preserved.
• -e <extension>
(optional) Specifies a filename extension to be applied to the encrypted file.
<extension> — Any alpha-numeric string.
• -f <filename>
(optional) Specifies a file with more command line arguments. Allows complex arguments
to be reused without retyping. Nesting of -f options is allowed.
Refer to the section "Argument Files" for more information.
<filename> — Specifies the name of a file containing command line arguments.
• -h <filename>
(optional) Concatenates header information into all design files listed with <filename>.
Allows the user to pass a large number of files to the vhencrypt utility that do not contain the
encryption information (between the `protect and `protect end directives) about how to
encrypt the file. Saves the user from editing hundreds of files to add the same encryption
information into every file.
<filename> — Specifies an existing file.

ModelSim Reference Manual, v10.1c 299

Commands
vhencrypt

• -l <filename>
(optional) Redirects log output to the file designated by <filename>.
<filename> — Specifies a file for saving output.
• -o <filename>
(optional) Combines all encrypted output into a single file.
<filename> — Specifies a file for saving output.
• -p <prefix>
(optional) Prepends encrypted file names with a prefix.
<prefix> — Any alpha-numeric string.
• -quiet
(optional) Disables encryption messages.
Related Topics
• vencrypt
• "Protecting Your Source Code" in the User’s Manual

300 ModelSim Reference Manual, v10.1c

Commands
view

view
This command opens the specified window. If you specify this command without arguments it
returns a list of all open windows in the current layout.
To remove a window, use the noview command.
The view command with one or more options and no window names specified applies the
options to the currently open windows. See examples for additional details.
Syntax
view <window_type>…[-aliases][-names] [-title {New Window Title}]
[-undock {[-icon] [-height <n>] [-width <n>] [-x <n>] [-y <n>]} | -dock]
Arguments
• <window_type>…
(required) Specifies the window type to view. You do not need to type the full type name
(see the examples below); implicit wildcards are accepted; multiple window types are
accepted. Available window types are:
assertions atv browser calltree
canalysis capacity classgraph classtree
covergroups dataflow details duranked
exclusions fcovers files fsmcoverage
fsmlist fsmview instance library
list locals memdata memory
msgviewer objects process profiledetails
project ranked runmgr schematic
source stackview structural structure
tracker transaction transcript watch
wave
Not all windows are available with all variants (ModelSim SE, ModelSim PE, Questa
SV/AFV, and so on)
• -aliases
(optional) Returns a list of <window_type> aliases.
• -height <n>
(optional) Specifies the window height in pixels. Can only be used with the -undock switch.
<n> — Any non-negative integer.

ModelSim Reference Manual, v10.1c 301

Commands
view

• -icon
(optional) Toggles the view between window and icon. Can only be used with the -undock
switch.
• -names
(optional) Returns a list of valid <window_type> arguments.
• -title {New Window Title}
(optional) Specifies the window title of the designated window.
{New Window Title} — Any string. Curly braces are needed for a string containing
spaces. Double quotes (" ") can be used in place of braces, for example "New
Window Title."
• -dock
(optional) Docks the specified standalone window into the Main window.
• -undock
(optional) Opens the specified window as a standalone window, undocked from the Main
window.
• -width <n>
(optional) Specifies the window width in pixels. Can only be used with the -undock switch.
<n> — Any non-negative integer.
• -x <n>
(optional) Specifies the window upper-left-hand x-coordinate in pixels. Can only be used
with the -undock switch.
<n> — Any non-negative integer.
• -y <n>
(optional) Specifies the window upper-left-hand y-coordinate in pixels. Can only be used
with the -undock switch.
<n> — Any non-negative integer.
Examples
• Undock the Wave window from the Main window and makes it a standalone window.
view -undock wave

• Display an undocked Processes window in the upper left-hand corner of the monitor
with a window size of 300 pixels, square.
view process -undock -x 0 -y 0 -width 300 -height 300

• Display the Watch and Wave windows.

302 ModelSim Reference Manual, v10.1c

Commands
view

view w

• Display the Objects and Processes windows.

view ob pr

• Open a new Wave window with My Wave Window as its title.

view -title {My Wave Window} wave

Related Topics
• noview

ModelSim Reference Manual, v10.1c 303

Commands
virtual count

virtual count
This command reports the number of currently defined virtuals that were not read in using a
macro file.
Syntax
virtual count [-kind {implicits | explicits}] [-unsaved]
Arguments
• -kind {implicits | explicits}
(optional) Reports only a subset of virtuals.
implicits — virtual signals created internally by the product.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -unsaved
(optional) Reports the count of only those virtuals that have not been saved to a macro file.
Related Topics
• virtual define
• virtual save
• virtual show
• Virtual Objects

304 ModelSim Reference Manual, v10.1c

Commands
virtual define

virtual define
This command prints to the transcript the definition of the virtual signals, functions, or regions
in the form of a command that can be used to re-create the object.
Syntax
virtual define [-kind {implicits | explicits>] <pathname>
Arguments
• -kind {implicits | explicits}
(optional) Transcripts only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• <pathname>
(required) Specifies the path to the virtual(s) for which you want definitions, where
wildcards are allowed.
Example
• Show the definitions of all the virtuals you have explicitly created.
virtual define -kind explicits *

Related Topics
• virtual describe
• virtual show
• Virtual Objects

ModelSim Reference Manual, v10.1c 305

Commands
virtual delete

virtual delete
This command removes the matching virtuals.
Syntax
virtual delete [-kind {implicits | explicits}] <pathname>
Arguments
• -kind {implicits | explicits}
(optional) Removes only a subset of virtuals.
implicits — virtual signals created internally by the product.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• <pathname>
(required) Specifies the path to the virtual(s) you want to delete, where wildcards are
allowed.
Example
• Delete all of the virtuals you have explicitly created.
virtual delete -kind explicits *

Related Topics
• virtual signal
• virtual function
• Virtual Objects

306 ModelSim Reference Manual, v10.1c

Commands
virtual describe

virtual describe
This command prints to the transcript a complete description of the data type of one or more
virtual signals.
Similar to the existing describe command.
Syntax
virtual describe [-kind {implicits | explicits}] <pathname>
Arguments
• -kind {implicits | explicits}
(optional) Transcripts only a subset of virtuals.
implicits — virtual signals created internally by the product.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• <pathname>
(required) Specifies the path to the virtual(s) for which you want descriptions, where
wildcards are allowed.
Example
• Describe the data type of all virtuals you have explicitly created.
virtual describe -kind explicits *

Related Topics
• virtual define
• virtual show
• Virtual Objects

ModelSim Reference Manual, v10.1c 307

Commands
virtual expand

virtual expand
This command prints to the transcript a list of all the non-virtual objects contained in the
specified virtual signal(s).
You can use this to create a list of arguments for a command that does not accept or understand
virtual signals.
Syntax
virtual expand [-base] <pathname> ...
Arguments
• -base
(optional) Outputs the root signal parent in place of a subelement. For example:
vcd add [virtual expand -base myVirtualSignal]

the resulting command after substitution would be:

vcd add signala signalb signalc

• <pathname>
(required) Specifies the path to the signals and virtual signals to expand, where wildcards
are allowed and you can specify any number of paths.
Examples
• Add the elements of a virtual signal to the VCD file.
In the Tcl language, the square brackets specify that the enclosed command should be
executed first ("virtual expand …"), then the result substituted into the surrounding
command.
vcd add [virtual expand myVirtualSignal]

Therefore, if myVirtualSignal is a concatenation of signala, signalb.rec1 and signalc(5

downto 3), the resulting command after substitution would be:
vcd add signala signalb.rec1 {signalc(5 downto 3)}

The slice of signalc is enclosed in curly braces, because it contains spaces.

Related Topics
• virtual signal
• Virtual Objects

308 ModelSim Reference Manual, v10.1c

Commands
virtual function

virtual function
This command creates a new signal, known only by the GUI (not the kernel), that consists of
logical operations on existing signals and simulation time, as described in <expressionString>.
It cannot handle bit selects and slices of Verilog registers. Please see Syntax and Conventions
for more details on syntax.
If the virtual function references more than a single scalar signal, it will display as an
expandable object in the Wave and Objects windows. The children correspond to the inputs of
the virtual function. This allows the function to be "expanded" in the Wave window to see the
values of each of the input waveforms, which could be useful when using virtual functions to
compare two signal values.
Virtual functions can also be used to gate the List window display.
Note
The virtual function and virtual signal commands are interchangeable. The product will
keep track of whether you’ve created a signal or a function with the commands and
maintain them appropriately. We document both commands because the virtual save,
virtual describe, and virtual define commands will reference your virtual objects using
the correct command.

Syntax
virtual function [-env <path>] [-install <path>] [-delay <time>] {<expressionString>} <name>
Arguments
Arguments for virtual function are the same as those for virtual signal, except for the contents
of the expression string.
• -env <path>
(optional) Specifies a hierarchical context for the signal names in <expressionString> so
they don't all have to be full paths.
<path> — Specifies a relative path to the signal(s). On Windows systems the path
separator should be a forward slash (/).
• -install <path>
(optional) Causes the newly-created signal to become a child of the specified region. If
-install is not specified, the newly-created signal becomes a child of the nearest common
ancestor of all objects appearing in <expressionString>. If the expression references more
than one WLF file (dataset), the virtual signal will automatically be placed in region
virtuals:/Functions.
<path> — Specifies a relative path to the signal(s). On Windows systems the path
separator should be a forward slash (/).

ModelSim Reference Manual, v10.1c 309

Commands
virtual function

• -delay <time> <unit>

(optional) Specifies a value by which the virtual function will be delayed. You can use
negative values to look forward in time. Refer to the examples below for more details.
<time> — Specified as an integer or decimal number. Current simulation units are the
default unless specifying <unit>.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid VHDL time units are: fs, ps,
ns, us, ms, sec, min, and hr. You must enclose <time> and <unit> within curly braces
({}).
• {<expressionString>}
(required) A text string expression, enclosed in curly braces ({ }) using the
GUI_expression_format.
• <name>
(required) The name you define for the virtual signal.
Case is ignored unless installed in a Verilog region.
Use alpha, numeric, and underscore characters only, unless you are using VHDL extended
identifier notation.
If using VHDL extended identifier notation, <name> needs to be quoted with double quotes
(" ") or with curly braces ({ }).
Examples
• Create a signal /chip/section1/clk_n that is the inverse of /chip/section1/clk.
virtual function { not /chip/section1/clk } clk_n

• Create a std_logic_vector equivalent of a Verilog register rega and installs it as

/chip/rega_slv.
virtual function -install /chip { (std_logic_vector) chip.vlog.rega
} rega_slv

• Create a boolean signal /chip/addr_eq_fab that is true when /chip/addr[11:0] is equal to

hex "fab", and false otherwise. It is acceptable to mix VHDL signal path notation with
Verilog part-select notation.
virtual function { /chip/addr[11:0] == 0xfab } addr_eq_fab

• Create a signal that is high only during times when signal /chip/siga of the gate-level
version of the design does not match /chip/siga of the rtl version of the design. Because
there is no common design region for the inputs to the expression, siga_diff is installed
in region virtuals:/Functions. The virtual function siga_diff can be added to the Wave
window, and when expanded will show the two original signals that are being
compared.

310 ModelSim Reference Manual, v10.1c

Commands
virtual function

virtual function { gate:/chip/siga XOR rtl:/chip/siga } siga_diff

• Create a virtual signal consisting of the logical "AND" function of /top/signalA with
/top/signalB, and delays it by 10 ns.
virtual function -delay {10 ns} {/top/signalA AND /top/signalB}
myDelayAandB

• Create a one-bit signal outbus_diff which is non-zero during times when any bit of
/chip/outbus in the gate-level version doesn’t match the corresponding bit in the rtl
version.
This expression uses the "OR-reduction" operator, which takes the logical OR of all the
bits of the vector argument.
virtual function { | (gate:/chip/outbus XOR rtl:/chip/outbus) }
outbus_diff

Commands fully compatible with virtual functions

add log and log delete describe
examine find restart
searchlog show

Commands not compatible with virtual functions

drivers force noforce
vcd add when

Related Topics
• virtual count • virtual define • virtual delete
• virtual describe • virtual expand • virtual hide
• virtual log • virtual nohide • virtual nolog
• virtual region • virtual save • virtual show
• virtual signal • virtual type • Virtual Objects

ModelSim Reference Manual, v10.1c 311

Commands
virtual hide

virtual hide
This command causes the specified real or virtual signals to not be displayed in the Objects
window. This is used when you want to replace an expanded bus with a user-defined bus.
You make the signals reappear using the virtual nohide command.
Syntax
virtual hide { [-kind {implicits | explicits}] | [-region <path>]} <pattern>
Arguments
• -kind {implicits | explicits}
(optional) Hides only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -region <path>
(optional) Specifies a region of design space in which to look for the signal names.
<path> — Specifies an absolute or relative path to the signal(s). On Windows systems
the path separator should be a forward slash (/).
• <pattern>
(required) Indicates which signal names or wildcard patterns should be used in finding the
signals to hide, where wildcards are allowed and you can specify any number of names or
patterns.
Related Topics
• virtual nohide
• Virtual Objects

312 ModelSim Reference Manual, v10.1c

Commands
virtual log

virtual log
This command causes the simulation-mode dependent signals of the specified virtual signals to
be logged by the kernel.
If wildcard patterns are used, it will also log any normal signals found, unless the -only option is
used. You unlog the signals using the virtual nolog command.
Syntax
virtual log [-kind {implicits | explicits}] | [-region <path>] [-recursive] [-only] [-in] [-out]
[-inout] [-internal] [-ports] <pattern>
Arguments
• -kind {implicits | explicits}
(optional) Logs only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -region <path>
(optional) Specifies a region of design space in which to look for signals to log.
<path> — Specifies an absolute or relative path to the signal(s). On Windows systems
the path separator should be a forward slash (/).
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region.
• -only
(optional) Specify that only virtual signals (as opposed to all signals) found by a <pattern>
containing a wildcard should be logged.
• -in
(optional) Specifies that the kernel log data for ports of mode IN whose names match the
specification.
• -out
(optional) Specifies that the kernel log data for ports of mode OUT whose names match the
specification.
• -inout
(optional) Specifies that the kernel log data for ports of mode INOUT whose names match
the specification.

ModelSim Reference Manual, v10.1c 313

Commands
virtual log

• -internal
(optional) Specifies that the kernel log data for internal (non-port) objects whose names
match the specification.
• -ports
(optional) Specifies that the kernel log data for all ports. Optional.
• <pattern>
(required) Indicates which signal names or wildcard patterns should be used in finding the
signals to log, where you can specify any number of names or wildcard patterns.
Related Topics
• virtual nolog
• Virtual Objects

314 ModelSim Reference Manual, v10.1c

Commands
virtual nohide

virtual nohide
This command reverses the effect of a virtual hide command, causing the specified real or
virtual signals to reappear the Objects window.
Syntax
virtual nohide { [-kind {implicits | explicits}] | [-region <path>] } <pattern>
Arguments
• -kind {implicits | explicits}
(optional) Unhides only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -region <path>
(optional) Specifies a region of design space in which to look for the signal names.
<path> — Specifies an absolute or relative path to the signal(s). On Windows systems
the path separator should be a forward slash (/).
• <pattern>
(required) Indicates which signal names or wildcard patterns should be used in finding the
signals to hide, where wildcards are allowed and you can specify any number of names or
patterns.
Related Topics
• virtual hide
• Virtual Objects

ModelSim Reference Manual, v10.1c 315

Commands
virtual nolog

virtual nolog
This command reverses the effect of a virtual log command. It causes the simulation-dependent
signals of the specified virtual signals to be excluded ("unlogged") by the kernel.
If wildcard patterns are used, it will also unlog any normal signals found, unless the -only
option is used.
Syntax
virtual nolog { [-kind {implicits | explicits}] | [-region <path>]} [-recursive] [-only] [-in] [-out]
[-inout] [-internal] [-ports] <pattern>
Arguments
• -kind {implicits | explicits}
(optional) Excludes only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -region <path>
(optional) Specifies a region of design space in which to look for signals to unlog.
<path> — Specifies an absolute or relative path to the signal(s). On Windows systems
the path separator should be a forward slash (/).
• -recursive
(optional) Specifies that the scope of the search is to descend recursively into subregions. If
omitted, the search is limited to the selected region.
• -only
(optional) Specify that only virtual signals (as opposed to all signals) found by a <pattern>
containing a wildcard should be unlogged.
• -in
(optional) Specifies that the kernel exclude data for ports of mode IN whose names match
the specification.
• -out
(optional) Specifies that the kernel exclude data for ports of mode OUT whose names match
the specification.
• -inout
(optional) Specifies that the kernel exclude data for ports of mode INOUT whose names
match the specification.

316 ModelSim Reference Manual, v10.1c

Commands
virtual nolog

• -internal
(optional) Specifies that the kernel exclude data for internal (non-port) objects whose names
match the specification.
• -ports
(optional) Specifies that the kernel exclude data for all ports.
• <pattern>
(required) Indicates which signal names or wildcard patterns should be used in finding the
signals to unlog, where wildcards are allowed and you can specify any number of names or
patterns.
Related Topics
• virtual log
• Virtual Objects

ModelSim Reference Manual, v10.1c 317

Commands
virtual region

virtual region
This command creates a new user-defined design hierarchy region.
Note
Virtual regions cannot be used in the when command.

Syntax
virtual region <parentPath> <regionName>
Arguments
• <parentPath>
(required) The full path to the region that will become the parent of the new region.
• <regionName>
(required) The name you want for the new region.
Related Topics
• virtual function
• virtual signal
• Virtual Objects

318 ModelSim Reference Manual, v10.1c

Commands
virtual save

virtual save
This command saves the definitions of virtuals to a file named virtual.do in the current
directory.
Syntax
virtual save [-kind {implicits | explicits}] [-append] [<filename>]
Arguments
• -kind {implicits | explicits}
(optional) Saves only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
• -append
(optional) Specifies to save only virtuals that are not already saved or weren’t read in from a
macro file. These unsaved virtuals are then appended to the specified or default file.
Optional.
• <filename>
(optional) The name of the file containing the definitions. If you don’t specify <filename>,
the default virtual filename (virtuals.do) will be used. You can specify a different default in
the pref.tcl file.
Related Topics
• virtual count
• Virtual Objects

ModelSim Reference Manual, v10.1c 319

Commands
virtual show

virtual show
This command lists the full path names of all explicitly defined virtuals.
Syntax
• virtual show [-kind {implicits | explicits}]
Arguments
• -kind {implicits | explicits}
(optional) Lists only a subset of virtuals.
implicits — virtual signals created internally by the tool.
explicits — virtual signals explicitly created by a user, such as with the virtual signal
command.
Unique abbreviations are accepted.
Related Topics
• virtual define
• virtual describe
• Virtual Objects

320 ModelSim Reference Manual, v10.1c

Commands
virtual signal

virtual signal
This command creates a new signal, known only by the GUI (not the kernel), that consists of
concatenations of signals and subelements as specified in <expressionString>.
It cannot handle bit selects and slices of Verilog registers. Please see Concatenation of Signals
or Subelements for more details on syntax.
Note
The virtual function and virtual signal commands are interchangeable. The product will
keep track of whether you’ve created a signal or a function with the commands and
maintain them appropriately. We document both commands because the virtual save,
virtual describe, and virtual define commands will reference your virtual objects using
the correct command.

Syntax
virtual signal [-env <path>] [-install <path>] [-delay <time>] {<expressionString>} <name>
Arguments
• -env <path>
(optional) Specifies a hierarchical context for the signal names in <expressionString> so
they don't all have to be full paths.
<path> — Specifies a relative path to the signal(s). On Windows systems the path
separator should be a forward slash (/).
• -install <path>
(optional) Causes the newly-created signal to become a child of the specified region. If
-install is not specified, the newly-created signal becomes a child of the nearest common
ancestor of all objects appearing in <expressionString>. If the expression references more
than one WLF file (dataset), the virtual signal will automatically be placed in region
virtuals:/Signals.
<path> — Specifies a relative path to the signal(s). On Windows systems the path
separator should be a forward slash (/).
• -delay <time> <unit>
(optional) Specifies a value by which the virtual function will be delayed. You can use
negative values to look forward in time. Refer to the examples below for more details.
<time> — Specified as an integer or decimal number. Current simulation units are the
default unless specifying <unit>.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid VHDL time units are: fs, ps,
ns, us, ms, sec, min, and hr. You must enclose <time> and <unit> within curly braces
({}).

ModelSim Reference Manual, v10.1c 321

Commands
virtual signal

• {<expressionString>}
(required) A text string expression, enclosed in curly braces ({ }) using the
GUI_expression_format.
• <name>
(required) The name you define for the virtual signal.
Case is ignored unless installed in a Verilog region.
Use alpha, numeric, and underscore characters only, unless you are using VHDL extended
identifier notation.
If using VHDL extended identifier notation, <name> needs to be quoted with double quotes
(" ") or with curly braces ({ }).
Examples
• Reconstruct a bus sim:/chip/alu/a(4 downto 0), using VHDL notation, assuming that
a_ii are all scalars of the same type.
virtual signal -env sim:/chip/alu { (concat_range (4 downto 0))(a_04
& a_03 & a_02 & a_01 & a_00) } a

• Reconstruct a bus sim:chip.alu.a[4:0], using Verilog notation. Note that the

concatenation notation starts with "&{" rather than "{".
virtual signal -env sim:chip.alu
{ (concat_range [4:0])&{a_04, a_03, a_02, a_01, a_00} } a

• Create a signal sim:/testbench/stuff which is a record type with three fields

corresponding to the three specified signals. The example assumes /chipa/mode is of
type integer, /chipa/alu/a is of type std_logic_vector, and /chipa/decode/inst is a user-
defined enumeration.
virtual signal -install sim:/testbench
{ /chipa/alu/a(19 downto 13) & /chipa/decode/inst & /chipa/mode }
stuff

• Create a virtual signal that is the same as /top/signalA except it is delayed by 10 ps.
virtual signal -delay {10 ps} {/top/signalA} myDelayedSignalA

• Create a three-bit signal, chip.address_mode, as an alias to the specified bits.

virtual signal { chip.instruction[23:21] } address_mode

• Concatenate signals a, b, and c with the literal constant ‘000’.

virtual signal {a & b & c & 3'b000} myextendedbus

• Add three missing bits to the bus num, creates a virtual signal fullbus, and then adds that
signal to the Wave window.

322 ModelSim Reference Manual, v10.1c

Commands
virtual signal

virtual signal {num & "000"} fullbus

add wave -unsigned fullbus

• Reconstruct a bus that was fragmented by synthesis and is missing the lower three bits.
Note that you would have to type in the actual bit names (i.e. num28, num27, and so on)
represented by the … in the syntax above.
virtual signal { num31 & num30 & num29 & ... & num4 & num3 & "000" }
fullbus
add wave -unsigned fullbus

• Create a two-bit signal (with an enumerated type) based on the results of the
subexpressions. For example, if aold equals anew, then the first bit is true (1).
Alternatively, if bold does not equal bnew, the second bit is false (0). Each
subexpression is evaluated independently.
virtual signal {(aold == anew) & (bold == bnew)} myequalityvector

• Create signal newbus that is a concatenation of bus1 (bit-reversed) and bus2[7:4] (bit-
reversed). Assuming bus1 has indices running 7 downto 0, the result will be
newbus[11:0] with the upper 8 bits being bus1[0:7] and the lower 4 bits being bus2[4:7].
See Concatenation Directives for further details.
virtual signal {(concat_reverse)(bus1 & bus2[7:4])} newbus

Commands fully compatible with virtual signals

add list add log or log add wave
delete describe examine
find force and noforce restart
searchlog show

Commands compatible with virtual signals using [virtual expand <signal>]

drivers vcd add

Commands not currently compatible with virtual signals

when

ModelSim Reference Manual, v10.1c 323

Commands
virtual signal

Related Topics
• virtual count • virtual define • virtual delete
• virtual describe • virtual expand • virtual hide
• virtual log • virtual nohide • virtual nolog
• virtual region • virtual save • virtual show
• virtual function • virtual type • Virtual Objects

324 ModelSim Reference Manual, v10.1c

Commands
virtual type

virtual type
This command creates a new enumerated type known only by the GUI, not the kernel. Virtual
types are used to convert signal values to character strings. The command works with signed
integer values up to 64 bits.
Virtual types cannot be used in the when command.
Note
If you are using SystemVerilog, you can also convert signal values to character strings
using associative arrays in your code. See the SystemVerilog LRM for more information.

Syntax
virtual type -delete <name> | {<list_of_strings>} <name>
Arguments
• -delete <name>
(Required if not defining a type.) Deletes a previously defined virtual type.
<name> — The name you gave the virtual type when you originally defined it. .
• {<list_of_strings>}
(Required if -delete is not used.) A list of values and their associated character strings.
Values can be expressed in decimal or based notation and can include "don’t-cares" (see
examples below). Three kinds of based notation are supported: Verilog, VHDL, and C-
language styles. The values are interpreted without regard to the size of the bus to be
mapped. Bus widths up to 64 bits are supported.
If the string contains spaces the string must be enclosed in quotation marks ( ““ ) If they
contain special characters square brackets, curly braces, backslashes…), they need to be
quoted within curly braces.
See the examples below for further syntax.
• <name>
(Required if -delete is not used.) The user-defined name of the virtual type. Case is not
ignored. Use alpha, numeric, and underscore characters only, unless you are using VHDL
extended identifier notation. If using VHDL extended identifier notation, <name> needs to
be quoted with double quotes (" ") or with curly braces ({ }).
Examples
• Using positional notation, associates each string with an enumeration index, starting at
zero and increasing by one in the positive direction.When myConvertedSignal is
displayed in the Wave, List, or Objects window, the string "state0" will appear when
mysignal == 0, "state1" when mysignal == 1, "state2" when mysignal == 2, and so on.

ModelSim Reference Manual, v10.1c 325

Commands
virtual type

virtual type {state0 state1 state2 state3} mystateType

virtual function {(mystateType)mysignal} myConvertedSignal
add wave myConvertedSignal

• Use sparse mapping of bus values to alphanumeric strings for an 8-bit, one-hot
encoding. It shows the variety of syntax that can be used for values. The value "default"
has special meaning and corresponds to any value not explicitly specified.
virtual type {{0 NULL_STATE} {1 st1} {2 st2} {0x04 st3} {16'h08 st4} \
{'h10 st5} {16#20 st6} {0b01000000 st7} {0x80 st8} \
{default BAD_STATE}} myMappedType
virtual function {(myMappedType)mybus} myConvertedBus
add wave myConvertedBus

• Delete the virtual type "mystateType".

virtual type -delete mystateType

• Create a virtual type that includes "don’t-cares" (the ‘-’ character).

virtual type {{0x01-- add}{0x02-- sub}{default bad}} mydecodetype

• Create a virtual type using a mask for "don’t-cares." The middle field is the mask, and
the mask should have bits set to 1 for the bits that are don't care.
virtual type {{0x0100 0xff add}{0x0200 0xff sub}{default bad}}
mydecodetype

Related Topics
• virtual function
• Virtual Objects

326 ModelSim Reference Manual, v10.1c

Commands
vlib

vlib
The command creates a design library. You must use vlib rather than operating system
commands to create a library directory or index file.
If the specified library already exists as a valid ModelSim library, the vlib command will exit
with a warning message without touching the library.
This command provides additional information with the -help switch.

Syntax
vlib [-archive [-compact <percent>]] [-format { 1 | 3 }] [-dos | -short | -unix | -long]
[(-lock | -unlock) <design_unit>] [-locklib | -unlocklib] <name>
Arguments
• -archive [-compact <percent>]
(optional) Stores design units that are compiled into the created library in archives rather
than in subdirectories. Refer to “Archives” for more details.
You may optionally specify a decimal number between 0 and 1 that denotes the allowed
percentage of wasted space before archives are compacted. By default archives are
compacted when 50% (.5) of their space is wasted. See an example below.
-compact — (optional) Specifies the percentage amount of wasted space before the
archives are compacted where the default is 50% (0.5).
<percent> — specified as a decimal number betwen 0 and 1.
• -format { 1 | 3 }
(optional) Prepares a library for conversion to be compatible with a previous release, by
altering the _info file.
1 — allows you to convert a library to be compatible with the 6.2 series and earlier.
3 — allows you to convert a library to be compatible with the 6.3 series and newer.
The usage flow would be:
\\1) Using a current release of the simulator, run:
vlib -format 1 current_lib
vcom -refresh -work current_lib
\\ to prepare current_lib for conversion back to a 6.2 release
\\
\\2) Using a 6.2 release of the simulator, run:
vcom -refresh -work current_lib
\\ to refresh current_lib for use with the previous release

• -dos
(optional) Specifies that subdirectories in a library have names that are compatible with
DOS. Not recommended if you use the vmake utility. .

ModelSim Reference Manual, v10.1c 327

Commands
vlib

• -short
(optional) Interchangeable with the -dos argument.
• -unix
(optional) Specifies that subdirectories in a library may have long file names that are NOT
compatible with DOS.
• -long
(optional) Interchangeable with the -unix argument.
• (-lock | -unlock) <design_unit>
(optional) Locks an existing design unit so it cannot be recompiled or refreshed. The
-unlock switch reverses this action. File permissions are not affected by these switches.
• -locklib | -unlocklib
(optional) Locks a complete library so that compilation cannot target the library and the
library cannot be refreshed. The -unlocklib switch reverses this action. File permissions are
not affected by these switches.
• <name>
(required) Specifies the pathname or archive name of the library to be created.
Examples
• Create the design library design. You can define a logical name for the library using the
vmap command or by adding a line to the library section of the modelsim.ini file that is
located in the same directory.
vlib design

• Create the design library uut and specifies that any design units compiled into the library
are created as archives. Also specifies that each archive be compacted when 30% of its
space is wasted.
vlib -archive -compact .3 uut

328 ModelSim Reference Manual, v10.1c

Commands
vlog

vlog
The vlog command compiles Verilog source code and SystemVerilog extensions into a
specified working library (or to the work library by default).
The vlog command may be invoked from within ModelSim or from the operating system
command prompt. It may also be invoked during simulation.
Compiled libraries are major-version dependent. When moving between major versions, you
have to refresh compiled libraries using the -refresh argument to vlog. This is not true for minor
versions (letter releases).
All arguments to the vlog command are case sensitive: -WORK and -work are not equivalent.
The IEEE P1800 Draft Standard for SystemVerilog requires that the default behavior of the
vlog command is to treat each Verilog design file listed on the command line as a separate
compilation unit. This behavior is a change in vlog from versions prior to 6.2, wherein all files
in a single command line were concatenated into a single compilation unit. To treat multiple
files listed within a single command line as a single compilation unit, use either the vlog -mfcu
argument or the MultiFileCompilationUnit modelsim.ini file variable.
This command provides additional information with the -help switch.

Syntax
vlog [options] <filename> [<filename> ...]
[options]:
[-93]
[-addpragmaprefix <prefix>]
[-compat] [-compile_uselibs[=<directory_name>]]
[-convertallparams] [-cuname]
[+define+<macro_name>[=<macro_text>]] [-deglitchalways | -nodeglitchalways]
[+delay_mode_distributed] [+delay_mode_path] [+delay_mode_unit]
[+delay_mode_zero] [-dpiforceheader] [-dpiheader <filename>]
[-E <filename>] [-Edebug <filename>] [-enumfirstinit] [-Epretty <filename>]
[-error <msg_number>[,<msg_number>,…]]
[-f <filename>] [-force_refresh <design_unit>]
[-fsmimplicittrans | -nofsmimplicittrans]
[-fsmresettrans | -nofsmresettrans ] [-fsmsingle | -nofsmsingle]
[-fsmverbose[b | t | w]] [-fsmxassign | -nofsmxassign ]
[-gen_xml <design_unit> <filename>]
[-hazards]
[-ignorepragmaprefix <prefix>] [+incdir+<directory>] [-incr | -noincr]
[-isymfile]

ModelSim Reference Manual, v10.1c 329

Commands
vlog

[-l <filename>] [+libcell | +nolibcell]

[+libext+<suffix>] [-libmap <pathname>] [-libmap_verbose] [+librescan]
[-line <number>] [-lint] [-lrmclassinit]
[+maxdelays] [+mindelays] [-mixedansiports]
[-mixedsvvh [b | s | v]] [-mfcu | -sfcu] [-modelsimini <ini_filepath>]
[-nodbgsym]
[-noexcludeternary <design_unit>]
[-noForceUnsignedToVhdlInteger] [-nologo] [+nospecify]
[-note <msg_number>[,<msg_number>,…]] [+notimingchecks]
[-novtblfixup] [+nowarn<CODE>] [-nowarn <category_number>]

[-oldsv] [-override_timescale <time_unit> / <time_precision>] [-O0]

[-pedanticerrors] [-permissive] [-permit_defunct_sv] [-printinfilenames]
[-quiet]
[-R [<simargs>]] [-refresh]
[-source] [-s] [-sv]
[-svext[=[+|-]<extension>[,[+|-]<extension>]*]] [-svinputport=net | var | relaxed]
[-skipprotected] [-skipprotectedmodule]
[-suppress <msg_number>[,<msg_number>,…]]
[-sv05compat] [-sv09compat] [-sv12compat]
[-time] [-timescale <time_units>/<time_precision>]
[+typdelays]
[-u]
[-v <library_file>] [-version] [-vlog01compat] [-vlog95compat] [-vmake]

[-warning <msg_number>[,<msg_number>,…]] [-work <library_name>]

[-writetoplevels <fileName>]
[-y <library_directory>]
Arguments
• -93
Specifies that the VHDL interface to Verilog modules use VHDL 1076-1993 extended
identifiers to preserve case in Verilog identifiers that contain uppercase letters. Optional.
• -addpragmaprefix <prefix>
(optional) Enables recognition of synthesis and coverage pragmas with a user specified
prefix. If this argument is not specified, pragmas are treated as comments. All regular
synthesis and coverage pragmas are honored.
<prefix> — Specifies a user defined string where the default is no string, indicated by
quotation marks (““).

330 ModelSim Reference Manual, v10.1c

Commands
vlog

You may also set this with the AddPragmaPrefix variable in the vlog section of the
modelsim.ini file.
• -compat
Disables optimizations that result in different event ordering than Verilog-XL. Optional.
ModelSim Verilog generally duplicates Verilog-XL event ordering, but there are cases
where it is inefficient to do so. Using this option does not help you find event order
dependencies, but it allows you to ignore them. Keep in mind that this option does not
account for all event order discrepancies, and that using this option may degrade
performance. Refer to “Event Ordering in Verilog Designs” for additional information.
• -compile_uselibs[=<directory_name>]
Locates source files specified in a `uselib directive (Refer to “Verilog-XL uselib Compiler
Directive”), compiles those files into automatically created libraries, and updates the
modelsim.ini file with the logical mappings to the new libraries. Optional. If a
directory_name is not specified, ModelSim uses the name specified in the
MTI_USELIB_DIR environment variable. If that variable is not set, ModelSim creates the
directory mti_uselibs in the current working directory.
• -convertallparams
Enables converting parameters not defined in ANSI style to VHDL generics of type
std_logic_vector, bit_vector, std_logic, vl_logic, vl_logic_vector, and bit. Optional.
• -cuname
Used only in conjunction with -mfcu. Optional. The -cuname names the compilation unit
being created by vlog. The named compilation unit can then be specified on the vsim
command line, along with the <top> design unit. The purpose of doing so is to force
elaboration of specified compilation unit package, thereby forcing elaboration of a
necessary ‘bind’ statement within that compilation unit that would otherwise not be
elaborated. An example of the necessary commands is:
vlog -cuname pkg_name -mfcu file1.sv file2.sv
vsim top pkg_name

You need to do this only in cases where you have a ‘bind’ statement in a module that might
otherwise not be elaborated, because no module in the design depends on that compilation
unit. In other words, if a module that depends on that compilation unit exists, you don’t need
to force the elaboration, for it occurs automatically. Also, if you are using qverilog to
compile and simulate the design, this binding issue is handled properly automatically.
• +define+<macro_name>[=<macro_text>]
Allows you to define a macro from the command line that is equivalent to the following
compiler directive:
`define <macro_name> <macro_text>

Optional. You can specify more than one macro with a single +define. For example:

ModelSim Reference Manual, v10.1c 331

Commands
vlog

vlog +define+one=r1+two=r2+three=r3 test.v

A command line macro overrides a macro of the same name defined with the `define
compiler directive.
• -deglitchalways | -nodeglitchalways
Reduces the incidents of zero delay oscillations among always_comb and always @*
combinatorial logic blocks that produce glitches on the variables they write. This is the
default behavior. Old behavior may be selected with the vlog -nodeglitchalways option. A
side effect of this behavior is that time zero races involving the glitch-producing always
blocks may resolve in a different order.
• +delay_mode_distributed
Disables path delays in favor of distributed delays. Optional. Refer to “Delay Modes” for
details.
• +delay_mode_path
Sets distributed delays to zero in favor of using path delays. Optional.
• +delay_mode_unit
Sets path delays to zero and non-zero distributed delays to one time unit. Optional.
• +delay_mode_zero
Sets path delays and distributed delays to zero. Optional.
• -dpiforceheader
(optional) Forces the generation of a DPI header file even if it will be empty of function
prototypes.
• -dpiheader <filename>
(optional) Generates a header file that may then be included in C source code for DPI import
functions. Refer to “DPI Use Flow” for additional information.
• -E <filename>
(optional) Captures text processed by the Verilog parser after preprocessing has occurred
and copies that text to an output file. This includes text read from source files specified by
using the -v or -y argument.
<filename> — Specifies a name for the debugging output file. Wildcards are not
allowed.
Generally, preprocessing consists of the following compiler directives: `ifdef, `else, `elsif,
`endif, `ifndef, `define, `undef, `include.
The `line directive attempts to preserve line numbers, file names, and level in the output file
(per the 1800-2009 LRM). White space is usually preserved, but sometimes it may be
deleted or added to the output file.

332 ModelSim Reference Manual, v10.1c

Commands
vlog

• -Edebug <filename>
(optional) Captures text processed by the Verilog parser after preprocessing has occurred
and copies that text to a debugging output file.
<filename> — Specifies a name for the debugging output file. Wildcards are not
allowed.
Generally, preprocessing consists of the following compiler directives: `ifdef, `else, `elsif,
`endif, `ifndef, `define, `undef, `include. The file is a concatenation of source files with
`include expanded. The file can be compiled and then used to find errors in the original
source files. The `line directive attempts to preserve line numbers and file names in the
output file. White space is usually preserved, but sometimes it may be deleted or added to
the output file.
• -enumfirstinit
(optional) Initializes enum variables in SystemVerilog using the leftmost value as the
default. You must also use the argument with the vsim command in order to implement this
initialization behavior. Specify the EnumBaseInit variable as 0 in the modelsim.ini file to set
this as a permanent default.
• -Epretty <filename>
Captures text processed by the Verilog parser after preprocessing has occurred, performs
some formatting for better readability, and copies that text to an output file, <filename>.
Optional.
• -error <msg_number>[,<msg_number>,…]
Changes the severity level of the specified message(s) to "error." Optional. Edit the error
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
• -f <filename>
Specifies a file with more command line arguments. Optional. Allows complex arguments
to be reused without retyping. Allows gzipped input files. Nesting of -f options is allowed.
Refer to the section "Argument Files" for more information.
• -force_refresh <design_unit>
Forces the refresh of all specified design units. Optional. By default, the work library is
updated; use -work <library_name>, in conjunction with -force_refresh, to update a
different library (for example, vlog -work <your_lib_name> -force_refresh).
When the compiler refreshes a design unit, it checks each dependency to ensure its source
has not been changed and recompiled. Sometimes the dependency checking algorithm
changes from release to release. This can lead to false errors during the integrity checks
performed by the -refresh argument. An example of such a message follows:
** Error: (vsim-13) Recompile /u/test/dware/dware_61e_beta.dwpackages
because /home/users/questasim/linux/../synopsys.attributes has changed.

ModelSim Reference Manual, v10.1c 333

Commands
vlog

The -force_refresh argument forces the refresh of the design unit, overriding any
dependency checking errors encountered by the -refresh argument.
A more conservative approach to working around -refresh dependency checks is to
recompile the source code, if it is available.
• -fsmimplicittrans | -nofsmimplicittrans
(optional) Toggles recognition of implied same state transitions. This setting is off by
default.
• -fsmresettrans | -nofsmresettrans
(optional) Toggles recognition of synchronouos or asynchronous reset transitions. This
includes/excludes reset transitions in coverage results. This setting is on by default.
• -fsmsingle | -nofsmsingle
(optional) Toggles the recognition of VHDL FSMs where the current state variable of type
std_logic, bit, boolean, or single-bit std_logic_vector/bit_vector and Verilog single-bit
FSMs. This setting is off by default.
• -fsmverbose[b | t | w]
Provides information about FSMs detected, including state reachability analysis. Optional.
b — displays only basic information.
t — displays a transition table in addition to the basic information.
w — displays any warning messages in addition to the basic information.
When you do not specify an argument, this switch reports all information similar to:
# ** Note: (vlog-1947) FSM RECOGNITION INFO
# Fsm detected in : ../fpu/rtl/vhdl/serial_mul.vhd
# Current State Variable : s_state :
../fpu/rtl/vhdl/serial_mul.vhd(76)
# Clock : clk_i
# Reset States are: { waiting , busy }
# State Set is : { busy , waiting }
# Transition table is
# -------------------------------------------
# busy => waiting Line : (114 => 114)
# busy => busy Line : (111 => 111)
# waiting => waiting Line : (120 => 120) (114 => 114)
# waiting => busy Line : (111 => 111)
# -------------------------------------------

When you do not specify this switch, you will receive a message similar to:
# ** Note: (vlog-143) Detected '1' FSM/s in design unit
'serial_mul.rtl'.

• -fsmxassign | -nofsmxassign
(optional) Toggles recognition of finite state machines (FSMs) containing X assignment.
This option is used to detect FSMs if current state variable or next state variable has been
assigned "X" value in a "case" statement. FSMs containing X-assign are otherwise not
detectable. This setting is on by default.

334 ModelSim Reference Manual, v10.1c

Commands
vlog

• -gen_xml <design_unit> <filename>

Produces an XML-tagged file containing the interface definition of the specified module.
Optional. This option requires a two-step process where you must 1) compile <filename>
into a library with vlog (without -gen_xml) then 2) execute vlog with the -gen_xml switch,
for example:
vlib work
vlog counter.v
vlog -gen_xml counter counter.xml

• -hazards
Detects event order hazards involving simultaneous reading and writing of the same register
in concurrently executing processes. Optional. You must also specify this argument when
you simulate the design with vsim. Refer to “Hazard Detection” for more details.
Note
Enabling -hazards implicitly enables the -compat argument. As a result, using this
argument may affect your simulation results.

• -ignorepragmaprefix <prefix>
(optional) Directs vlog to ignore synthesis and coverage pragmas with the specified
prefixname. All affected pragmas will be treated as regular comments. Edit the
IgnorePragmaPrefix modelsim.ini variable to set a permanent default.
<prefix> — Specifies a user defined string.
• +incdir+<directory>
Specifies directories to search for files included with `include compiler directives. Optional.
By default, the current directory is searched first and then the directories specified by the
+incdir options in the order they appear on the command line. You may specify multiple
+incdir options as well as multiple directories separated by "+" in a single +incdir option.
• -incr
Performs an incremental compilation. Optional. Compiles only code that has changed. For
example, if you change only one module in a file containing several modules, only the
changed module will be recompiled. Note however that if the compile options change, all
modules are recompiled, regardless of whether you use vlog -incr or not.
• -isymfile
Generates a complete list of all imported tasks and functions (TFs). Used with DPI to
determine all imported TFs that are expected by ModelSim.
• -l <filename>
(optional) Generates a log file of the compile.

ModelSim Reference Manual, v10.1c 335

Commands
vlog

• +libcell | +nolibcell
+libcell — Treats all modules found and compiled by source library search as though
they contained a ‘celldefine compiler directive, thus marking them as cells (refer to
the -v and -y arguments of vlog, which enable source library search). Using the
+libcell argument matches historical behavior of Verilog-XL with respect to source
library search. Optional.
+nolibcell — (default) Disables treating all modules found and compiled by source
library search as though they contained a ‘celldefine compiler directive. That is, this
argument restores the default library search behavior if you have changed it using the
+libcell | +nolibcell argument. Optional.
Note
By default, wildcard logging and code coverage exclude cells. For more information,
refer to the -nocovercells and -covercells arguments of vlog and to the description of
wildcard logging performed by the log command.

• +libext+<suffix>
Works in conjunction with the -y option. Specifies file extensions for the files in a source
library directory. Optional. By default, the compiler searches for files without extensions. If
you specify the +libext argument, then the compiler will search for a file with the suffix
appended to an unresolved name. You may specify only one +libext option, but it may
contain multiple suffixes separated by the plus character (+). The extensions are tried in the
order you specify them with the +libext argument.
• -libmap <pathname>
Specifies a Verilog 2001 library map file. Optional. You can omit this argument by placing
the library map file as the first option on the vlog invocation (e.g., vlog top.map top.v
top_cfg.v).
• -libmap_verbose
Displays library map pattern matching information during compilation. Optional. Use to
troubleshoot problems with matching filename patterns in a library file.
• +librescan
Scans libraries in command-line order for all unresolved modules. Optional.
• -line <number>
Starts the compiler on the specified line in the Verilog source file. Optional. By default, the
compiler starts at the beginning of the file.
• -lint
(optional) Issues warnings on the following lint-style static checks:
o when Module ports are NULL.
o when assigning to an input port.

336 ModelSim Reference Manual, v10.1c

Commands
vlog

o when referencing undeclared variables/nets in an instantiation.

This switch generates additional array bounds-checking code, which can slow down
simulation, to check for the following:
o index warnings for dynamic arrays
o when an index for a Verilog unpacked variable array reference is out of bounds.
The warnings are reported as WARNING[8]. You can also enable this option using the
Show_Lint variable in the modelsim.ini file.
• -lrmclassinit
Changes initialization behavior to match the SystemVerilog specification (per IEEE Std
1800-2007) where all superclass properties will be initialized before any subclass
properties.
• +maxdelays
Selects maximum delays from the "min:typ:max" expressions. Optional. If preferred, you
can defer delay selection until simulation time by specifying the same option to the
simulator.
• +mindelays
Selects minimum delays from the "min:typ:max" expressions. Optional. If preferred, you
can defer delay selection until simulation time by specifying the same option to the
simulator.
• -mixedansiports
Permits partial port redeclarations.
• -mixedsvvh [b | s | v]
Facilitates using SystemVerilog packages at the SystemVerilog-VHDL boundary of a
mixed-language design. When you compile a SystemVerilog package with -mixedsvvh, the
package can be included in a VHDL design as if it were defined in VHDL itself. Optional.
b — treats all scalars/vectors in the package as VHDL bit/bit_vector
s — treats all scalars/vectors in the package as VHDL std_logic/std_logic_vector
v — treats all scalars/vectors in the package as VHDL vl_logic/vl_logic_vector
• -mfcu
Instructs the compiler to treat all files within a compilation command line as a single
compilation unit. Optional. The default behavior is to treat each file listed in a command as
a separate compilation unit, per the SystemVerilog standard. Prior versions concatenated the
contents of the multiple files into a single compilation unit by default. You can also enable
this option using the MultiFileCompilationUnit variable in the modelsim.ini file.

ModelSim Reference Manual, v10.1c 337

Commands
vlog

• -modelsimini <ini_filepath>
Loads an alternate initialization file that replaces the current initialization file. Overrides the
file path specified in the MODELSIM environment variable. Specifies either an absolute or
relative path to the initialization file. On Windows systems the path separator should be a
forward slash (/).
• -nodbgsym
Disables the generation of the symbols debugging database in the compiled library.
The symbols debugging database is the .dbs file in the compiled library that provides
information to the GUI allowing you to view detailed information about design objects at
the source level. Two major GUI features that use this database include source window
annotation and textual dataflow.
You should only specify this switch if you know that anyone using the library will not
require this information for design analysis purposes.
• -noexcludeternary <design_unit>
(optional) Disables the automatic exclusion of UDB coverage data rows resulting from
ternary expressions for the specified design unit. Normal operation for code coverage is to
include rows corresponding to the case where two data inputs are the same, and the select
input is a “don’t care”. To disable this automatic exclusion for the entire design, use “vsim
-noexcludeternary” instead.
• -noForceUnsignedToVhdlInteger
Prevents untyped Verilog parameters in mixed-language designs that are initialized with
unsigned values between 2*31-1 and 2*32 from being converted to a VHDL generic. By
default, untyped Verilog parameters that are initialized with unsigned values between 2*31-
1 and 2*32 are converted to VHDL INTEGER generics. Because VHDL INTEGER
parameters are signed numbers, the Verilog values 2*31-1 to 2*32 are converted to negative
VHDL values in the range from -2*31 to -1 (the 2's complement value).
• -noincr
Disables incremental compilation previously turned on with -incr argument. Optional.
Default.
• -nologo
Disables the startup banner. Optional.
• +nospecify
Disables specify path delays and timing checks. Optional.
• -note <msg_number>[,<msg_number>,…]
Changes the severity level of the specified message(s) to "note." Optional. Edit the note
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.

338 ModelSim Reference Manual, v10.1c

Commands
vlog

• +notimingchecks
Removes all timing check entries from the design as it is parsed. Optional.
• -novtblfixup
Causes virtual method calls in SystemVerilog class constructors to behave as they would in
normal class methods, which prevents the type of a this reference from changing during
construction.
This overrides default behavior, where the type of a this reference is treated as if it is a
handle to the type of the active new() method while a constructor is executing (which
implies that virtual method calls resolve will not execute methods of an uninitialized class
type).
• +nowarn<CODE>
Disables warning messages in the category specified by <CODE>. Optional. Warnings that
can be disabled include the <CODE> name in square brackets in the warning message. For
example,
** Warning: test.v(15): [RDGN] - Redundant digits in numeric
literal.

This warning message can be disabled by specifying +nowarnRDGN.

• -nowarn <category_number>
Prevents the specified message(s) from displaying. The <msg_number> is the number
preceding the message you wish to suppress. Optional. Multiple -nowarn switches are
allowed. Warnings may be disabled for all compiles via the Main window Compile >
Compile Options menu command or the modelsim.ini file (refer to modelsim.ini
Variables).
The warning message categories are described in Table 2-7:
Table 2-7. Warning Message Categories for vlog -nowarn
Category Description
number
12 non-LRM compliance in order to match Cadence behavior
13 constructs that code coverage can't handle

• -oldsv
(optional) Allows unpacked array concatenation on input ports to be treated as an
assignment pattern. Accepts constant expressions in variable loop list with the standard
foreach syntax – foreach (array[i, j, k]) – and alternate foreach syntax – foreach
(array[i][j][k]).
• -override_timescale <time_unit> / <time_precision>
Specifies a timescale for all compiled design units. This timescale overrides all ‘timescale
directives and all declarations of timeunit and timeprecision. Optional.

ModelSim Reference Manual, v10.1c 339

Commands
vlog

time_unit — unit of measurement for times and delays. This specification consists of
one of three integers (1, 10, or 100) representing order of magnitude and one of six
character strings representing units of measurement:

{1 | 10 | 100} {s | ms | us | ns | ps | fs}

For example, 10 ns.

time_precision — unit of measurement for rounding delay values before being used in
simulation. Allowable values are the same as for time_unit.
• -O0
Lower the optimization to a minimum with -O0 (capital oh zero). Optional. Use this to work
around bugs, increase your debugging visibility on a specific cell, or when you want to
place breakpoints on source lines that have been optimized out.
• -pedanticerrors
(optional) Enforces strict compliance of the IEEE Std 1800-2005 in the following cases:
• Covergroup bin size, value range, or transition specification must be constant.
• Using "new” for queues is not legal. When strict compliance is not enforced, use of
"new" creates a queue of the specified size where all elements are initialized to the
default value of the queue element type.
• Using underscore character (_) in sized, based literals is not legal. When you specify this
argument, an error will occur for literals such as 2'b_01.
• Omitting the grave accent mark (`) preceding the left brace ({) when writing structure
literals is not legal. When you specify this argument, an error will occur for literals
written without that mark.
• Inserting the grave accent mark to precede quotation marks (`") that enclose string
literals is not legal—only string literals within quotation marks (") are allowed. When
you specify this argument, an error will occur for string literals using that mark.
• Using class extern method prototypes with lifetime (automatic/static) designations
produces a compliance error (instead of a warning).
• Using “cover bool@clk” as a PSL statement.
• Using realtime data types in SystemVerilog assertions.
• Using an unsized constant in a concatenation if it is the leftmost value in the list.
This argument also produces a report of mismatched ‘else directives.
• -permissive
Allows messages in the LRM group of error messages to be downgraded to a warning.
Optional.

340 ModelSim Reference Manual, v10.1c

Commands
vlog

• -permit_defunct_sv
Allows using a selected set of constructs no longer supported by the SystemVerilog
standard. Currently, the set supports only the use of the keyword “char.” This argument
allows use of the keyword “char” to be interpreted as the SystemVerilog “byte” type.
Optional.
• -printinfilenames
Prints the path names of all source files opened (including “include” files) during the
compile. Specifies whether each file is a Verilog or SystemVerilog file.
• -quiet
Disables 'Loading' messages. Optional.
• -R [<simargs>]
Instructs the compiler to invoke vsim after compiling the design. The compiler
automatically determines which top-level modules are to be simulated. The command line
arguments following -R are passed to the simulator, not the compiler. Place the -R option at
the end of the command line or terminate the simulator command line arguments with a
single "-" character to differentiate them from compiler command line arguments.
The -R option is not a Verilog-XL option, but it is used by ModelSim to combine the
compile and simulate phases together as you may be used to doing with Verilog-XL. It is
not recommended that you regularly use this option because you will incur the unnecessary
overhead of compiling your design for each simulation run. Mainly, it is provided to ease
the transition to ModelSim.
• -refresh
Regenerates a library image. Optional. By default, the work library is updated. To update a
different library, use -work <library_name> with -refresh (for example, vlog -work
<your_lib_name> -refresh). If a dependency checking error occurs which prevents the
refresh, use the vlog -force_refresh argument. See vlog examples for more information.
You may use a specific design name with -refresh to regenerate a library image for that
design, but you may not use a file name.
• -sfcu
Instructs the compiler to treat all files within a compilation command line as a separate
compilation units. This is the default behavior and is the inverse of the behavior of -mfcu.
This switch will override the MultiFileCompilationUnit variable if it is set to "1" in the
modelsim.ini file.
• -source
Displays the associated line of source code before each error message that is generated
during compilation. Optional; by default, only the error message is displayed.

ModelSim Reference Manual, v10.1c 341

Commands
vlog

• -s
Instructs the compiler not to load the standard package. Optional. This argument should
only be used when you are compiling the sv_std package.
• -sv
Enables SystemVerilog features and keywords. Optional. By default ModelSim follows the
IEEE Std 1364-2001 and ignores SystemVerilog keywords. If a source file has a ".sv"
extension, ModelSim will automatically parse SystemVerilog keywords.
• -svext[=[+|-]<extension>[,[+|-]<extension>]*]
(optional) Enables SystemVerilog language extensions.
Where <extension> is one of the following:
feci — Treat constant expressions in a foreach loop variable index as constant.
pae — Automatically export all symbols imported and referenced in a package.
uslt — (default) Promote unused design units found in source library files specified
with the -y option to top-level design units.
spsl — (default) Search for packages in source libraries specified with -y and +libext.
Multiple extensions are specified as a comma separated list. For example:
vlog -svext=-feci,+uslt,spsl
• -svinputport=net | var | relaxed
Used in conjunction with -sv to determine the default data type assigned to an input port
declaration. Optional.
net — declares the port to be a net. This value enforces strict compliance to the Verilog
LRM (IEEE Std 1364-2005), where the port declaration defaults to wire.
var — declares the port to be a variable. This value enforces behavior from previous
releases, where the port declaration defaults to variable.
relaxed — (default) declares the port to be a net only if the type is a 4-state scalar or
4-state single dimensional vector. Otherwise, the port is declared a variable.
• -sv05compat
Used in conjunction with the -sv switch to ensure compatibility with the reserved keyword
set of IEEE Std 1800-2005.
• -sv09compat
Used in conjunction with the -sv switch to ensure compatibility with the reserved keyword
set of IEEE Std 1800-2009.
• -sv12compat
Used in conjunction with the -sv switch to ensure compatibility with the reserved keyword
set of IEEE Std 1800-2012.

342 ModelSim Reference Manual, v10.1c

Commands
vlog

• -skipprotected
Ignores any ‘protected/‘endprotected region contained in a module. Optional.
• -skipprotectedmodule
Prevents adding any module containing a ‘protected/‘endprotected region to the library.
Optional.
• -suppress <msg_number>[,<msg_number>,…]
Prevents the specified message(s) from displaying. The <msg_number> is the number
preceding the message you wish to suppress. Optional. You cannot suppress Fatal or
Internal messages. Edit the suppress variable in the modelsim.ini file to set a permanent
default. Refer to “Changing message Severity Level” for more information.
• -time
Reports the "wall clock time" vlog takes to compile the design. Optional. Note that if many
processes are running on the same system, wall clock time may differ greatly from the
actual "cpu time" spent on vlog.
• -timescale <time_units>/<time_precision>
Specifies the default timescale for modules not having an explicit timescale directive in
effect during compilation. Optional. The format of the -timescale argument is the same as
that of the `timescale directive. The format for <time_units> and <time_precision> is
<n><units>. The value of <n> must be 1, 10, or 100. The value of <units> must be fs, ps,
ns, us, ms, or s. In addition, the <time_units> must be greater than or equal to the
<time_precision>.
• +typdelays
Selects typical delays from the "min:typ:max" expressions. Default. If preferred, you can
defer delay selection until simulation time by specifying the same option to the simulator.
• -u
Converts regular Verilog identifiers to uppercase. Allows case insensitivity for module
names. Optional.
• -v <library_file>
Specifies a source library file containing module and UDP definitions. Optional. Refer to
“Verilog-XL Compatible Compiler Arguments” for more information.
After all explicit filenames on the vlog command line have been processed, the compiler
uses the -v option to find and compile any modules that were referenced but not yet defined.
Modules and UDPs within the file are compiled only if they match previously unresolved
references. Multiple -v options are allowed. See additional discussion in the examples.
• -version
Returns the version of the compiler as used by the licensing tools. Optional.

ModelSim Reference Manual, v10.1c 343

Commands
vlog

• -vlog01compat
Ensures compatibility with rules of IEEE Std 1364-2001. Default.
• -vlog95compat
Disables Verilog 2001 keywords, which ensures that code that was valid according to the
1364-1995 spec can still be compiled. By default ModelSim follows the rules of IEEE Std
1364-2001. Some requirements in 1364-2001 conflict with requirements in 1364-1995.
Optional. Edit the vlog95compat variable in the modelsim.ini file to set a permanent default.
• -vmake
Generates a complete record of all command line data and files accessed during the compile
of a design. This data is then used by the vmake command to generate a comprehensive
makefile for recompiling the design library. By default, vcom stores compile data needed
for the -refresh switch and ignores compile data not needed for -refresh. The -vmake switch
forces inclusion of all file dependencies and command line data accessed during a compile,
whether they contribute data to the initial compile or not. Executing this switch can increase
compile time in addition to increasing the accuracy of the compile. See the vmake command
for more information.
• -warning <msg_number>[,<msg_number>,…]
Changes the severity level of the specified message(s) to "warning." Optional. Edit the
warning variable in the modelsim.ini file to set a permanent default. Refer to “Changing
Message Severity Level” for more information.
• -work <library_name>
Specifies a logical name or pathname of a library that is to be mapped to the logical library
work. Optional; by default, the compiled design units are added to the work library. The
specified pathname overrides the pathname specified for work in the project file.
• -writetoplevels <fileName>
(optional) Records the names of all top level module names in a specified file. Also records
any compilation unit name specified with -cuname. May only be specified when compiling
the top level modules.
<fileName> — Required. Specifies the name of the file where module names are to be
recorded.
• -y <library_directory>
Specifies a source library directory containing definitions for modules, packages, interfaces,
and user-defined primitives (UDPs). Usually, this is a directory of source files that you want
to scan if the compiled versions do not already exist in a library. Optional. Refer to
“Verilog-XL Compatible Compiler Arguments” for more information.
After all explicit filenames on the vlog command line have been processed, the compiler
uses the -y option to find and compile any modules that were referenced but not yet defined.
Files within this directory are compiled only if the file names match the names of previously
unresolved references. Multiple -y options are allowed. You will need to specify a file suffix

344 ModelSim Reference Manual, v10.1c

Commands
vlog

by using -y in conjunction with the +libext+<suffix> option. See additional discussion in

the examples.
Note
Any -y arguments that follow a -refresh argument on a vlog command line are ignored.
Any -y arguments that come before the -refresh argument on a vlog command line are
processed.

• <filename>
Specifies the name of the Verilog source code file to compile. One filename is required.
Multiple filenames can be entered separated by spaces. Wildcards can be used.
Examples
• Compile the Verilog source code contained in the file example.vlg.
vlog example.vlg

• After compiling top.v, vlog will scan the file und1 for modules or primitives referenced
but undefined in top.v. Only referenced definitions will be compiled.
vlog top.v -v und1

• After compiling top.v, vlog will scan the vlog_lib library for files with modules with the
same name as primitives referenced, but undefined in top.v. The use of +libext+.v+.u
implies filenames with a .v or .u suffix (any combination of suffixes may be used). Only
referenced definitions will be compiled.
vlog top.v +libext+.v+.u -y vlog_lib

The -work option specifies mylib as the library to regenerate. -refresh rebuilds the
library image without using source code, allowing models delivered as compiled
libraries without source code to be rebuilt for a specific release of ModelSim.
• If your library contains VHDL design units, be sure to regenerate the library with the
vcom command using the -refresh option as well. Refer to “Regenerating Your Design
Libraries” for more information.
vlog -work mylib -refresh

• The -incr option determines whether or not the module source or compile options have
changed as module1.v is parsed. If no change is found, the code generation phase is
skipped. Differences in compile options are determined by comparing the compiler
options stored in the _info file with the compiler options given. They must match
exactly.
vlog module1.v -u -O0 -incr

ModelSim Reference Manual, v10.1c 345

Commands
vlog

• The -timescale option specifies the default timescale for module1.v, which did not have
an explicit timescale directive in effect during compilation. Quotes (" ") are necessary
because the argument contains white spaces.
vlog module1.v -timescale "1 ns / 1 ps"

346 ModelSim Reference Manual, v10.1c

Commands
vmake

vmake
The vmake utility allows you to use a UNIX or Windows MAKE program to maintain
individual libraries. You run vmake on a compiled design library. This utility operates on
multiple source files per design unit; it supports Verilog include files as well as Verilog and
VHDL PSL vunit files.
Note
If a design is spread across multiple libraries, then each library must have its own
makefile and you must build each one separately.

By default, the output of vmake is sent to stdout—however, you can send the output to a
makefile by using the shell redirect operator (>) along with the name of the file. You can then
run the makefile with a version of MAKE (not supplied with ModelSim) to reconstruct the
library. This command must be invoked from either the UNIX or the Windows/DOS prompt.
A MAKE program is included with Microsoft Visual C/C++, as well as many other program
development environments.
After running the vmake utility, MAKE recompiles only the design units (and their
dependencies) that have changed. You run vmake only once; then you can simply run MAKE
to rebuild your design. If you add new design units or delete old ones, you should re-run vmake
to generate a new makefile.
The vmake utility ignores library objects compiled with -nodebug.
This command provides additional information with the -help switch.

Syntax
vmake [-cygdrive] [-du <design_unit_name> ...] [-f <filename>] [-fullsrcpath] [-ignore]
[<library_name>] [-modelsimini <ini_filepath>]
Arguments
• -cygdrive
Generates a makefile that uses a path specified with UNIX pathname conventions. Use this
argument if you are using cygwin v3.81 or later (which no longer supports Windows
conventions for drive and pathname). Optional.
• -du <design_unit_name>
Specifies that a vmake file will be generated only for the specified design unit. You can
specify this argument any number of times for a single vmake command. Optional.
• -f <filename>
Specifies a file to read command line arguments from. Optional.
Refer to the section "Argument Files" for more information

ModelSim Reference Manual, v10.1c 347

Commands
vmake

• -fullsrcpath
Produces complete source file paths within generated makefiles. By default, source file
paths are relative to the directory in which compilations originally occurred. Use this
argument to copy and evaluate generated makefiles within directories that are different from
where compilations originally occurred. Optional.
• -ignore
Omits a make rule for the named primary design unit and its secondary design units.
Optional.
• <library_name>
Specifies the library name; if none is specified, then work is assumed. Optional.
• -modelsimini <ini_filepath>
Loads an alternate initialization file that replaces the current initialization file. Overrides the
file path specified by the MODELSIM environment variable. Specifies either an absolute or
relative path to the initialization file. On Windows systems, the path separator should be a
forward slash (/). Optional.
Examples
• To produce a makefile for the work library:
vmake >mylib.mak

• To run vmake on libraries other than work:

vmake mylib >mylib.mak

• To rebuild mylib, specify its makefile when you run MAKE:

make -f mylib.mak

• To use vmake and MAKE on your work library:

C:\MIXEDHDL> vmake >makefile

• To edit an HDL source file within the work library:

C:\MIXEDHDL> make

Your design gets recompiled for you. You can change the design again and re-run
MAKE to recompile additional changes.
• To run vmake on libraries other than work:
C:\MIXEDHDL> vmake mylib >mylib.mak

• To rebuild mylib, specify its makefile when you run MAKE:

C:\MIXEDHDL> make -f mylib.mak

348 ModelSim Reference Manual, v10.1c

Commands
vmap

vmap
The vmap command defines a mapping between a logical library name and a directory by
modifying the modelsim.ini file.
With no arguments, vmap reads the appropriate modelsim.ini file(s) and prints to the transcript
the current logical library to physical directory mappings.
This command provides additional information with the -help switch.

Syntax
vmap [-c | -del <logical_name> ... | <logical_name> [<path>] ]
[-modelsimini <path/modelsim.ini>]
Arguments
• -c
(optional) Copies the default modelsim.ini file from the ModelSim installation directory to
the current directory.
This argument is intended only for making a copy of the default modelsim.ini file to the
current directory. Do not use it while making your library mappings or the mappings may
end up in the incorrect copy of the modelsim.ini.
• -del <logical_name> ...
(optional) Deletes the mapping specified by <logical_name> from the current project file.
You can specify multiple logical name arguments to the -del switch to delete multiple
library mappings.
• <logical_name> [<path>]
(optional) Maps a logical library name to the specified physical library.
If you do not specify <path> the command returns the current mapping for <logical_name>.
• -modelsimini <path/modelsim.ini>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable. Specifies either
an absolute or relative path to the initialization file. On Windows systems the path separator
should be a forward slash (/).
Examples
• Map two logical libraries to the physical library “work”, then delete the two logical
libraries:
vlib work
vmap library1 work
vmap library2 work

• Display information about the logical library “library1”:

ModelSim Reference Manual, v10.1c 349

Commands
vmap

vmap library1

• Delete the logical library mappings:

vmap -del library1 library2

350 ModelSim Reference Manual, v10.1c

Commands
vsim

vsim
The vsim command invokes the VSIM simulator, which you can use to view the results of a
Commands

previous simulation run (when invoked with the -view switch), or to view coverage data stored
in the UCDB from a previous simulation run (when invoked with the -viewcov switch).
You can simulate a VHDL configuration or an entity/architecture pair, a Verilog module or
configuration. If you specify a VHDL configuration, it is invalid to specify an architecture.
During elaboration vsim determines if the source has been modified since the last compile.
You can use this command in batch mode from the Windows command prompt. Refer to “Batch
Mode” for more information on the VSIM batch mode.
To manually interrupt design loading, use the Break key or <Ctrl-C> from a shell.
You can invoke vsim from a command prompt or in the Transcript window of the Main
window. You can also invoke it from the GUI by selecting Simulate > Start Simulation.
All arguments to the vsim command are case sensitive; for example, -g and -G are not
equivalent.
Syntax
Note
This Syntax section presents all of the vsim switches in alphabetical order, while the
Arguments section groups the arguments into the following sections:

Arguments, all languages

Arguments, VHDL
Arguments, Verilog
Arguments, object

vsim [options]
[options]:
[-absentisempty] [+alt_path_delays] [-assertfile <filename>]
[+bitblast[=[iopath | tcheck]]]
[-c] [-capacity][-classdebug] [-colormap new]
[-debugdb=<db_pathname>] [-defaultstdlogicinittoz] [+delayed_timing_checks]
[-display <display_spec>] [-displaymsgmode both | tran | wlf]
[-do “<command_string>” | <macro_file_name>] [-donotcollapsepartiallydriven]
[-dpiforceheader]
[-dpiforceheader] [-dpiheader] [-dpilib <libname>] [-dpioutoftheblue 0 | 1 | 2]
[+dumpports+collapse | +dumpports+nocollapse] [+dumpports+direction]
[+dumpports+no_strength_range] [+dumpports+unique]
[-error <msg_number>[,<msg_number>,…]]
[-enumfirstinit]
[-errorfile <filename>]

ModelSim Reference Manual, v10.1c 351

Commands
vsim

[-f <filename>] [-fatal <msg_number>[,<msg_number>,…]]

[-g <Name>=<Value> …] [-G<Name>=<Value> …] [-gblso <filename>]
[-geometry <geometry_spec>] [-gui]
[-hazards] [-help]
[-i]
[+initregNBA] [-installcolormap]
[-keeploaded] [-keeploadedrestart] [-keepstdout]
[-l <filename>] [-L <library_name> …] [-lib <libname>]
[<library_name>.<design_unit>] [-Lf <library_name> …]
[+maxdelays] [+mindelays]
[-modelsimini <ini_filepath>]
[-msglimit <msg_number>[,<msg_number>,…]] [-msgmode both | tran | wlf]
[-multisource_delay min | max | latest] [+multisource_int_delays]
[-name <name>] [+no_autodtc] [-noautoldlibpath] [-nodpiexports]
[+no_cancelled_e_msg] [+no_glitch_msg] [+no_neg_tchk] [+no_notifier]
[+no_path_edge] [+no_pulse_msg] [-no_risefall_delaynets]
[+no_show_cancelled_e] [+no_tchk_msg] [-nocollapse] [-nocapacity] [-nocompress]
[-noexcludehiz] [-noexcludeternary] [-nofileshare]
[-noimmedca] [-noglitch] [-noschematic]
[+nosdferror] [+nosdfwarn] [+nospecify] [-nostdout]
[-note <msg_number>[,<msg_number>,…]]
[+notimingchecks | +ntcnotchks] [-novhdlvariablelogging] [+nowarnBSOB]
[+nowarn<CODE | number>] [-nowiremodelforce] [+ntc_warn] [+ntcnotchks]
[-oldvhdlforgennames] [-onfinish ask | stop | exit | final]
[-pduignore[=<instpath>]] [-permissive] [-pli "<object list>"]
[-plicompatdefault [latest | 2005 | 2001]] [+<plusarg>] [-printsimstats]
[+pulse_e/<percent>] [+pulse_e_style_ondetect] [+pulse_e_style_onevent]
[+pulse_r/<percent>]
[-quiet]
[-runinit]
[+sdf_iopath_to_prim_ok]
[+sdf_nocheck_celltype]
[-sdfmin | -sdftyp | -sdfmax[@<delayScale>] [<instance>=]<sdf_filename>]
[-sdfminr | -sdftypr | -sdfmaxr[@<delayScale>] [<instance>=]<sdf_filename>]
[-sdfmaxerrors <n>] [-sdfnoerror] [-sdfnowarn] [+sdf_report_unannotated_insts]
[+sdf_verbose] [-std_input <filename>] [-std_output <filename>]
[+show_cancelled_e]
[-strictvital] [-suppress <msg_number>[,<msg_number>,…]] [-sv_lib <shared_obj>]
[-sv_liblist <filename>] [-sv_root <dirname>]
[-sync]
[-t [<multiplier>]<time_unit>] [-tab <tabfile>] [-tag <string>] [-title <title>]
[-trace_foreign <int>] [+transport_int_delays]
[+transport_path_delays] [+typdelays]

352 ModelSim Reference Manual, v10.1c

Commands
vsim

[-usenonstdcoveragesavesysf]
[-uvmcontrol={<args>}]
[-v2k_int_delays][-vcdstim [<instance>=]<filename>]
[-version] [-vhdlvariablelogging] [-view [<alias_name>=]<WLF_filename>]
[-viewcov [<dataset_name>=]<UCDB_filename>] [-visual <visual>] [-vital2.2b]
[-warning <msg_number>[,<msg_number>,…]] [-wlf <file_name>]
[-wlfcachesize <n>] [-wlfcollapsedelta] [-wlfcollapsetime] [-nowlfcollapse]
[-wlfcompress] [-nowlfcompress] [-wlfdeleteonquit] [-nowlfdeleteonquit]
[-wlflock] [-nowlflock] [-wlfopt] [-nowlfopt] [-wlfsimcachesize <n>] [-wlfslim
<size>]
[-wlftlim <duration>]
Arguments, all languages
• -assertfile <filename>
(optional) Designates an alternative file for recording VHDL assertion messages. An
alternate file may also be specified by the AssertFile modelsim.ini variable. By default,
assertion messages are output to the file specified by the TranscriptFile variable in the
modelsim.ini file. Refer to “Creating a Transcript File” for more information.
• +bitblast[=[iopath | tcheck]]
(optional) Enables bit-blasting of specify block iopaths and timing checks (tchecks) with
wide atomic ports. Without the optional qualifiers, the switch operates on both specify paths
and tchecks. The qualifiers work as follows:
+bitblast=iopath — bit-blasts only specify paths with wide ports.
+bitblast=tcheck — bit-blasts only tchecks with wide ports.
This switch is intended for use with applications employing SDF annotation.
• -c
(optional) Specifies that the simulator is to be run in command-line mode. Refer to “Modes
of Operation” for more information.
• -capacity
(optional) Enables the fine-grain analysis display of memory capacity where the default is
coarse-grain analysis display.
• -colormap new
(optional) Specifies that the window should have a new private colormap instead of using
the default colormap for the screen.
• -debugdb=<db_pathname>
(optional) Instructs ModelSim to generate a database of connectivity information to be used
for post-sim debug in the Dataflow and Schematic windows. The database pathname should
have a .dbg extension. If a database pathname is not specified, ModelSim creates a database
file named vsim.dbg in the current directory.

ModelSim Reference Manual, v10.1c 353

Commands
vsim

An existing .dbg file will be reused and a note printed to the transcript when the -debugdb
switch is specified and your design has not changed since the database was created.
Refer to “Post-Simulation Debug Flow Details” for more information.
• -defaultstdlogicinittoz
(optional) Sets the default VHDL initialization of std_logic to "Z" (high impedance) for
ports of type OUT and INOUT. IEEE Std 1076-1987 VHDL Language Reference Manual
(LRM) compliant behavior is for std_logic to initialize to "U" (uninitialized) which is
incompatible with the behavior expected by synthesis and hardware.
• -display <display_spec>
(optional) Specifies the name of the display to use. Does not apply to Windows platforms.
For example:
-display :0

• -displaymsgmode both | tran | wlf

(optional) Controls the transcription of $display system task messages to the transcript
and/or the Message Viewer. Refer to the section "Message Viewer Window" in the User’s
Manual for more information and the displaymsgmode .ini file variable.
both — outputs messages to both the transcript and the WLF file.
tran — outputs messages only to the transcript, therefore they are not available in the
Message Viewer. Default behavior.
wlf — outputs messages only to the WLF file/Message Viewer, therefore they are not
available in the transcript.
The display system tasks displayed with this functionality include: $display, $strobe,
$monitor, $write as well as the analogous file I/O tasks that write to STDOUT, such as
$fwrite or $fdisplay.
• -do “<command_string>” | <macro_file_name>
(optional) Instructs vsim to use the command(s) specified by <command_string> or the
macro file named by <macro_file_name> rather than the startup file specified in the .ini file,
if any. Multiple commands should be separated by semi-colons (;).
• -donotcollapsepartiallydriven
(optional) Prevents the collapse of partially driven and undriven output ports during
optimization. Prevents incorrect values that can occur when collapsed.
• +dumpports+collapse | +dumpports+nocollapse
(optional) Determines whether vectors (VCD id entries) in dumpports output are collapsed
or not. The default behavior is collapsed, and can be changed by setting the
DumpportsCollapse variable in the modelsim.ini file.
• +dumpports+direction
(optional) Modifies the format of extended VCD files to contain direction information.

354 ModelSim Reference Manual, v10.1c

Commands
vsim

• +dumpports+no_strength_range
(optional) Ignores strength ranges when resolving driver values for an extended VCD file.
This argument is an extension to the IEEE 1364 specification. Refer to “Resolving Values”
for additional information.
• +dumpports+unique
(optional) Generates unique VCD variable names for ports in a VCD file even if those ports
are connected to the same collapsed net.
• -enumfirstinit
(optional) Initializes enum variables in SystemVerilog using the leftmost value as the
default. You must also use the argument with the vlog command in order to implement this
initialization behavior. Specify the EnumBaseInit variable as 0 in the modelsim.ini file to set
this as a permanent default.
• -error <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "error.” Edit the error
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
• -errorfile <filename>
(optional) Designates an alternative file for recording error messages. An alternate file may
also be specified by the ErrorFile modelsim.ini variable. By default, error messages are
output to the file specified by the TranscriptFile variable in the modelsim.ini file (refer to
“Creating a Transcript File”).
• -f <filename>
(optional) Specifies a file with more vsim command arguments. Allows complex argument
strings to be reused without retyping.
Refer to the section "Argument Files" for more information.
• -fatal <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "fatal." Edit the fatal
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
• -g <Name>=<Value> …
(optional) Assigns a value to all specified VHDL generics and Verilog parameters that have
not received explicit values in generic maps, instantiations, or via defparams (such as top-
level generics/parameters and generics/parameters that would otherwise receive their
default values).
Note there is a space between -g and <Name>=<Value> however, no spaces are allowed in
the specification, unless enclosed in quotes when specifying a string value. Multiple -g
options are allowed, one for each generic/parameter, specified as a space separated list.

ModelSim Reference Manual, v10.1c 355

Commands
vsim

<Name> — Name of a generic/parameter, exactly as it appears in the VHDL source

(case is ignored) or Verilog source. Name may be prefixed with a relative or absolute
hierarchical path to select generics in an instance-specific manner. For example,
specifying -g/top/u1/tpd=20ns on the command line would affect only the tpd generic
on the /top/u1 instance, assigning it a value of 20ns. Specifying -gu1/tpd=20ns affects
the tpd generic on all instances named u1. Specifying-gtpd=20ns affects all generics
named tpd.
<Value> — Specifies an appropriate value for the declared data type of a VHDL
generic or any legal value for a Verilog parameter. Make sure the value you specify
for a VHDL generic is appropriate for VHDL declared data types. Integers are treated
as signed values. For example, -gp=-10 overwrites the parameter p with the signed
value of -10.
If more than one -g option selects a given generic the most explicit specification takes
precedence. For example,
vsim -g/top/ram/u1/tpd_hl=10ns -gtpd_hl=15ns top

This command sets tpd_hl to 10ns for the /top/ram/u1 instance. However, all other tpd_hl
generics on other instances will be set to 15ns.
Limitation: In general, generics/parameters of composite type (arrays and records) cannot
be set from the command line. However, you can set string arrays, std_logic vectors, and bit
vectors if they can be set using a quoted string. For example,
-gstrgen="This is a string"
-gslv="01001110"

The quotation marks (" ") must make it into vsim as part of the string because the type of the
value must be determinable outside of any context. Therefore, when entering this command
from a shell, put single quotes ( ‘ ‘ ) around the string. For example:
-gstrgen='"This is a string"'

If working within the ModelSim GUI, you would enter the command as follows:
{-gstrgen="This is a string"}

You can also enclose the value escaped quotes (\"), for example:
-gstrgen=\"This is a string\"

• -G<Name>=<Value> …
(optional) Same as -g (see above) except that it will also override generics/parameters that
received explicit values in generic maps, instantiations, or from defparams.
Note there is a space between -G and <Name>=<Value> however, no spaces are allowed in
the specification, unless enclosed in quotes when specifying a string value. This argument is
the only way for you to alter the generic/parameter, such as its length, (other than its value)
after the design has been loaded.
<Name> — Name of a generic/parameter, exactly as it appears in the VHDL source
(case is ignored) or Verilog source. Name may be prefixed with a relative or absolute

356 ModelSim Reference Manual, v10.1c

Commands
vsim

hierarchical path to select generics in an instance-specific manner. For example,

specifying -G/top/u1/tpd=20ns on the command line would affect only the tpd
generic on the /top/u1 instance, assigning it a value of 20ns. Specifying
-Gu1/tpd=20ns affects the tpd generic on all instances named u1. Specifying
-Gtpd=20ns affects all generics named tpd.
<Value> — Specifies an appropriate value for the declared data type of a VHDL
generic or any legal value for a Verilog parameter. Make sure the value you specify
for a VHDL generic is appropriate for VHDL declared data types. Integers are treated
as signed values. For example, -Gp=-10 overwrites the parameter p with the signed
value of -10.
• -gblso <filename>
(optional) On UNIX platforms, loads PLI/FLI shared objects with global symbol visibility.
Essentially all data and functions are exported from the specified shared object and are
available to be referenced and used by other shared objects. You can also specify this
argument with the GlobalSharedObjectsList variable in the modelsim.ini file.
• -geometry <geometry_spec>
(optional) Specifies the size and location of the main window. Where <geometry_spec> is
of the form:
WxH+X+Y

• -gui
(optional) Starts the ModelSim GUI without loading a design and redirects the standard
output (stdout) to the GUI Transcript window.
• -help
(optional) Sends the arguments and syntax for vsim to the transcript.
• -i
(optional) Specifies that the simulator be run in interactive mode.
• +initregNBA
(optional) Specifies that +initreg settings applied to registers of sequential UDPs should be
non-blocking. This is useful when continuous assignments overwrite register initialization.
• -installcolormap
(optional) For UNIX only. Causes vsim to use its own colormap so as not to hog all the
colors on the display. This is similar to the -install switch on Netscape.
• -keeploaded
(optional) Prevents the simulator from unloading/reloading any FLI/PLI/VPI shared
libraries when it restarts or loads a new design. The shared libraries will remain loaded at
their current positions. User application code in the shared libraries must reset its internal
state during a restart in order for this to work effectively.

ModelSim Reference Manual, v10.1c 357

Commands
vsim

• -keeploadedrestart
(optional) Prevents the simulator from unloading/reloading any FLI/PLI/VPI shared
libraries during a restart. The shared libraries will remain loaded at their current positions.
User application code in the shared libraries must reset its internal state during a restart in
order for this to work effectively.
We recommend using this option if you’ll be doing warm restores after a restart and the user
application code has set callbacks in the simulator. Otherwise, the callback function pointers
might not be valid if the shared library is loaded into a new position.
• -keepstdout
(optional) For use with foreign programs. Instructs the simulator to not redirect the stdout
stream to the Main window.
• -l <filename>
(optional) Saves the contents of the Transcript window to <filename>. Default is taken from
the TranscriptFile variable (initially set to transcript) in the modelsim.ini. You can also
specify “stdout” or “stderr” as <filename>.
• -L <library_name> …
(optional) Specifies the library to search for design units instantiated from Verilog and for
VHDL default component binding. Refer to “Library Usage” for more information. If
multiple libraries are specified, each must be preceded by the -L option. Libraries are
searched in the order in which they appear on the command line.
• -Lf <library_name> …
(optional) Same as -L but libraries are searched before ‘uselib directives. Refer to “Library
Usage” for more information.
• -lib <libname>
(optional) Specifies the default working library where vsim will look for the design unit(s).
Default is "work".
• -msglimit <msg_number>[,<msg_number>,…]
(optional) Limits the number of iterations of the specified message(s) to five then
suppresses all new instances. Refer to “Suppressing VSIM Warning Messages” for more
information.
<msg_number>[,<msg_number>,…] — Specifies the message number(s) to limit to
five iterations. Multiple messages are specified as a comma-separated list.
• -msgmode both | tran | wlf
(optional) Specifies the location(s) for the simulator to output elaboration and runtime
messages.
both — outputs messages to both the transcript and the WLF file.
tran — outputs messages only to the transcript, therefore they are not available in the
Message Viewer. Default behavior.

358 ModelSim Reference Manual, v10.1c

Commands
vsim

wlf — outputs messages only to the WLF file/Message Viewer , therefore they are not
available in the transcript.
Refer to the section "Message Viewer Window" in the User’s Manual for more information.
• -modelsimini <ini_filepath>
(optional) Loads an alternate initialization file that replaces the current initialization file.
Overrides the file path specified in the MODELSIM environment variable. Specifies either
an absolute or relative path to the initialization file. On Windows systems the path separator
should be a forward slash (/).
• -multisource_delay min | max | latest
(optional) Controls the handling of multiple PORT or INTERCONNECT constructs that
terminate at the same port. By default, the Module Input Port Delay (MIPD) is set to the
max value encountered in the SDF file. Alternatively, you may choose the min or latest of
the values. If you have a Verilog design and want to model multiple interconnect paths
independently, use the +multisource_int_delays argument.
• +multisource_int_delays
(optional) Enables multisource interconnect delay with pulse handling and transport delay
behavior. Works for both Verilog and VITAL cells.
Use this argument when you have interconnect data in your SDF file and you want the delay
on each interconnect path modeled independently. Pulse handling is configured using the
+pulse_int_e and +pulse_int_r switches (described below).
The +multisource_int_delays argument cannot be used if you compiled using the -novital
argument to vcom. The -novital argument instructs vcom to implement VITAL
functionality using VHDL code instead of accelerated code, and multisource interconnect
delays cannot be implemented purely within VHDL.
• -name <name>
(optional) Specifies the application name used by the interpreter for send commands. This
does not affect the title of the window.
• -noautoldlibpath
(optional) Disables the default internal setting of LD_LIBRARY_PATH, enabling you to
set it yourself. Use this argument to make sure that LD_LIBRARY_PATH is not set
automatically while you are using the GUI,
• -nocapacity
(optional) Disables the display of both coarse-grain and fine-grain analysis of memory
capacity.
• -nocompress
(optional) Causes VSIM to create uncompressed checkpoint files. This option may also be
specified with the CheckpointCompressMode variable in the modelsim.ini file.

ModelSim Reference Manual, v10.1c 359

Commands
vsim

• -noimmedca
(optional) Causes Verilog event ordering to occur without enforced prioritization—
continuous assignments and primitives are not run before other normal priority processes
scheduled in the same iteration. Use this argument to prevent the default event ordering
where continuous assignments and primitives are run with “immediate priority.” You may
also set even ordering with the ImmediateContinuousAssign variable in the modelsim.ini
file.
• +no_notifier
(optional) Disables the toggling of the notifier register argument of all timing check system
tasks. By default, the notifier is toggled when there is a timing check violation, and the
notifier usually causes a UDP to propagate an X. This argument suppresses X propagation
in both Verilog and VITAL for the entire design.
• -noschematic
(optional) Used with vsim -debugdb to generate a debug database for the Dataflow window
only. Will not remove schematic information that has already been generated by with vopt
-debugdb.
• +nospecify
(optional) Disables specify path delays and timing checks in Verilog.
• -nostdout
(optional) Directs all output to the transcript only when in command line and batch mode.
Prevents duplication of I/O between the shell and the transcript file. Has no affect on
interactive GUI mode.
• +no_tchk_msg
(optional) Disables error messages generated when timing checks are violated. For Verilog,
it disables messages issued by timing check system tasks. For VITAL, it overrides the
MsgOn arguments and generics.
Notifier registers are still toggled and may result in the propagation of Xs for timing check
violations.
• -note <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "note." Edit the note
variable in the modelsim.ini file to set a permanent default. Refer to “Changing Message
Severity Level” for more information.
• +notimingchecks | +ntcnotchks
(optional) Disables Verilog timing checks. (This option sets the generic TimingChecksOn to
FALSE for all VHDL Vital models with the Vital_level0 or Vital_level1 attribute. Generics
with the name TimingChecksOn on non-VITAL models are unaffected.) By default, Verilog
timing check system tasks ($setup, $hold,…) in specify blocks are enabled. For VITAL, the
timing check default is controlled by the ASIC or FPGA vendor, but most default to
enabled.

360 ModelSim Reference Manual, v10.1c

Commands
vsim

Additionally, +ntcnotchks maintains the delay net delays necessitated by negative timing
check limits. For this reason when using +ntcnotchks it is necessary to SDF annotate all
timing check values.
• -nowiremodelforce
(optional) Restores the force command to previous usage (prior to version 10.0b) where an
input port cannot be forced directly if it is mapped at a higher level in VHDL and mixed
models. Signals must be forced at the top of the hierarchy connected to the input port.
• -pduignore[=<instpath>]
Ignore Preoptimized Design Unit (black-box). If <instpath> is not specified all PDUs found
in compiled libraries will be ignored. Otherwise the PDU specified by <instpath> will be
ignored. This option may be specified multiple times with different <instpath>s. Equivalet
to the deprecated “-ignore_bbox” option.
• -permissive
(optional) Allows messages in the LRM group of error messages to be downgraded to a
warning.
• -plicompatdefault [latest | 2005 | 2001]
(optional) Specifies the VPI object model behavior within vsim. This switch applies
globally, not to individual libraries.
latest — This is equivalent to the "2009" argument. This is the default behavior if you do
not specify this switch or if you specify the switch without an argument.
2009 — Instructs vsim to use the object models as defined in IEEE Std P1800-2009
(unapproved draft standard). You can also use "09" as an alias.
2005 — Instructs vsim to use the object models as defined in IEEE Std 1800-2005 and
IEEE Std 1364-2005. You can also use "05" as an alias.
2001 — Instructs vsim to use the object models as defined in IEEE Std 1364-2001.
When you specify this argument, SystemVerilog objects will not be accessible. You
can also use "01" as an alias.
You can also control this behavior with the PliCompatDefault variable in the modelsim.ini
file, where the -plicompatdefault argument will override the PliCompatDefault variable.
You should note that there are a few cases where the 2005 VPI object model is incompatible
with the 2001 model, which is inherent in the specifications.
Refer to the appendix "Verilog Interfaces to C" in the User’s Manual for more information.
• -printsimstats
(optional) Prints the output of the simstats command to the transcript at the end of
simulation before exiting. Edit the PrintSimStats variable in the modelsim.ini file to set the
simulation to print the simstats data by default.

ModelSim Reference Manual, v10.1c 361

Commands
vsim

• +pulse_int_e/<percent>
(optional) Controls how pulses are propagated through interconnect delays, where
<percent> is a number between 0 and 100 that specifies the error limit as a percentage of the
interconnect delay. Used in conjunction with +multisource_int_delays (see above). This
option works for both Verilog and VITAL cells, though the destination of the interconnect
must be a Verilog cell. The source may be VITAL or Verilog.
A pulse greater than or equal to the error limit propagates to the output in transport mode
(transport mode allows multiple pending transitions on an output). A pulse less than the
error limit and greater than or equal to the rejection limit (see +pulse_int_r/<percent>
below) propagates to the output as an X. If the rejection limit is not specified, then it
defaults to the error limit. For example, consider an interconnect delay of 10 along with a
+pulse_int_e/80 option. The error limit is 80% of 10 and the rejection limit defaults to 80%
of 10. This results in the propagation of pulses greater than or equal to 8, while all other
pulses are filtered.
• +pulse_int_r/<percent>
(optional) Controls how pulses are propagated through interconnect delays, where
<percent> is a number between 0 and 100 that specifies the rejection limit as a percentage of
the interconnect delay. This option works for both Verilog and VITAL cells, though the
destination of the interconnect must be a Verilog cell. The source may be VITAL or
Verilog.
A pulse less than the rejection limit is filtered. If the error limit is not specified by
+pulse_int_e then it defaults to the rejection limit.
• -quiet
(optional) Disable 'Loading' messages during batch-mode simulation.
• -runinit
(optional) Initializes non-trivial static SystemVerilog variables, for example expressions
involving other variables and function calls, before displaying the simulation prompt.
• +sdf_iopath_to_prim_ok
(optional) Prevents vsim from issuing an error when it cannot locate specify path delays to
annotate. If you specify this argument, IOPATH statements are annotated to the primitive
driving the destination port if a corresponding specify path is not found. Refer to “SDF to
Verilog Construct Matching” for additional information.
• -sdfmin | -sdftyp | -sdfmax[@<delayScale>] [<instance>=]<sdf_filename>
(optional) Annotates VITAL or Verilog cells in the specified SDF file (a Standard Delay
Format file) with minimum, typical, or maximum timing.
@<delayScale> — scales all values by the specified value. For example, if you specify
-sdfmax@1.5, all maximum values in the SDF file are scaled to 150% of their
original value.

362 ModelSim Reference Manual, v10.1c

Commands
vsim

<instance>= — specifies a specific instance for the associated SDF file. Use this when
not performing backannotation at the top level.
<sdf_filename> — specifies the file containing the SDF information.
• -sdfminr | -sdftypr | -sdfmaxr[@<delayScale>] [<instance>=]<sdf_filename>
(optional) Specifies when an instance of a Preoptimized Design Unit (vopt -pdu, formerly
-bbox) with an associated default SDF file is to be re-annotated with minimum, typical, or
maximum timing from the specified SDF file.
@<delayScale> — scales all values by the specified value. For example, if you specify
-sdfmax@1.5, all maximum values in the SDF file are scaled to 150% of their
original value.
<instance>= — specifies a specific instance for the associated SDF file. Use this when
not performing back-annotation at the top level.
<sdf_filename> — specifies the file containing the SDF information.
Note
The simulator assumes that the instance/timing object hierarchy in the new SDF file is
compatible with the SDF file specified together with vopt -pdu (black-boxing).

The following is a simple usage flow:

Assume module top contains three instances (u1, u2, and u3) of a Preoptimized Design
Unit named pduMod.
vlib work
vlog pduMod.v

Preoptimize pduMod and annotate with sdf1.

vopt -pdu pduMod -o pduMod_opt -sdfmin pduMod=sdf1
vlog top.v

Use the default SDF file sdf1 for the PDU instance of u1, but override the SDF for u2
and u3.
vsim top +sdf_verbose -sdftypr /top/u2=sdf2 -sdfmaxr /top/u3=sdf3
run -all

• -sdfmaxerrors <n>
(optional) Controls the number of Verilog SDF missing instance messages to be generated
before terminating vsim. <n> is the maximum number of missing instance error messages to
be emitted. The default number is 5.
• -sdfnoerror
(optional) Errors issued by the SDF annotator while loading the design prevent the
simulation from continuing, whereas warnings do not. Changes SDF errors to warnings so
that the simulation can continue.

ModelSim Reference Manual, v10.1c 363

Commands
vsim

• -sdfnowarn
(optional) Disables warnings from the SDF reader. Refer to “VHDL Simulation” for an
additional discussion of SDF.
• +sdf_report_unannotated_insts
(optional) Enables error messages for any un-annotated Verilog instances with specify
blocks or VHDL instances with VITAL timing generics that are under regions of SDF
annotation.
• +sdf_verbose
(optional) Turns on the verbose mode during SDF annotation. The Transcript window
provides detailed warnings and summaries of the current annotation as well as information
including the module name, source file name and line number.
• -suppress <msg_number>[,<msg_number>,…]
(optional) Prevents the specified message(s) from displaying. You cannot suppress Fatal or
Internal messages. Edit the suppress variable in the modelsim.ini file to set a permanent
default. Refer to “Changing Message Severity Level” for more information.
• -sync
(optional) Executes all X server commands synchronously, so that errors are reported
immediately. Does not apply to Windows platforms.
• -t [<multiplier>]<time_unit>
(optional) Specifies the simulator time resolution. <time_unit> must be one of the
following:
fs, ps, ns, us, ms, sec

The default is 1ps; the optional <multiplier> may be 1, 10 or 100. Note that there is no space
between the multiplier and the unit (for example, 10fs, not 10 fs).
If you omit the -t argument, the default simulator time resolution depends on design type:
o In a VHDL design—the value specified for the Resolution variable in modelsim.ini
is used.
o In a Verilog design with ‘timescale directives—the minimum specified time
precision of all directives is used.
o In a Verilog design with no ‘timescale directives—the value specified for the
Resolution variable in the modelsim.ini file is used.
o In a mixed design with VHDL on top—the value specified for the Resolution
variable in the modelsim.ini file is used.
o In a mixed design with Verilog on top—
• for Verilog modules not under a VHDL instance: the minimum value specified
for their ‘timescale directives is used.

364 ModelSim Reference Manual, v10.1c

Commands
vsim

• for Verilog modules under a VHDL instance: all their ‘timescale directives are
ignored (the minimum value for ‘timescale directives in all modules not under a
VHDL instance is used).
If there are no ‘timescale directives in the design, the value specified for the
Resolution variable in modelsim.ini is used.

Tip: After you have started a simulation, you can view the current simulator resolution by
using the report command as follows:

report simulator state

• -tab <tabfile>
(optional) Specifies the location of a Synopsys VCS “tab” file (.tab), which the simulator
uses to automate the registration of PLI functions in the design.
<tabfile> — The location of a .tab file contains information about PLI functions. The
tool expects the .tab file to be based on Synopsys VCS version 7.2 syntax. Because
the format for this file is non-standard, changes to the format are outside of the
control of Mentor Graphics.
• -tag <string>
(optional) Specifies a string tag to append to foreign trace filenames. Used with the
-trace_foreign <int> option. Used when running multiple traces in the same directory.
• -title <title>
(optional) Specifies the title to appear for the ModelSim Main window. If omitted the
current ModelSim version is the window title. Useful when running multiple simultaneous
simulations. Text strings with spaces must be in quotes (e.g., "my title").
• -trace_foreign <int>
(optional) Creates two kinds of foreign interface traces: a log of what functions were called,
with the value of the arguments, and the results returned; and a set of C-language files to
replay what the foreign interface side did.
The purpose of the logfile is to aid the debugging of your PLI/VPI code. The primary
purpose of the replay facility is to send the replay file to MTI support for debugging co-
simulation problems, or debugging problems for which it is impractical to send the PLI/VPI
code.
• -usenonstdcoveragesavesysf
(optional) Replaces implementation of the built-in, IEEE 1800 compliant system function
with the non-standard variant, and thus affects all calls to $coverage_save(). The action of
this switch is global.

ModelSim Reference Manual, v10.1c 365

Commands
vsim

• -uvmcontrol={<args>}
(optional) Controls UVM-Aware debug features. These features work with either a standard
Accelera-released open source toolkit or the pre-compiled UVM library package in
ModelSim.
{<args>}
You must specify at least one argument. You can enable or disable some arguments by
prefixing the argument with a dash (-). Refer to the argument descriptions for more
information.
all — Enables all UVM-Aware functionality and debug options except disable and
verbose. You must specify verbose separately.
certe — Enables the integration of the elaborated design in the Certe tool. Disables Certe
features when specified as -certe.
disable — Prevents the UVM-Aware debug package from being loaded. Changes the
results of randomized values in the simulator.
msglog — Enables messages logged in UVM to be integrated into the Message Viewer.
You must also enable wlf message logging by specifying tran or wlf with vsim -
msgmode. Disables message logging when specified as -msglog
none — Turns off all UVM-Aware debug features. Useful when multiple -uvmcontrol
options are specified in a separate script, makefile or alias and you want to be sure all
UVM debug features are turned off.
struct — (default) Enables UVM component instances to appear in the Structure
window. UVM instances appear under “uvm_root” in the Structure window. Disables
Structure window support when specified as -struct.
trlog — Enables or disables UVM transaction logging. Logs UVM transactions for
viewing in the Wave window. Disables transaction logging when specified as -trlog.
verbose — Sends UVM debug package information to the transcript. Does not affect
functionality. Must be specified separately.
Arguments may be specified as multiple instances of -uvmcontrol. Multiple arguments are
specified as a comma separated list without spaces. For example,
vsim -uvmcontrol=all,-trlog

enables all UVM features except UVM transaction logging. Where arguments are in
conflict, the last argument will override earlier arguments and a warning is issued.
You can also control UVM-Aware debugging with the UVMControl modelsim.ini variable.
• -vcdstim [<instance>=]<filename>
(optional) Specifies a VCD file from which to re-simulate the design. The VCD file must
have been created in a previous ModelSim simulation using the vcd dumpports command.
Refer to “Using Extended VCD as Stimulus” for more information.

366 ModelSim Reference Manual, v10.1c

Commands
vsim

• -version
(optional) Returns the version of the simulator as used by the licensing tools.
• -view [<alias_name>=]<WLF_filename>
(optional) Specifies a wave log format (WLF) file for vsim to read. Allows you to use vsim
to view the results from an open simulation (vsim.wlf) or an earlier saved simulation. The
Structure, Objects, Wave, and List windows can be opened to look at the results stored in
the WLF file (other ModelSim windows will not show any information when you are
viewing a dataset).
<alias_name> — Specifies an alias for <WLF_file_name> where the default is to use
the prefix of the WLF_filename. Wildcard characters are allowed.
<WLF_file_name> — Specifies the pathname of a saved WLF file.
See additional discussion in the Examples.
• -viewcov [<dataset_name>=]<UCDB_filename>
(required for coverage view mode) Invokes vsim in the coverage view mode to display
UCDB data.
• -visual <visual>
(optional) Specifies the visual to use for the window. Does not apply to Windows platforms.
Where <visual> may be:
<class> <depth> — One of the following:
{directcolor | grayscale | greyscale | pseudocolor | staticcolor | staticgray | staticgrey |
truecolor}
followed by:
<depth> — Specifies how many bits per pixel are needed for the visual.
default — Instructs the tool to use the default visual for the screen
<number> — Specifies a visual X identifier.
best <depth> — Instructs the tool to choose the best possible visual for the specified
<depth>, where:
<depth> — Specifies how many bits per pixel are needed for the visual.
• -warning <msg_number>[,<msg_number>,…]
(optional) Changes the severity level of the specified message(s) to "warning." Edit the
warning variable in the modelsim.ini file to set a permanent default. Refer to “Changing
Message Severity Level” for more information.
• -wlf <file_name>
(optional) Specifies the name of the wave log format (WLF) file to create. The default file
name is vsim.wlf. This option may also be specified with the WLFFilename variable in the
modelsim.ini file.

ModelSim Reference Manual, v10.1c 367

Commands
vsim

• -wlfcachesize <n>
(optional) Specifies the size in megabytes of the WLF reader cache. By default the cache
size is set to zero. WLF reader caching caches blocks of the WLF file to reduce redundant
file I/O. This should have significant benefit in slow network environments. This option
may also be specified with the WLFCacheSize variable in the modelsim.ini file.
• -wlfcollapsedelta
(default) Instructs ModelSim to record values in the WLF file only at the end of each
simulator delta step. Any sub-delta values are ignored. May dramatically reduce WLF file
size. This option may also be specified with the WLFCollapseMode variable in the
modelsim.ini file.
• -wlfcollapsetime
(optional) Instructs ModelSim to record values in the WLF file only at the end of each
simulator time step. Any delta or sub-delta values are ignored. May dramatically reduce
WLF file size. This option may also be specified with the WLFCollapseMode variable in
the modelsim.ini file.
• -nowlfcollapse
(optional) Instructs ModelSim to preserve all events for each logged signal and their event
order to the WLF file. May result in relatively larger WLF files. This option may also be
specified with the WLFCollapseMode variable in the modelsim.ini file.
• -wlfcompress
(default) Creates compressed WLF files. Use -wlfnocompress to turn off compression. This
option may also be specified with the WLFCompress variable in the modelsim.ini file.
• -nowlfcompress
(optional) Causes vsim to create uncompressed WLF files. WLF files are compressed by
default in order to reduce file size. This may slow simulation speed by one to two percent.
You may want to disable compression to speed up simulation or if you are experiencing
problems with faulty data in the resulting WLF file. This option may also be specified with
the WLFCompress variable in the modelsim.ini file.
• -wlfdeleteonquit
(optional) Deletes the current simulation WLF file (vsim.wlf) automatically when the
simulator exits. This option may also be specified with the WLFDeleteOnQuit variable in
the modelsim.ini file.
• -nowlfdeleteonquit
(default) Preserves the current simulation WLF file (vsim.wlf) when the simulator exits.
This option may also be specified with the WLFDeleteOnQuit variable in the modelsim.ini
file.
• -wlflock
(optional) Locks a WLF file. An invocation of ModelSim will not overwrite a WLF file that
is being written by a different invocation.

368 ModelSim Reference Manual, v10.1c

Commands
vsim

• -nowlflock
(optional) Disables WLF file locking. This will prevent vsim from checking whether a WLF
file is locked prior to opening it as well as preventing vsim from attempting to lock a WLF
once it has been opened.
• -wlfopt
(default, optional) Optimizes the WLF file. Enables faster display of waveforms in the
Wave window when the display is zoomed out to display a larger time range. This option
may also be specified with the WLFOptimize variable in the modelsim.ini file.
• -nowlfopt
(optional) Disables optimization of waveform display in the Wave window. This option
may also be specified with the WLFOptimize variable in the modelsim.ini file.
• -wlfsimcachesize <n>
(optional) Specifies the size in megabytes of the WLF reader cache for the current
simulation dataset only. By default the cache size is set to zero. This makes it easier to set
different sizes for the WLF reader cache used during simulation and those used during
postsimulation debug. WLF reader caching caches blocks of the WLF file to reduce
redundant file I/O. If neither the -wlfsimcachesize switch nor the WLFSimCacheSize
modelsim.ini variable are specified, the -wlfcachesize switch or the WLFCacheSize
modelsim.ini variable settings will be used.
• -wlfslim <size>
(optional) Specifies a size restriction for the event portion of the WLF file.
size — an integer, in megabytes, where the default is 0, which implies an unlimited size.
Note
Note that a WLF file contains event, header, and symbol portions. The size restriction is
placed on the event portion only. Consequently, the resulting file will be larger than the
specified size.

If used in conjunction with -wlftlim, the more restrictive of the limits takes precedence.
This option may also be specified with the WLFSizeLimit variable in the modelsim.ini file.
(See Limiting the WLF File Size.)
• -wlftlim <duration>
(optional) Specifies the duration of simulation time for WLF file recording. The default is
infinite time (0). The <duration> is an integer of simulation time at the current resolution;
you can optionally specify the resolution if you place curly braces around the specification.
For example,
{5000 ns}

sets the duration at 5000 nanoseconds regardless of the current simulator resolution.

ModelSim Reference Manual, v10.1c 369

Commands
vsim

The time range begins at the current simulation time and moves back in simulation time for
the specified duration. For example,
vsim -wlftlim 5000

writes at most the last 5000ns of the current simulation to the WLF file (the current
simulation resolution in this case is ns).
If used in conjunction with -wlfslim, the more restrictive of the limits will take effect.
This option may also be specified with the WLFTimeLimit variable in the modelsim.ini file.
The -wlfslim and -wlftlim switches were designed to help users limit WLF file sizes for
long or heavily logged simulations. When small values are used for these switches, the
values may be overridden by the internal granularity limits of the WLF file format. (See
Limiting the WLF File Size.)
Arguments, VHDL
• -absentisempty
(optional) Causes VHDL files opened for read that target non-existent files to be treated as
empty, rather than ModelSim issuing fatal error messages.
• -nocollapse
(optional) Disables the optimization of internal port map connections.
• -nofileshare
(optional) Turns off file descriptor sharing. By default ModelSim shares a file descriptor for
all VHDL files opened for write or append that have identical names.
• -noglitch
(optional) Disables VITAL glitch generation.
Refer to “VHDL Simulation” for additional discussion of VITAL.
• +no_glitch_msg
(optional) Disable VITAL glitch error messages.
• -novhdlvariablelogging
(optional) This switch turns off the ability to log recursively or add process variables to the
Wave or List windows. Refer to -vhdlvariable logging and VhdlVariableLogging
modelsim.ini variable for more information.
• -std_input <filename>
(optional) Specifies the file to use for the VHDL TextIO STD_INPUT file.
• -std_output <filename>
(optional) Specifies the file to use for the VHDL TextIO STD_OUTPUT file.

370 ModelSim Reference Manual, v10.1c

Commands
vsim

• -strictvital
(optional) Specifies to exactly match the VITAL package ordering for messages and delta
cycles. Useful for eliminating delta cycle differences caused by optimizations not addressed
in the VITAL LRM. Using this argument negatively impacts simulator performance.
• -togglemaxintvalues <int>
(optional) Specifies the maximum number of VHDL integer values to record for toggle
coverage. This limit variable may be changed on a per-signal basis. The default value of
<int> is 100 values.
• +transport_int_delays
(optional) Selects transport mode with pulse control for single-source nets (one interconnect
path). By default interconnect delays operate in inertial mode (pulses smaller than the delay
are filtered). In transport mode, narrow pulses are propagated through interconnect delays.
This option works for both Verilog and VITAL cells, though the destination of the
interconnect must be a Verilog cell. The source may be VITAL or Verilog. This option
works independently from +multisource_int_delays.
• +transport_path_delays
(optional) Selects transport mode for path delays. By default, path delays operate in inertial
mode (pulses smaller than the delay are filtered). In transport mode, narrow pulses are
propagated through path delays. Note that this option affects path delays only, and not
primitives. Primitives always operate in inertial delay mode.
• +typdelays
(default) Selects the typical value in min:typ:max expressions. Has no effect if you specified
the min:typ:max selection at compile time.
If you specify the +mindelays, +typdelays, or +maxdelays flag with vopt, and specify a
different flag with vsim, the simulation will be able to use the delay value based upon the
flag specified with vopt. You must specify vsim -novopt to force the simulator to use the
delay flag specified with vsim.
• -vhdlvariablelogging
(optional) This switch makes it possible for process variables to be logged recursively or
added to the Wave and List windows (process variables can still be logged or added to the
Wave and List windows explicitly with or without this switch). For example with this vsim
switch, log -r /* will log process variables as long as vopt is specified with +acc=v and the
variables are not filtered out by the WildcardFilter (via the "Variable" entry). You can
disable this argument with -novhdlvariablelogging. Refer to-vhdlvariable logging and
VhdlVariableLogging modelsim.ini variable for more information.

ModelSim Reference Manual, v10.1c 371

Commands
vsim

Note
Logging process variables is inherently expensive on simulation performance because of
their nature. It is recommended that they not be logged, or added to the Wave and List
windows. However, if debugging requires them to be logged, then use of this switch will
lessen the performance hit in doing so.

• -vital2.2b
(optional) Selects SDF mapping for VITAL 2.2b (default is VITAL 2000).
Arguments, Verilog
• +alt_path_delays
(optional) Configures path delays to operate in inertial mode by default. In inertial mode, a
pending output transition is cancelled when a new output transition is scheduled. The result
is that an output may have no more than one pending transition at a time, and that pulses
narrower than the delay are filtered. The delay is selected based on the transition from the
cancelled pending value of the net to the new pending value. The +alt_path_delays option
modifies the inertial mode such that a delay is based on a transition from the current output
value rather than the cancelled pending value of the net. This option has no effect in
transport mode (see +pulse_e/<percent> and
+pulse_r/<percent>).
• -classdebug
(optional) Enables visibility into class instances for class and UVM debugging. You can
also enable visibility into class instances by setting the ClassDebug modelsim.ini variable to
1. Refer to the classinfo command for more information.
• +delayed_timing_checks
(optional) Causes timing checks to be performed on the delayed versions of input ports
(used when there are negative timing check limits). By default, ModelSim automatically
detects and applies +delayed_timing_checks to cells with negative timing checks. To turn
off this feature, specify +no_autodtc with vsim.
• -dpiforceheader
(optional) Forces the generation of a DPI header file even if it will be empty of function
prototypes.
• -dpiheader
(optional) Generates a header file that may then be included in C source code for DPI import
functions. Simulation quits after header file is generated. Refer to “DPI Use Flow” for
additional information.
• -dpilib <libname>
(optional) Specifies the design library name that contains DPI exports and automatically
compiled object files. If the -dpilib switch is not set, vsim loads export symbols from all

372 ModelSim Reference Manual, v10.1c

Commands
vsim

libraries accessible via vsim options -L, -Lf, and -lib. Multiple occurences of -dpilib are
supported.
• -dpioutoftheblue 0 | 1 | 2
(optional) Instructs vsim to allow DPI out-of-the-blue calls from C functions. The C
functions must not be declared as import tasks or functions.
0 — Support for DPI out-of-the-blue calls is disabled.
1 — Support for DPI out-of-the-blue calls is enabled, but debugging support is not
available.
2 — Support for DPI out-of-the-blue calls is enabled with debugging support for a
SystemC thread.
Debugging support for DPI out-of-the-blue calls from a SystemC method requires two vsim
arguments entered together at the command line: -dpioutoftheblue 2 and -scdpidebug.
Refer to -scdpidebug for more information.
• -hazards
(optional) Enables event order hazard checking in Verilog modules (Verilog only). You
must also specify this argument when you compile your design with vlog. Refer to “Hazard
Detection” for more details.
Note
Using -hazards implicitly enables the -compat argument. As a result, using this argument
may affect your simulation results.

• +maxdelays
(optional) Selects the maximum value in min:typ:max expressions. The default is the typical
value. Has no effect if you specified the min:typ:max selection at compile time.
If you specify the +mindelays, +typdelays, or +maxdelays flag with vopt, and specify a
different flag with vsim, the simulation will be able to use the delay value based upon the
flag specified with vopt. You must specify vsim -novopt to force the simulator to use the
delay flag specified with vsim.
• +mindelays
(optional) Selects the minimum value in min:typ:max expressions. The default is the typical
value. Has no effect if you specified the min:typ:max selection at compile time.
If you specify the +mindelays, +typdelays, or +maxdelays flag with vopt, and specify a
different flag with vsim, the simulation will be able to use the delay value based upon the
flag specified with vopt. You must specify vsim -novopt to force the simulator to use the
delay flag specified with vsim.
• +no_autodtc
(optional) Turns off auto-detection of optimized cells with negative timing checks and auto-
application of +delayed_timing_checks to those cells.

ModelSim Reference Manual, v10.1c 373

Commands
vsim

• +no_cancelled_e_msg
(optional) Disables negative pulse warning messages. By default vsim issues a warning and
then filters negative pulses on specify path delays. You can drive an X for a negative pulse
using +show_cancelled_e.
• +no_neg_tchk
(optional) Disables negative timing check limits by setting them to zero. By default negative
timing check limits are enabled. This is just the opposite of Verilog-XL, where negative
timing check limits are disabled by default, and they are enabled with the +neg_tchk option.
• +no_notifier
(optional) Disables the toggling of the notifier register argument of all timing check system
tasks. By default, the notifier is toggled when there is a timing check violation, and the
notifier usually causes a UDP to propagate an X. This argument suppresses X propagation
on timing violations for the entire design.
• +no_path_edge
(optional) Causes ModelSim to ignore the input edge specified in a path delay. The result of
this argument is that all edges on the input are considered when selecting the output delay.
Verilog-XL always ignores the input edges on path delays.
• +no_pulse_msg
(optional) Disables the warning message for specify path pulse errors. A path pulse error
occurs when a pulse propagated through a path delay falls between the pulse rejection limit
and pulse error limit set with the +pulse_r and +pulse_e options. A path pulse error results
in a warning message, and the pulse is propagated as an X. The +no_pulse_msg option
disables the warning message, but the X is still propagated.
• -no_risefall_delaynets
(optional) Disables the rise/fall delay net delay negative timing check algorithm. This
argument is provided to return ModelSim to its pre-6.0 behavior where violation regions
must overlap in order to find a delay net solution. In 6.0 versions and later, ModelSim uses
separate rise/fall delays, so violation regions need not overlap for a delay solution to be
found.
• +no_show_cancelled_e
(optional) Filters negative pulses on specify path delays so they don’t show on the output.
Default. Use +show_cancelled_e to drive a pulse error state.
• +no_tchk_msg
(optional) Disables error messages issued by timing check system tasks when timing check
violations occur. Notifier registers are still toggled and may result in the propagation of Xs
for timing check violations.

374 ModelSim Reference Manual, v10.1c

Commands
vsim

• -nodpiexports
(optional) Instructs ModelSim to not generate C wrapper code for DPI export task and
function routines found at elaboration time. More specifically, the command does not
generate the exportwrapper.so shared object file.
For a description on when you should use this argument, refer to the section “Deprecated
Legacy DPI Flows” in the User’s Manual.
• -noexcludehiz
(optional) Instructs ModelSim to include truth table rows that contain Hi-Z states in the
coverage count. Without this argument, these rows are automatically excluded.
• -noexcludeternary
(optional) Disables the automatic exclusion of UDB coverage data rows resulting from
ternary expressions for the entire design. Normal operation for code coverage is to include
rows corresponding to the case where two data inputs are the same, and the select input is a
“don’t care”. To disable this automatic exclusion for a specified design unit only, use “vlog
-noexcludeternary <design_unit>” instead.
• +nosdferror
(optional) Errors issued by the SDF annotator while loading the design prevent the
simulation from continuing, whereas warnings do not. Changes SDF errors to warnings so
that the simulation can continue.
• +nosdfwarn
(optional) Disables warnings from the SDF annotator.
• +nospecify
(optional) Disables specify path delays and timing checks.
• +nowarnBSOB
(optional) Disables run-time warning messages for bit-selects in initial blocks that are out of
bounds.
• +nowarn<CODE | number>
(optional) Disables warning messages in the category specified by a warning code or
number. Warnings that can be disabled include the code name in square brackets in the
warning message. For example:
** Warning: (vsim-3017) test.v(2): [TFMPC] - Too few port
connections. Expected <m>, found <n>.

The warning code for this example is TFMPC, and the warning number is 3017. Therefore,
this warning message can be disabled with +nowarnTFMPC or +nowarn3017.
• +ntc_warn
(optional) Enables warning messages from the negative timing constraint algorithm. By
default, these warnings are disabled.

ModelSim Reference Manual, v10.1c 375

Commands
vsim

This algorithm attempts to find a set of delays for the timing check delayed net arguments
such that all negative limits can be converted to non-negative limits with respect to the
delayed nets. If there is no solution for this set of limits, then the algorithm sets one of the
negative limits to zero and recalculates the delays. This process is repeated until a solution is
found. A warning message is issued for each negative limit set to zero.
• +ntcnotchks
(optional) Instructs vsim to not simulate timing checks but still consider negative timing
check limits for the calculation of delayed input delays.
• -oldvhdlforgennames
(optional) Enables the use of a previous style of naming in VHDL for … generate statement
iteration names in the design hierarchy. The previous style is controlled by the value of the
GenerateFormat value. The default behavior is to use the current style names, which is
described in “Naming Behavior of VHDL For Generate Blocks” This argument duplicates
the function of the OldVhdlForGenNames variable in modelsim.ini and will override the
setting of that variable if it specifies the current style.
• -onfinish ask | stop | exit | final
(optional) Customizes the simulator shutdown behavior when it encounters $finish in the
design:
• ask —
o In batch mode, the simulation exits.
o In GUI mode, a dialog box pops up and asks for user confirmation on whether to
quit the simulation.
• stop — stops simulation and leaves the simulation kernal running
• exit — exits out of the simulation without a prompt
• final — executes all final blocks then exits the simulation
By default, the simulator exits in batch mode; prompts you in GUI mode. Edit the OnFinish
variable in the modelsim.ini file to set the default operation of $finish.
• -pli "<object list>"
(optional) Loads a space-separated list of PLI shared objects. The list must be quoted if it
contains more than one object. This is an alternative to specifying PLI objects in the
Veriuser entry in the modelsim.ini file, refer to modelsim.ini Variables. You can use
environment variables as part of the path.
• +<plusarg>
(optional) Arguments preceded with "+" are accessible by the Verilog PLI routine
mc_scan_plusargs().

376 ModelSim Reference Manual, v10.1c

Commands
vsim

• +pulse_e/<percent>
(optional) Controls how pulses are propagated through specify path delays, where
<percent> is a number between 0 and 100 that specifies the error limit as a percentage of the
path delay.
A pulse greater than or equal to the error limit propagates to the output in transport mode
(transport mode allows multiple pending transitions on an output). A pulse less than the
error limit and greater than or equal to the rejection limit (see +pulse_r/<percent>)
propagates to the output as an X. If the rejection limit is not specified, then it defaults to the
error limit. For example, consider a path delay of 10 along with a +pulse_e/80 option. The
error limit is 80% of 10 and the rejection limit defaults to 80% of 10. This results in the
propagation of pulses greater than or equal to 8, while all other pulses are filtered. Note that
you can force specify path delays to operate in transport mode by using the +pulse_e/0
option.
• +pulse_e_style_ondetect
(optional) Selects the "on detect" style of propagating pulse errors (see +pulse_e). A pulse
error propagates to the output as an X, and the "on detect" style is to schedule the X
immediately, as soon as it has been detected that a pulse error has occurred. "on event" style
is the default for propagating pulse errors (see +pulse_e_style_onevent).
• +pulse_e_style_onevent
(optional) Selects the "on event" style of propagating pulse errors (see +pulse_e). Default. A
pulse error propagates to the output as an X, and the "on event" style is to schedule the X to
occur at the same time and for the same duration that the pulse would have occurred if it had
propagated through normally.
• +pulse_r/<percent>
(optional) Controls how pulses are propagated through specify path delays, where
<percent> is a number between 0 and 100 that specifies the rejection limit as a percentage of
the path delay.
A pulse less than the rejection limit is suppressed from propagating to the output. If the error
limit is not specified by +pulse_e then it defaults to the rejection limit.
• +sdf_nocheck_celltype
(optional) Disables the error check a for mismatch between the CELLTYPE name in the
SDF file and the module or primitive name for the CELL instance. It is an error if the names
do not match.
• +show_cancelled_e
(optional) Drives a pulse error state (’X’) for the duration of a negative pulse on a specify
path delay. By default ModelSim filters negative pulses.
• -sv_lib <shared_obj>
(required for use with DPI import libraries) Specifies the name of the DPI shared object
with no extension. Refer to “DPI Use Flow” for additional information.

ModelSim Reference Manual, v10.1c 377

Commands
vsim

• -sv_liblist <filename>
(optional) Specifies the name of a bootstrap file containing names of DPI shared objects
(libraries) to be loaded. Refer to “DPI File Loading” for format information.
• -sv_root <dirname>
(optional) Specifies the directory name to be used as the prefix for DPI shared object
lookups.
• +transport_int_delays
(optional) Selects transport mode with pulse control for single-source nets (one interconnect
path). By default interconnect delays operate in inertial mode (pulses smaller than the delay
are filtered). In transport mode, narrow pulses are propagated through interconnect delays.
This option works for both Verilog and VITAL cells, though the destination of the
interconnect must be a Verilog cell. The source may be VITAL or Verilog. This option
works independently from +multisource_int_delays.
• +transport_path_delays
(optional) Selects transport mode for path delays. By default, path delays operate in inertial
mode (pulses smaller than the delay are filtered). In transport mode, narrow pulses are
propagated through path delays. Note that this option affects path delays only, and not
primitives. Primitives always operate in inertial delay mode.
• +typdelays
(default) Selects the typical value in min:typ:max expressions. Has no effect if you specified
the min:typ:max selection at compile time.
If you specify the +mindelays, +typdelays, or +maxdelays flag with vopt, and specify a
different flag with vsim, the simulation will be able to use the delay value based upon the
flag specified with vopt. You must specify vsim -novopt to force the simulator to use the
delay flag specified with vsim.
• -v2k_int_delays
(optional) Causes interconnect delays to be visible at the load module port per the IEEE
1364-2001 spec. By default ModelSim annotates INTERCONNECT delays in a manner
compatible with Verilog-XL. If you have $sdf_annotate() calls in your design that are not
getting executed, add the Verilog task $sdf_done() after your last $sdf_annotate() to remove
any zero-delay MIPDs that may have been created. May be used in tandem with the
+multisource_int_delays argument (see above).
Arguments, object
The object arguments may be a [<library_name>].<design_unit>, an .mpf file, a .wlf file, or
a text file. Multiple design units may be specified for Verilog modules and mixed
VHDL/Verilog configurations.
• <library_name>.<design_unit>
(optional) Specifies a library and associated design unit; multiple library/design unit
specifications can be made. If no library is specified, the work library is used. You cannot

378 ModelSim Reference Manual, v10.1c

Commands
vsim

use the wildcard * for this argument. Environment variables can be used. <design_unit>
may be one of the following:
<configuration> Specifies the VHDL configuration to simulate.
<module> … (optional) Specifies the name of one or more top-level
Verilog modules to be simulated.
<entity> [(<architecture>)] (optional) Specifies the name of the top-level VHDL entity
to be simulated. The entity may have an architecture
optionally specified; if omitted the last architecture compiled
for the specified entity is simulated. An entity is not valid if
a configuration is specified.1
1. Most UNIX shells require arguments containing () to be single-quoted to prevent special parsing by
the shell. See the examples below.

• <MPF_file_name>
(optional) Opens the specified project.
• <WLF_file_name>
(optional) Opens the specified dataset. When you open a WLF file using the following
command:
vsim test.wlf

The default behavior is to not automatically load any signals into the Wave window. You
can change this behavior, such that the Wave window contains all signals in the design, by
setting the preference PrefWave(OpenLogAutoAddWave) to 1 (true).
• <text_file_name>
(optional) Opens the specified text file in a Source window.
Examples
• Invoke vsim on the entity cpu and assigns values to the generic parameters edge and
VCC.
vsim -gedge=’"low high"’ -gVCC=4.75 cpu

If working within the ModelSim GUI, you would enter the command as follows:
vsim {-gedge="low high"} -gVCC=4.75 cpu

Instruct ModelSim to view the results of a previous simulation run stored in the WLF
file sim2.wlf. The simulation is displayed as a dataset named test. Use the -wlf option to
specify the name of the WLF file to create if you plan to create many files for later
viewing.
vsim -view test=sim2.wlf

For example:

ModelSim Reference Manual, v10.1c 379

Commands
vsim

vsim -wlf my_design.i01 my_asic structure

vsim -wlf my_design.i02 my_asic structure

Annotate instance /top/u1 using the minimum timing from the SDF file myasic.sdf.
vsim -sdfmin /top/u1=myasic.sdf

Use multiple switches to annotate multiple instances:

vsim -sdfmin /top/u1=sdf1 -sdfmin /top/u2=sdf2 top

• This example searches the libraries mylib for top(only) and gatelib for cache_set. If the
design units are not found, the search continues to the work library. Specification of the
architecture (only) is optional.
vsim ’mylib.top(only)’ gatelib.cache_set

• Invoke vsim on test_counter and run the simulation until a break event, then quit when it
encounters a $finish task.
vsim -do "set PrefMain(forceQuit) 1; run -all" work.test_counter

380 ModelSim Reference Manual, v10.1c

Commands
vsim<info>

vsim<info>
The vsim<info> commands return information about the current vsim executable.
• vsimAuth
Returns the authorization level (PE/SE, VHDL/Verilog/PLUS).
• vsimDate
Returns the date the executable was built, such as "Apr 10 2000".
• vsimId
Returns the identifying string, such as "ModelSim 6.1".
• vsimVersion
Returns the version as used by the licensing tools, such as "1999.04".
• vsimVersionString
Returns the full vsim version string.
This same information can be obtained using the -version argument of the vsim command.

ModelSim Reference Manual, v10.1c 381

Commands
vsim_break

vsim_break
Stop (interrupt) the current simulation before it runs to completion. To stop a simulation and
then resume it, use this command in conjunction with run -continue.
Syntax
vsim_break
Arguments
None.
Example
• Interrupt a simulation, then restart it from the point of interruption.
vsim_break
run -continue

382 ModelSim Reference Manual, v10.1c

Commands
vsource

vsource
This command specifies an alternative file to use for the current source file.
Commands

This command is used when the current source file has been moved. The alternative source
mapping exists for the current simulation only.
Syntax
vsource [<filename>]
Arguments
• <filename>
(optional) Specifies a relative or full pathname. If filename is omitted, the source file for the
current design context is displayed.
Examples
vsource design.vhd
vsource /old/design.vhd

ModelSim Reference Manual, v10.1c 383

Commands
wave

wave
A number of commands are available to manipulate and report on the Wave window.
The following tables summarize the available options for manipulating cursors, for zooming,
and for adjusting the wave display view in the Wave window:

Table 2-8. Wave Window Commands for Cursor

Cursor Commands Description
wave cursor active Sets the active cursor to the specified cursor or, if no cursor is
specified, reports the active cursor
wave cursor add Adds a new cursor at specified time and returns the number of
the newly added cursor
wave cursor configure Sets or reports values for the specified cursor
wave cursor delete Deletes the specified cursor or, if no cursor is specified, the
active cursor
wave cursor see Positions the wave display such that the specified or active
cursor appears at the specified percent from the left edge of the
display – 0% is the left edge, 100% is the right edge.
wave cursor time Moves or reports the time of the specified cursor or, if no
cursor is specified, the time of the active cursor

Table 2-9. Wave Window Commands for Expanded Time Display

Display view Commands Description
wave expand mode Selects the expanded time display mode: Delta Time, Event
Time, or off.
wave expand all Expands simulation time into delta time steps if Delta Time
mode is currently selected (WLFCollapseMode = 1) or into
event time steps if Event Time mode is currently selected
(WLFCollapseMode = 0) over the full range of the simulation
from time 0 to the current time.
wave expand cursor Expands simulation time into delta time steps if Delta Time
mode is currently selected (WLFCollapseMode = 1) or into
event time steps if Event Time mode is currently selected
(WLFCollapseMode = 0) at the simulation time of the active
cursor.
wave expand range Expands simulation time into delta time steps if Delta Time
mode is currently selected (WLFCollapseMode = 1) or into
event time steps if Event Time mode is currently selected
(WLFCollapseMode = 0) over a time range specified by a start
time and an end time.

384 ModelSim Reference Manual, v10.1c

Commands
wave

Table 2-9. Wave Window Commands for Expanded Time Display (cont.)
Display view Commands Description
wave collapse all Collapses simulation time over the full range of the simulation
from time 0 to the current time.
wave collapse cursor Collapses simulation time at the time of the active cursor.
wave collapse range Collapses simulation time over a specific simulation time
range.

Table 2-10. Wave Window Commands for Controlling Display

Display view Commands Description
wave interrupt Immediately stops wave window drawing
wave refresh Cleans wave display and redraws waves
wave cursor see Positions the wave display such that the specified or active
cursor appears at the specified percent from the left edge of the
display – 0% is the left edge, 100% is the right edge.
wave seetime Positions the wave display such that the specified time appears
at the specified percent from the left edge of the display – 0%
is the left edge, 100% is the right edge.

Table 2-11. Wave Window Commands for Zooming

Zooming Commands Description
wave zoom in Zoom in the wave display by the specified factor. The default
factor is 2.0.
wave zoom out Zoom out the wave display by the specified factor. The default
factor is 2.0.
wave zoom full Zoom the wave display to show the full simulation time.
wave zoom last Return to last zoom range.
wave zoom range Sets left and right edge of wave display to the specified start
time and end time. If times are not specified, reports left and
right edge times.

Syntax
wave cursor active [-window <win>] [<cursor-num>]
wave cursor add [-window <win>] [-time <time>] [-name <name>] [-lock <0 |1>]
wave cursor configure [<cursor-num>] [-window <win>] [<option> [<value>]]

ModelSim Reference Manual, v10.1c 385

Commands
wave

wave cursor delete [-window <win>] [<cursor-num>]

wave cursor see [-window <win>] [-at <percent>] [<cursor-num>]
wave cursor time [-window <win>] [-time <time>] [<cursor-num>]
wave collapse all [-window <win>]
wave collapse cursor [-window <win>] [<cursor-num>]
wave collapse range [-window <win>] <start-time> <end-time>
wave expand all [-window <win>]
wave expand cursor [-window <win>] [<cursor-num>]
wave expand mode [-window <win>] [off | deltas | events]
wave expand range [-window <win>] <start-time> <end-time>
wave interrupt [-window <win>]
wave refresh [-window <win>]
wave seetime [-window <win>] [-at <percent>] -time <time>
wave zoom in [-window <win>] [<factor>]
wave zoom out [-window <win>] [<factor>]
wave zoom full [-window <win>]
wave zoom last [-window <win>]
wave zoom range [-window <win>] [<start-time> <end-time>]
Arguments
• -at <percent>
(optional) Positions the display such that the time or cursor is the specified <percent> from
the left edge of the wave display.
<percent> — Any non-negative number where the default is 50. 0 is the left edge of the
Wave window and 100 is the right edge.
• <cursor-num>
(optional) Specifies a cursor number. If not specified, the active cursor is used.
• <factor>
(optional) A number that specifies how much you want to zoom into or out of the wave
display. Default value is 2.0.
• -lock <0 |1>
(optional) Specify the lock state of the cursor.
0 — (default) Unlocked
1 — Locked

386 ModelSim Reference Manual, v10.1c

Commands
wave

• -name <name>
(optional) Specify the name of the cursor.
<name> — Any string where the default is "Cursor <n>" where <n> is the cursor
number.
• off | deltas | events
(optional) Specifies the expanded time display mode for the Wave window. Default is off.
• <option> [<value>]
(optional) Specify a value for the designated option. Currently supported options are -name,
-time, and -lock. If no option is specified, current value of all options are reported.
• <start-time> <end-time>
(optional) start-time and end-time are times that specify an expand, collapse, or zoom range.
If neither number is specified, the command returns the current range.
• -time <time>
(optional) Specifies a cursor time.
<time> — Any positive integer.
• -window <win>
(optional) All commands default to the active Wave window unless this argument is used to
specify a different Wave window.
<win> — Specifies the name of a Wave window other than the current active window.
Examples
• Either of these commands creates a zoom range with a start time of 20 ns and an end
time of 100 ns.
wave zoom range 20ns 100ns
wave zoom range 20 100

• Return the name of cursor 2:

wave cursor configure 2 -name

• Name cursor 2, "reference cursor" and return that name with:

wave cursor configure 2 -name {reference cursor}

• Return the values of all wave cursor configure options for cursor 2:
wave cursor configure 2

ModelSim Reference Manual, v10.1c 387

Commands
wave create

wave create
This command generates a waveform known only to the GUI. You can then modify the
waveform interactively or with the wave edit command and use the results to drive simulation.
Refer to “Generating Stimulus with Waveform Editor” for more information.
Some arguments to this command are order-dependent. Please read through the argument
descriptions for more information. d
The following table summarizes the available waveform pattern options:
Command Description
wave create -pattern clock Generates a clock waveform. Recommended that you
specify an initial value, duty cycle, and clock period for
the waveform.
wave create -pattern constant Generates a waveform with a constant value. It is
suggested that you specify a value.
wave create -pattern random Generates a random waveform based upon a seed value.
Specify the type (normal or uniform), an initial value, and
a seed value. If you don't specify a seed value, Questa
uses a default value of 5.
wave create -pattern repeater Generates a waveform that repeats. Specify an initial
value and pattern that repeats. You can also specify how
many times the pattern repeats.
wave create -pattern counter Generates a waveform from a counting pattern. Specify
start and end values, repeat, step count, time period, and
type (Binary, Gray, Johnson, OneHot, Range, and
ZeroHot).
wave create -pattern none Creates a placeholder for a waveform. Specify an object
name.

Syntax
All waveforms
wave create [-driver {freeze | deposit | driver | expectedoutput}] [-initialvalue <value>]
[-language {vhdl | verilog}] [-portmode {in | out | inout | internal}] [-range <msb lsb>]
[-starttime {<time><unit>}] [-endtime {<time><unit>}] <object_name>
Clock patterns
wave create -pattern clock [-dutycycle <value>] [-period {<time><unit>}] <object_name>
Constant patterns
wave create -pattern constant [-initialvalue <value>] [-value <value>] <object_name>

388 ModelSim Reference Manual, v10.1c

Commands
wave create

Random patterns
wave create -pattern random [-initialvalue <value>] [-period {<time><unit>}]
[-random_type {normal | uniform | poisson | exponential}] [-seed <value>]
<object_name>
Repeater patterns
wave create -pattern repeater [-initialvalue <value>] [-period {<time><unit>}]
[-repeat {forever | never | <n>}] [-sequence {<val1>} <val2> …]
Counter patterns
wave create -pattern counter [-direction {up | down | upthendown | downthenup}]
[-initialvalue <value>] [-period {<time><unit>}] [-repeat {forever | never | <n>}]
[-startvalue <value>] [-endvalue <value>] [-step <value>]
[-type {binary | gray | johnson | onehot | range | zerohot}] <object_name>
No pattern
wave create -pattern none <object_name>
Arguments
• -pattern clock | constant | random | repeater | counter | none
(required) Specifies the waveform pattern. Refer to “Creating Waveforms from Patterns”
for a description of the pattern types.
clock — Specifies a clock pattern.
constant — Specifies a constant pattern.
random — Specifies a random pattern.
repeater — Specifies a repeating pattern.
counter — Specifies a counting pattern.
none — Specifies a blank pattern.
• -direction {up | down | upthendown | downthenup}
(optional, recommended when specifying -pattern counter) The direction in which the
counter will increment or decrement.
up — (default) Increment only.
down — Decrement only.
upthendown — Increment then decrement.
downthenup — Decrement then increment.
• -driver {freeze | deposit | driver | expectedoutput}
(optional) Specifies that the signal is a driver of the specified type. Applies to waveforms
created with -portmode inout or -portmode internal.

ModelSim Reference Manual, v10.1c 389

Commands
wave create

• -dutycycle <value>
(optional, recommended for -pattern clock) Specifies the duty cycle of the clock.
Expressed as a percentage of the period that the clock is high.
<value> — Any integer from 0 to 100 where the default is 50.
• -endtime {<time><unit>}
(optional) The simulation time where the waveform will stop. If omitted, the waveform
stops at 1000 simulation time units.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -endvalue <value>
(optional, recommended when specifying -pattern counter) The end value for the counter.
This option applies to patterns specifying -type Range only. All other counter patterns start
from 0 and go to the maximum value for that particular signal (for example, for a 3-bit
signal, the start value will be 000 and the end value will be 111).
<value> — Value must be appropriate for the type of waveform you are creating.
• -initialvalue <value>
(optional) The initial value for the waveform. Not applicable to counter patterns.
<value> — Value must be appropriate for the type of waveform you are creating.
• -language {vhdl | verilog}
(optional) Controls which language is used for the created wave.
vhdl — (default) Specifies the VHDL language.
verilog — Specifies the Verilog language.
• -period {<time><unit>}
(optional, recommended for all patterns except -constant) Specifies the period of the signal.
<time> — Specified as an integer or decimal number. Current simulation units are the
default unless specifying <unit>.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -portmode {in | out | inout | internal}
(optional) The port type for the waveform. Useful for creating signals prior to loading a
design.
in — Ports of type IN. You can also specify “input” as an alias for in.

390 ModelSim Reference Manual, v10.1c

Commands
wave create

out — Ports of type OUT. You can also specify “output” as an alias for out.
inout — Ports of type INOUT.
internal — (default) Ports of type INTERNAL.
• -random_type {normal | uniform | poisson | exponential}
(optional, recommended when specifying -pattern random) Specifies the type of algorithm
used to generate a random waveform pattern.
normal — Normal or Gaussian distribution of waveform events.
uniform — (default) Uniform distribution of waveform events.
poisson — Poisson distribution of waveform events.
exponential — Exponential distribution of waveform events.
• -range <msb lsb>
(optional) Identifies bit significance in a counter pattern.
msb lsb — Most significant bit and least significant bit. Both must be specified.
• -repeat {forever | never | <n>}
(optional, recommended when specifying -pattern repeater or -pattern counter) Controls
duration of pattern repetition.
forever — Repeat the pattern for as long as the simulation runs.
never — Never repeat the pattern during simulation.
<n> — Repeat the pattern <n> number of times where <n> is any positive integer.
• -seed <value>
(optional, recommended when specifying -pattern random) Specifies a seed value for a
randomly generated waveform.
<value> — Any non-negative integer where the default is 5.
• -sequence {<val1>} <val2> …
(optional, recommended when specifying pattern -repeater) The set of values that you
want repeated.
<val1> — Value must be appropriate for the type of waveform you are creating.
Multiple values are entered as a space separated list and enclosed in curly braces ({}).
• -starttime {<time><unit>}
(optional) The simulation time at which the waveform should start. If omitted, the
waveform starts at 0 simulation time units.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).

ModelSim Reference Manual, v10.1c 391

Commands
wave create

• -startvalue <value>
(required when specifying -pattern counter) The initial value of the counter. This option
applies to patterns specifying -type Range only. All other counter patterns start from 0 and
go to the maximum value for that particular signal (e.g., for a 3-bit signal, the start value
will be 000 and the end value will be 111).
<value> — Value must be appropriate for the type of waveform you are creating.
• -step <value>
(optional, recommended when specifying -pattern counter) The step by which the counter
is incremented/decremented.
<value> — Value must be appropriate for the type of waveform you are creating.
• -type {binary | gray | johnson | onehot | range | zerohot}
(optional) Specifies a counter format.
binary — Specifies a binary counter.
gray — Specifies a binary counter where two successive values differ in only one bit.
Also known as a reflected binary counter.
johnson — Specifies a twisted ring or Johnson counter.
onehot — Specifies a shift counter where only one bit at a time is set to “on” (1).
range — (default) Specifies a binary counter where the values range between
-startvalue and -endvalue
zerohot — Specifies a shift counter where only one bit at a time is set to “off” (0).
• -value <value>
(optional, recommended when specifying -pattern constant) Specifies a value for the
constant pattern.
<value> — Value must be appropriate for the type of waveform you are creating.
• <object_name>
(required) User specified name for the waveform. Must be the final argument.
Examples
• Create a clock signal with the following default values:
wave create -pattern clock -period 100 -dutycycle 50 -starttime 0 -endtime 1000
-initialvalue 0 /counter/clk

• Create a constant 8-bit signal vector from 0 to 1000 ns with a value of 1111 and a drive
type of freeze.
wave create -driver freeze -pattern constant -value 1111 -range 7 0 -starttime 0ns
-endtime 1000ns sim:/andm/v_cont2

392 ModelSim Reference Manual, v10.1c

Commands
wave create

Related Topics
• wave edit
• wave modify
• “Generating Stimulus with Waveform Editor”
• “Creating Waveforms from Patterns”

ModelSim Reference Manual, v10.1c 393

Commands
wave edit

wave edit
This command modifies waveforms created with the wave create command.
Some arguments to this command are order-dependent. Please read through the argument
descriptions for more information. d
The following table summarizes the available editing options:
Command Description
wave edit cut Cut part of a waveform to the clipboard
wave edit copy Copy part of a waveform to the clipboard
wave edit paste Paste the waveform from the clipboard
wave edit invert Vertically flip part of a waveform
wave edit mirror Mirror part of a waveform
wave edit insert_pulse Insert a new edge on a waveform; doesn’t affect waveform duration
wave edit delete Delete an edge from a waveform; doesn’t affect waveform duration
wave edit stretch Move an edge by stretching the waveform
wave edit move Move an edge without moving other edges
wave edit change_value Change the value of part of a waveform
wave edit extend Extend all waves
wave edit driveType Change the driver type
wave edit undo Undo an edit
wave edit redo Redo a previously undone edit

Syntax
wave edit {cut | copy | paste | invert | mirror} -end {<time><unit>} -start {<time><unit>}
<object_name>
wave edit insert_pulse [-duration {<time><unit>}] -start {<time><unit>} <object_name>
wave edit delete -time {<time><unit>} <object_name>
wave edit stretch | move {-backward {<time><unit>} | -forward {<time><unit>}}
-time {<time><unit>} <object_name>
wave edit change_value -end {<time><unit>} -start {<time><unit>} <value>
<object_name>
wave edit extend -extend to | by -time {<time><unit>}
wave edit driveType -driver freeze | deposit | driver | expectedoutput -end {<time><unit>}
-start {<time><unit>}
wave edit undo <number>

394 ModelSim Reference Manual, v10.1c

Commands
wave edit

wave edit redo <number>

Arguments
• -backward {<time><unit>}
(required if -forward <time> isn’t specified) The amount to stretch or move the edge
backwards in simulation time.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• cut | copy | paste | invert | mirror
(required) Specifies the type of edit to perform.
cut — Deletes the specified portion of the waveform.
copy — Saves a copy of the specified portion of the waveform.
paste — Inserts the contents of the clipboard into the specified portion of the waveform.
invert — Flips the specified portion of the waveform vertically.
mirror — Flips the specified portion of the waveform horizontally.
• -driver freeze | deposit | driver | expectedoutput
(required) Specifies the type of driver to which you want the specified section of the
waveform changed. Applies to signals of type inout or internal.
• -duration {<time><unit>}
(optional) The length of the pulse.
<time> — Specified as an integer or decimal number where the default is 10 time units.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -end {<time><unit>}
(required unless specifying paste) The end of the section of waveform to perform the editing
operation upon, denoted by a simulation time.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -extend to | by
(required) Specifies the format for extending waves.

ModelSim Reference Manual, v10.1c 395

Commands
wave edit

to — Extends the wave to the time specified by -time <time>.

by — Extends the wave by the amount of time specified by -time <time>.
• -forward {<time><unit>}
(required if -backward <time> is not specified) The amount to stretch or move the edge
forwards in simulation time.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• <number>
(optional) The number of editing operations to undo or redo. If omitted, only one editing
operation is undone or redone.
• <object_name>
(required) The pathname of the waveform to edit. Must be specified as the last argument to
wave edit.
• -start {<time><unit>}
(required) The beginning of the section of waveform to perform the editing operation upon,
denoted by a simulation time.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -time {<time><unit>}
(required) The amount of time to extend or stretch waves.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• <value>
(required) The new value. Must match the type of the <object_name>.
Related Topics
• wave create
• “Generating Stimulus with Waveform Editor”

396 ModelSim Reference Manual, v10.1c

Commands
wave export

wave export
This command creates a stimulus file from waveforms created with the wave create command.
Syntax
wave export -designunit <name> -endtime {<time><unit>} -<time> -file <name>
{-format force | vcd | vhdl | verilog} -starttime <time>
Arguments
• -designunit <name>
(required) Specifies a design unit for which you want to export created waves. If omitted,
the command exports waves from the active design unit.
<name> — Specifies a design unit in the simulation.
• -endtime {<time><unit>
(required) The simulation time at which you want to stop exporting.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -file <filename>
(required) The filename for the saved export file.
<name> — Any user specified string.
• -format force | vcd | vhdl | verilog
(required) The format of the saved stimulus file. The format options include:
force — A Tcl script that recreates the waveforms. The file should be sourced when
reloading the simulation.
vcd — An extended VCD file. Load using the -vcdstim argument to vsim.
vhdl — A VHDL test bench. Compile and load the file as your top-level design unit.
verilog — A Verilog test bench. Compile and load the file as your top-level design unit.
• -starttime {<time><unit>}
(required) The simulation time at which you want to start exporting.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).

ModelSim Reference Manual, v10.1c 397

Commands
wave export

Related Topics
• wave create
• wave import
• “Generating Stimulus with Waveform Editor”

398 ModelSim Reference Manual, v10.1c

Commands
wave import

wave import
This command imports an extended VCD file that was created with the wave export command.
It cannot read extended VCD file created by software other than ModelSim. Use this command
to apply a VCD file as stimulus to the current simulation.
Syntax
wave import <VCD_file>
Arguments
• <VCD_file>
(required) The name of the extended VCD file to import.
Related Topics
• wave create
• wave export
• “Generating Stimulus with Waveform Editor”

ModelSim Reference Manual, v10.1c 399

Commands
wave modify

wave modify
This command modifies waveform parameters set by a previous wave create command.
Some arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
The following table summarizes the available wave modification options:
Command Description
wave modify -pattern clock Generates a clock waveform. Specify an initial value,
duty cycle, and clock period for the waveform.
wave modify -pattern constant Generates a waveform with a constant value. Specify a
value.
wave modify -pattern counter Generates a waveform from a counting pattern. Specify
start and end values, repeat, step count, time period, and
type (Binary, Gray, Johnson, OneHot, Range, and
ZeroHot).
wave modify -pattern random Generates a random waveform based upon a seed value.
Specify the type (normal or uniform), an initial value, and
a seed value. If you don't specify a seed value, Questa
uses a default value of 5.
wave modify -pattern repeater Generates a waveform that repeats. Specify an initial
value and pattern that repeats. You can also specify how
many times the pattern repeats.
wave modify -pattern none Creates a placeholder for a waveform. Specify an object
name.

Syntax
All waveforms
wave modify [-driver freeze | deposit | driver | expectedoutput] [-endtime {<time><unit>}]
[-initialvalue <value>] [-portmode {in | out | inout | internal}] [-range <msb lsb>]
[-starttime {<time><unit>}] <wave_name>
Clock patterns only
wave modify -pattern clock -period <value> -dutycycle <value> <wave_name>
Constant patterns only
wave modify -pattern constant [-driver freeze | deposit | driver | expectedoutput]
[-language {vhdl | verilog}] [-value <value>] <wave_name>
Counter patterns only
wave modify -pattern counter -period <value> -repeat forever | <n> | never -startvalue
<value> -step <value> [-direction {up | down | upthendown | downthenup}]

400 ModelSim Reference Manual, v10.1c

Commands
wave modify

[-endvalue <value>] [-type {binary | gray | johnson | onehot | range | zerohot}]

<wave_name>
Random patterns only
wave modify -pattern random -period <value>
-random_type exponential | normal | poisson | uniform [-seed <value>] <wave_name>
Repeater patterns only
wave modify -pattern repeater -period <value> -repeat forever | <n> | never
-sequence {val1 val2 val3 …} <wave_name>
No pattern
wave create -pattern none <wave_name>
Arguments
• -direction {up | down | upthendown | downthenup}
(optional, recommended when specifying -pattern counter) The direction in which the
counter will increment or decrement.
up — (default) Increment only.
down — Decrement only.
upthendown — Increment then decrement.
downthenup — Decrement then increment.
• -driver freeze | deposit | driver | expectedoutput
(optional) Specifies that the signal is a driver of the specified type. Applies to signals of type
inout or internal.
• -dutycycle <value>
(required) The duty cycle of the clock, expressed as a percentage of the period that the clock
is high.
<value> — Any integer from 0 to 100 where the default is 50.
• -endtime {<time><unit>}
(optional) The simulation time that the waveform should stop. If omitted, the waveform
stops at 1000 simulation time units.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).

ModelSim Reference Manual, v10.1c 401

Commands
wave modify

• -endvalue <value>
(optional) The ending value of the counter. This option applies to Range counter patterns
only. All other counter patterns start from 0 and go to the max value for that particular signal
(for example, for a 3-bit signal, the start value will be 000 and end value will be 111).
<value> — Any positive integer.
• -initialvalue <value>
(optional) The initial value for the waveform. Value must be appropriate for the type of
waveform you are creating. Not applicable to counter patterns.
<value> — Any positive integer.
• -language {vhdl | verilog}
(optional) Controls which language is used for modifying the wave.
vhdl — (default) Specifies the VHDL language.
verilog — Specifies the Verilog language.
• -period <value>
(required) The period of the signal.
• -portmode {in | out | inout | internal}
(optional) The port type for the waveform.
in — Ports of type IN. You can also specify “input” as an alias for in.
out — Ports of type OUT. You can also specify “output” as an alias for out.
inout — Ports of type INOUT.
internal — (default) Ports of type INTERNAL.
• -random_type exponential | normal | poisson | uniform
(required) Specifies a random pattern to generate.
exponential — Exponential distribution of waveform events.
normal — Normal or Gaussian distribution of waveform events.
poisson — Poisson distribution of waveform events.
uniform — (default) Uniform distribution of waveform events.
• -range <msb lsb>
(optional) Identifies bit significance in a counter pattern.
msb lsb — Most significant bit and least significant bit. Both must be specified.
• -repeat forever | <n> | never
(required) Controls duration of pattern repetition.
forever — Repeat the pattern for as long as the simulation runs.
<n> — Repeat the pattern <n> number of times where <n> is any positive integer.

402 ModelSim Reference Manual, v10.1c

Commands
wave modify

never — Never repeat the pattern during simulation.

• -seed <value>
(optional) Specifies a seed value for a randomly generated waveform.
<value> — Any non-negative integer where the default is 5.
• -sequence {val1 val2 val3 …}
(required) The set of values that you want repeated.
<val1> — Value must be appropriate for the type of waveform you are creating.
Multiple values are entered as a space separated list and enclosed in curly braces ({}).
• -starttime {<time><unit>}
(optional) The simulation time that the waveform should start. If omitted, the waveform
starts at 0 simulation time units.
<time> — Specified as an integer or decimal number.
<unit> — (optional) A suffix specifying a unit of time where the default is to specify the
current simulation resolution by omitting <unit>. Valid time units are: fs, ps, ns, us,
ms, sec, min, and hr. If <unit> is specified, you must enclose <time> and <unit>
within curly braces ({}).
• -startvalue <value>
(required when specifying -pattern counter) The initial value of the counter. This option
applies to patterns specifying -type Range only. All other counter patterns start from 0 and
go to the maximum value for that particular signal (e.g., for a 3-bit signal, the start value
will be 000 and the end value will be 111).
<value> — Value must be appropriate for the type of waveform you are creating.
• -step <value>
(required) The step by which the counter is incremented/decremented.
<value> — Value must be appropriate for the type of waveform you are creating.
• -type {binary | gray | johnson | onehot | range | zerohot}
(optional) Specifies a counter format.
binary — Specifies a binary counter.
gray — Specifies a binary counter where two successive values differ in only one bit.
Also known as a reflected binary counter.
johnson — Specifies a twisted ring or Johnson counter.
onehot — Specifies a shift counter where only one bit at a time is set to “on” (1).
range — (default) Specifies a binary counter where the values range between
-startvalue and -endvalue
zerohot — Specifies a shift counter where only one bit at a time is set to “off” (0).

ModelSim Reference Manual, v10.1c 403

Commands
wave modify

• -value <value>
(optional, recommended when specifying -pattern constant) Specifies a value for the
constant pattern.
<value> — Value must be appropriate for the type of waveform you are creating.
• <wave_name>
(required) The name of an existing waveform created with the wave create command.
Related Topics
• wave create
• “Generating Stimulus with Waveform Editor”
• “Creating Waveforms from Patterns”.

404 ModelSim Reference Manual, v10.1c

Commands
wave sort

wave sort
This command sorts signals in the Wave window by name or full path name.
Syntax
wave sort {ascending | descending | fa | fd}
Arguments
• ascending | descending | fa | fd
(required) Sort signals in one of the following orders.
ascending — Sort in ascending order by signal name.
descending — Sort in descending order by signal name.
fa — Sort in ascending order by the full path name.
fd — Sort in descending order by full path name.
Examples
wave sort ascending

ModelSim Reference Manual, v10.1c 405

Commands
when

when
This command instructs ModelSim to perform actions when the specified conditions are met.
For example, you can use the command to break on a signal value or at a specific simulator
time. Use the nowhen command to deactivate when commands.
Syntax
when [[-fast] [-id <id#>] [-label <label>] {<when_condition_expression>} {<command>}]
Description
The when command uses a when_condition_expression to determine whether or not to
perform the action. Conditions can include VHDL signals and Verilog nets and registers. The
when_condition_expression uses a simple restricted language (that is not related to Tcl),
which permits only four operators and operands that may be either HDL object names,
signame'event, or constants. ModelSim evaluates the condition every time any object in the
condition changes, hence the restrictions.
Here are some additional points to keep in mind about the when command:
• The when command creates the equivalent of a VHDL process or a Verilog always
block. It does not work like a looping construct you might find in other languages such
as C.
• Virtual signals, functions, regions, types, and so forth, cannot be used in the when
command. Neither can simulator state variables other than $now.
• With no arguments, when will list the currently active when statements and their labels
(explicit or implicit).
Syntax
when [[-fast] [-id <id#>] [-label <label>] {<when_condition_expression>} {<command>}]
Embedded Commands Allowed with the -fast Argument
You can use any Tcl command as a <command>, along with any of the following vsim
commands:
• bp, bd
• change
• disablebp, enablebp
• echo
• examine
• force, noforce
• log, nolog
• stop

406 ModelSim Reference Manual, v10.1c

Commands
when

• when, nowhen
Embedded Commands Not Allowed with the -fast Argument
• Any do commands
• Any Tk commands or widgets
• References to U/I state variables or tcl variables
• Virtual signals, functions, or types
Using Global Tcl Variables with the -fast Argument
Embedded commands that use global Tcl variables for passing a state between the when
command and the user interface need to declare the state using the Tcl uivar command. For
example, the variable i below is visible in the GUI. From the command prompt, you can
display it (by entering echo $i) or modify it (for example, by entering set i 25).
set i 10
when -fast {clk == '0'} {
uivar i
set i [expr {$i - 1}]
if {$i <= 0} {
force reset 1 0, 0 250
}
}
when -fast {reset == '0'} {
uivar i
set i 10
}

Additional Restrictions on the -fast Argument

Accessing channels (such as files, pipes, sockets) that were opened outside of the embedded
command will not work. For example:
set fp [open mylog.txt w]
when -fast {bus} {
puts $fp "bus change: [examine bus]"
}
The channel that $fp refers to is not available in the simulator, only in the user interface.
Even using the uivar command does not work here because the value of $fp has no meaning
in the context of the -fast argument.
The following method of rewriting this example opens the channel, writes to it, then closes
it within the when command:

when -fast {bus} {

set fp [open mylog.txt a]
puts $fp "bus change: [examine bus]"
close $fp
}

The following example is a little more sophisticated method of doing the same thing:

ModelSim Reference Manual, v10.1c 407

Commands
when

when -fast {$now == 0ns} {

set fp [open mylog.txt w]
}
when -fast {bus} {
puts $fp "bus change: [examine bus]"
}
when -fast {$now == 1000ns} {
close $fp
}

The general principle is that any embedded command done using the -fast argument is
global to all other commands used with the -fast argument. Here, {$now == 0ns} is a way to
define Tcl processes that the -fast commands can use. These processes have the same
restrictions that when bodies have, but the advantage is again speed as a proc will tend to
execute faster than code in the when body itself.
It is recommended not to use virtual signals and expressions.
Arguments
• -fast
(optional) Causes the embedded <command> to execute within the simulation kernel, which
provides faster execution and reduces impact on simulation runtime performance.
Limitations on using the -fast argument are described above (in “Embedded Commands Not
Allowed with the -fast Argument”). Disallowed commands still work, but they slow down
the simulation.
• -label <label>
(optional) Used to identify individual when commands.
<label> — Associates a name or label with the specified when command. Adds a level
of identification to the when command. The label may contain special characters.
Quotation marks (" ") or braces ({ }) are required only if <label> contains spaces or
special characters.
• -id <id#>
(optional) Attempts to assign this id number to the when command.
<id#> — Any positive integer that is not already assigned. If the id number you specify
is already used, ModelSim will return an error.
Note
Id numbers for when commands are assigned from the same pool as those used for the bp
command. So even if you have not specified a given id number for a when command, that
number may still be used for a breakpoint.

• {<when_condition_expression>}
(required if a command is specified) Specifies the conditions to be met for the specified
<command> to be executed. The condition is evaluated in the simulator kernel and can be
an object name, in which case the curly braces can be omitted. The command will be

408 ModelSim Reference Manual, v10.1c

Commands
when

executed when the object changes value. The condition can be an expression with these
operators:
Name Operator
equals ==, =
not equal !=, /=
greater than >
less than <
greater than or equal >=
less than or equal <=
AND &&, AND
OR ||, OR
The operands may be object names, signame'event, or constants. Subexpressions in
parentheses are permitted. The command will be executed when the expression is evaluated
as TRUE or 1.
The formal BNF syntax is:
condition ::= Name | { expression }

expression ::= expression AND relation

| expression OR relation
| relation
relation ::= Name = Literal
| Name /= Literal
| Name ' EVENT
| ( expression )
Literal ::= '<char>' | "<bitstring>" | <bitstring>

The "=" operator can occur only between a Name and a Literal. This means that you cannot
compare the value of two signals, i.e., Name = Name is not possible.
Tcl variables can be used in the condition expression but you must replace the curly braces
({}) with double quotes (""). This works like a macro substitution where the Tcl variables
are evaluated once and the result is then evaluated as the when condition. Condition
expressions are evaluated in the vsim kernel, which knows nothing about Tcl variables.
That's why the condition expression must be evaluated in the GUI before it is sent to the
vsim kernel. See below for an example of using a Tcl variable.
The ">", "<", ">=", and "<=" operators are the standard ones for vector types, not the
overloaded operators in the std_logic_1164 package. This may cause unexpected results
when comparing objects that contain values other than 1 and 0. ModelSim does a lexical
comparison (position number) for values other than 1 and 0. For example:

ModelSim Reference Manual, v10.1c 409

Commands
when

0000 < 1111 ## This evaluates to true

H000 < 1111 ## This evaluates to false
001X >= 0010 ## This also evaluates to false

• {<command>}
(required if a when expression is specified) The command(s) for this argument are evaluated
by the Tcl interpreter within the ModelSim GUI. Any ModelSim or Tcl command or series
of commands are valid with one exception—the run command cannot be used with the
when command. The command sequence usually contains a stop command that sets a flag
to break the simulation run after the command sequence is completed. Multiple-line
commands can be used.
Note
If you want to stop the simulation using a when command, you must use a stop command
within your when statement. DO NOT use an exit command or a quit command. The
stop command acts like a breakpoint at the time it is evaluated.

Examples
• The when command below instructs the simulator to display the value of object c in
binary format when there is a clock event, the clock is 1, and the value of b is 01100111.
Finally, the command tells ModelSim to stop.
when -label when1 {clk'event and clk=’1’ and b = "01100111"} {
echo "Signal c is [exa -bin c]"
stop
}

• The when command below echoes the simulator time when slice [3:1] of wire [15:0]
count matches the hexadecimal value 7, and simulation time is between 70 and 111
nanoseconds.
when {$now > 70ns and count(3:1) == 3'h7 && $now < 111ns} {
echo "count(3:1) matched 3'h7 at time " $now
}

• The commands below show an example of using a Tcl variable within a when
command. Note that the curly braces ({}) have been replaced with double quotes ("").
set clkb_path /tb/ps/dprb_0/udprb/ucar_reg/uint_ram/clkb;
when -label when1 "$clkb_path'event and $clkb_path ='1'" {
echo "Detected Clk edge at path $clkb_path"
}

• The when command below is labeled a and will cause ModelSim to echo the message
“b changed” whenever the value of the object b changes.
when -label a b {echo "b changed"}

• The multi-line when command below does not use a label and has two conditions. When
the conditions are met, ModelSim runs an echo command and a stop command.

410 ModelSim Reference Manual, v10.1c

Commands
when

when {b = 1
and c /= 0 } {
echo "b is 1 and c is not 0"
stop
}

• In the example below, for the declaration "wire [15:0] a;", the when command will
activate when the selected bits match a 7:
when {a(3:1) = 3'h7} {echo "matched at time " $now}

• In the example below, we want to sample the values of the address and data bus on the
first falling edge of clk after sstrb has gone high.
# ::strobe is our state variable
set ::strobe Zero
# This signal breakpoint only fires when sstrb changes to a '1'
when -label checkStrobe {/top/sstrb == '1'} {
# Our state Zero condition has been met, move to state One
set ::strobe One
}
# This signal breakpoint fires each time clk goes to '0'
when {/top/clk == '0'} {
if {$::strobe eq "One"} {
# Our state One condition has been met
# Sample the busses
echo Sample paddr=[examine -hex /top/paddr] :: sdata=[examine
-hex
/top/sdata]
# reset our state variable until next rising edge of sstrb
(back to
state Zero)
set ::strobe Zero
}
}

Ending the simulation with the stop command

Batch mode simulations are often structured as "run until condition X is true," rather than "run
for X time" simulations. The multi-line when command (shown below) sets a done condition,
and ModelSim runs an echo command and a stop command when the condition is reached.
The simulation will not stop (even if a quit -f command is used) unless you enter a stop
command. To exit the simulation and quit ModelSim, use an approach like the following:

ModelSim Reference Manual, v10.1c 411

Commands
when

onbreak {resume}
when {/done_condition == ’1’} {
echo "End condition reached"
if [batch_mode] {
set DoneConditionReached 1
stop
}
}
run 1000 us
if {$DoneConditionReached == 1} {
quit -f
}

This example stops 100ns after a signal transition:

when {a = 1} {
# If the 100ns delay is already set then let it go.
if {[when -label a_100] == ""} {
when -label a_100 { $now = 100 } {
# delete this breakpoint then stop
nowhen a_100
stop
}
}
}

Time-based breakpoints
You can build time-based breakpoints into a when statement with the following syntax.
For absolute time (indicated by @) use:
when {$now = @1750 ns} {stop}

You can also use:

when {errorFlag = '1' OR $now = 2 ms} {stop}

This example adds 2 ms to the simulation time at which the when statement is first evaluated,
then stops. The white space between the value and time unit is required for the time unit to be
understood by the simulator.
You can also use variables, as shown in the following example:
set time 1000
when "\$now = $time" {stop}

The quotes instruct Tcl to expand the variables before calling the command. So, the when
command sees:
when "$now = 1000" stop

Note that "$now" has the ‘$’ escaped. This prevents Tcl from expanding the variable, because if
it did, you would get:
when "0 = 1000" stop

412 ModelSim Reference Manual, v10.1c

Commands
when

Related Topics
• bp
• disablebp
• enablebp
• nowhen

ModelSim Reference Manual, v10.1c 413

Commands
where

where
This command displays information about the system environment. It is useful for debugging
problems where ModelSim cannot find the required libraries or support files.
The command displays two results on consecutive lines:
• current directory
This is the current directory that ModelSim was invoked from, or that was specified on
the ModelSim command line.
• current project file
This is the .mpf file ModelSim is using. All library mappings are taken from here when a
project is open. If the design is not loaded through a project, this line displays the
modelsim.ini file in the current directory.
Syntax
where
Arguments
• None.
Examples
• Design is loaded through a project:
VSIM> where

Returns:
# Current directory is: D:\Client
# Project is: D:/Client/monproj.mpf

• Design is loaded with no project (indicates the modelsim.ini file is under the mydesign
directory):
VSIM> where

Returns:
# Current directory is: C:\Client\testcase\mydesign
# Project is: modelsim.ini

414 ModelSim Reference Manual, v10.1c

Commands
wlf2log

wlf2log
This command translates a ModelSim WLF file (vsim.wlf) to a QuickSim II logfile. It reads the
vsim.wlf WLF file generated by the add list, add wave, or log commands in the simulator and
converts it to the QuickSim II logfile format.
Note
This command should be invoked only after you have stopped the simulation using
quit -sim or dataset close sim.

Syntax
wlf2log <wlffile> [-bits] [-fullname] [-help] [-inout] [-input] [-internal] [-l <instance_path>]
[-lower] [-o <outfile>] [-output] [-quiet]
Arguments
• <wlffile>
(required) Specifies the ModelSim WLF file that you are converting.
• -bits
(optional) Forces vector nets to be split into 1-bit wide nets in the log file.
• -fullname
(optional) Shows the full hierarchical pathname when displaying signal names.
• -help
(optional) Displays a list of command options with a brief description for each.
• -inout
(optional) Lists only the inout ports. This may be combined with the -input, -output, or
-internal switches.
• -input
(optional) Lists only the input ports. This may be combined with the -output, -inout, or
-internal switches.
• -internal
(optional) Lists only the internal signals. This may be combined with the -input, -output, or
-inout switches.
• -l <instance_path>
(optional) Lists the signals at or below an HDL instance path within the design hierarchy.
<instance_path> — Specifies an HDL instance path.
• -lower
(optional) Shows all logged signals in the hierarchy. When invoked without the -lower
switch, only the top-level signals are displayed.

ModelSim Reference Manual, v10.1c 415

Commands
wlf2log

• -o <outfile>
(optional) Directs the output to be written to a file where the default destination for the
logfile is standard out.
<outfile> — A user specified filename.
• -output
(optional) Lists only the output ports. This may be combined with the -input, -inout, or
-internal switches.
• -quiet
(optional) Disables error message reporting.

416 ModelSim Reference Manual, v10.1c

Commands
wlf2vcd

wlf2vcd
This command translates a ModelSim WLF file to a standard VCD file. Complex data types
that are unsupported in the VCD standard (records, memories, etc.) are not converted.
Note
This command should be invoked only after you have stopped the simulation using
quit -sim or dataset close sim.

Syntax
wlf2vcd <wlffile> [-help] [-o <outfile>] [-quiet]
Arguments
• <wlffile>
(required) Specifies the ModelSim WLF file that you are converting.
• -help
(optional) Displays a list of command options with a brief description for each.
• -o <outfile>
(optional) Specifies a filename for the output where the default destination for the VCD
output is stdout.
<outfile> — A user specified filename.
• -quiet
(optional) Disables warning messages that are produced when an unsupported type (for
example, records) is encountered in the WLF file.

ModelSim Reference Manual, v10.1c 417

Commands
wlfman

wlfman
This command allows you to get information about and manipulate saved WLF files.
The command performs four functions depending on which mode you use:
• wlfman info returns file information, resolution, versions, and so forth about the source
WLF file.
• wlfman items generates a list of HDL objects (i.e., signals) from the source WLF file
and outputs it to stdout. When redirected to a file, the output is called an object_list_file,
and it can be read in by wlfman filter. The object_list_file is a list of objects, one per
line. Comments start with a '#' and continue to the end of the line. Wildcards are legal in
the leaf portion of the name. Here is an example:
/top/foo # signal foo
/top/u1/* # all signals under u1
/top/u1 # same as line above
-r /top/u2 # recursively, all signals under u2

Note that you can produce these files from scratch but be careful with syntax. wlfman
items always creates a legal object_list_file.
• wlfman filter reads in a WLF file and, optionally, an object_list_file, and writes a new
WLF file containing filtered information from those sources. You determine the filtered
information with the arguments you specify.
• wlfman monitor returns the current state of a WLF file to the transcript. Each time the
state is monitored, a line of information is output. The state of the WLF file can be
monitored at regular intervals, indicating the changes over time. Here is an example:
wlfman monitor visim.wlf
File Sim
State Time
closed 14000

• wlfman profile generates a report of the estimated percentage of file space that each
signal is taking in the specified WLF file. This command can identify signals that
account for a large percentage of the WLF file size (such as a logged memory that uses a
zero-delay integer loop to initialize the memory). You may be able to drastically reduce
WLF file size by not logging those signals.
• wlfman merge combines two WLF files with different signals into one WLF file. It
does not combine wlf files containing the same signals at different runtime ranges (i.e.,
mixedhdl_0ns_100ns.wlf & mixedhdl_100ns_200ns.wlf).
• wlfman optimize copies the data from the WLF file to the output WLF file, adding or
replacing the indexing and optimization information.
The different modes are intended to be used together. For example, you might run wlfman
profile and identify a signal that accounts for 50% of the WLF file size. If you don’t actually
need that signal, you can then run wlfman filter to remove it from the WLF file.

418 ModelSim Reference Manual, v10.1c

Commands
wlfman

Syntax
wlfman info <source_wlffile> [-v]
wlfman items <source_wlffile> [-n] [-v]
wlfman filter -o <out_wlffile> <source_wlffile> [-begin <time>] [-end <time>]
[-compress | -nocompress] [-f <object_list_file>] [-index | -noindex] [-r <object>]
[-opt | -noopt] [-s <symbol>] [-t <resolution>]
wlfman profile <source_wlffile> [-rank] [-top <number>]
wlfman merge -o <out_wlffile> [<wlffile1> <wlffile2> ...] [-compress | -nocompress]
[-index | -noindex] [-opt | -noopt]
wlfman monitor [-f | -i <intervalTime> | -p <endTime>] [-q | -v] <source_wlffile>
wlfman optimize -o <out_wlffile> <source_wlffile> [-opt | -noopt]
Arguments
• -o <out_wlffile>
(required) Specifies the name of the output WLF file. The output WLF file will contain all
objects specified by the preceding arguments. Output WLF files are always written in the
latest WLF version regardless of the source WLF file version.
• <source_wlffile>
(required) Specifies the WLF file from which you want information.
• <wlffile1> <wlffile2> ...
(required) Specifies the WLF files whose objects you want to copy into one WLF file.
Specified as a space separated list.
• -begin <time>
(optional) Specifies the simulation time at which to start reading information from the
source WLF file where the default is to include the entire length of time recorded in
<source_wlffile>.
• -compress | -nocompress
(optional) Controls compression of the output WLF file.
-compress — Enables compression. (default)
-nocompress — Disables compression.
• -end <time>
(optional) Specifies the simulation time at which you want to end reading information from
<source_wlffile>.
• -f
(optional) Repeat status update every 10 seconds of real time unless an alternate time
interval is specified with -i <intervalTime>.

ModelSim Reference Manual, v10.1c 419

Commands
wlfman

• -f <object_list_file>
(optional) Specifies an object_list_file created by wlfman items to include in
<out_wlffile>.
• -i <intervalTime>
(optional) Specifies the time delay before the next status update where the default is 10
seconds of real time if not specified.
<intervalTime> — Any positive integer.
• -index | -noindex
(optional) Controls indexing when writing the output WLF file. Indexing makes viewing
wave data faster, however performance during optimization will be slower because indexing
and optimization require significant memory and CPU resources. Disabling indexing makes
viewing wave data slower unless the display is near the start of the WLF file. Disabling
indexing also disables optimization of the WLF file but may provide a significant
performance boost when archiving WLF files. Indexing and optimization information can
be added back to the file using the wlfman optimize command.
-index — Enables indexing. (default)
-noindex — Disables indexing and optimization.
• -n
(optional) Lists regions only (no signals).
• -opt | -noopt
(optional) Controls optimization of the output WLF file.
-opt — Enables WLF file optimization. (default)
-noopt — Disables WLF file optimization.
• -p <endTime>
(optional) Specifies the simulation time at which wlfman will stop monitoring the WLF file.
<endTime> — Any positive integer.
• -q
(optional) Suppress normal status messages while monitoring.
• -r <object>
(optional) Specifies an object (region) to recursively include in the output. If <object> is a
signal, the output would be the same as using -s.
• -rank
(optional) Sorts the wlfman profile report by percentage of the total file space used by each
signal.
• -s <symbol>
(optional) Specifies an object to include in the output. By default all objects are included.

420 ModelSim Reference Manual, v10.1c

Commands
wlfman

• -t <resolution>
(optional) Specifies the time resolution of the new WLF file. By default the resolution is the
same as the source WLF file.
• -top <number>
(optional) Filters the wlfman profile report so that only the top <number> signals in terms
of file space percentage are displayed.
• -v
(optional) Produces verbose output that lists the object type next to each object.
Examples
• The output from this command would look something like this:
wlfman profile -rank top_vh.wlf

Returns:
#Repeated ID #'s mean those signals share the same
#space in the wlf file.
#
# ID Transitions File % Name
#----- ----------- ------ ------------------------------------
1 2192 33 % /top_vh/pdata
1 /top_vh/processor/data
1 /top_vh/cache/pdata
1 /top_vh/cache/gen__0/s/data
1 /top_vh/cache/gen__1/s/data
1 /top_vh/cache/gen__2/s/data
1 /top_vh/cache/gen__3/s/data
2 1224 18 % /top_vh/ptrans
3 1216 18 % /top_vh/sdata
3 /top_vh/cache/sdata
3 /top_vh/memory/data
4 675 10 % /top_vh/strans
5 423 6 % /top_vh/cache/gen__3/s/data_out
6 135 3 % /top_vh/paddr.
.
.
.
• wlfman profile -top 3 top_vh.wlf
The output from this command would look something like this:

ModelSim Reference Manual, v10.1c 421

Commands
wlfman

# ID Transitions File % Name

#----- ----------- ------ ------------------------------------
1 2192 33 % /top_vh/pdata
1 /top_vh/processor/data
1 /top_vh/cache/pdata
1 /top_vh/cache/gen__0/s/data
1 /top_vh/cache/gen__1/s/data
1 /top_vh/cache/gen__2/s/data
1 /top_vh/cache/gen__3/s/data
2 1224 18 % /top_vh/ptrans
3 1216 18 % /top_vh/sdata
3 /top_vh/cache/sdata
3 /top_vh/memory/data

• wlfman monitor -f -p 100000000 vsim.wlf

Returns:
Setting end time to 100000000, measuring progress %
File File Percent
State Time Complete
open 7239185 7.2%
open 7691785 7.7%
open 8144385 8.1%
open 8596625 8.6%

Related Topics
• Recording Simulation Results With
Datasets
• WLF File Parameter Overview

422 ModelSim Reference Manual, v10.1c

Commands
wlfrecover

wlfrecover
This command attempts to "repair" WLF files that are incomplete due to a crash or if the file
was copied prior to completion of the simulation. Use this command if you receive a “bad
magic number” error message when opening a WLF file. You can run the command from the
VSIM> or ModelSim> prompt or from a shell.
Syntax
wlfrecover <filename> [-force] [-q]
Arguments
• <filename>
(required) Specifies the WLF file to repair.
• -force
(optional) Disregards file locking and attempts to repair the file.
• -q
(optional) Hides all messages unless there is an error while repairing the file.
Related Topics
• Saving a Simulation to a WLF File

ModelSim Reference Manual, v10.1c 423

Commands
write format

write format
This command records the names and display options of the HDL objects currently being
displayed in the Analysis, List, Memory, Message Viewer, Test Browser, and Wave windows.
The write format restart command creates a single .do file that will recreate all debug
windows, all file/line breakpoints, and all signal breakpoints created using the when command.
If the ShutdownFile modelsim.ini variable is set to this .do filename, it will call the write format
restart command upon exit.
The file created is primarily a list of add list or add wave commands, though a few other
commands are included (see "Output" below). This file may be invoked with the do command
to recreate the window format on a subsequent simulation run.
When you load a format file, ModelSim verifies the existence of the datasets required by that
file. ModelSim displays an error message if the requisite datasets do not all exist. To force the
execution of the format file even if all datasets are not present, use the -force switch with your
do command. For example:
VSIM> do format.do -force

Note
Note that using the -force switch when datasets are not present will result in error
messages for signals referencing the nonexistent datasets. Also, -force is recognized by
the format file not the do command.

Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
write format {assertions | breakpoints | coverdirective | export_hier_config | list | memory
| msgviewer | testbrowser | watch | wave | restart}
<filename>
Arguments
• assertions | breakpoints | coverdirective | export_hier_config | list | memory | msgviewer
| testbrowser | watch | wave | restart
(required) Specifies that the contents of the designated window are recorded in the file
specified by <filename>.
assertions — Records objects of the Assertions window.
breakpoints — Records file line and signal breakpoints.
coverdirective — Records objects of the Coverdirectives window.
export_hier_config — Records hierarchical sort order for objects in the Verification
Results Analysis window.
list — Records objects of the List window.

424 ModelSim Reference Manual, v10.1c

Commands
write format

memory — Records objects of the Memory window.

msgviewer — Records objects of the Message Viewer window.
testbrowser — Records objects of the Verification Management Browser window.
watch — Records objects of the Watch window.
wave — Records objects of the Wave window.
restart — Records objects of all windows and breakpoints in the .do file.
• <filename>
(required) Specifies the name of the output file where the data is to be written. You must
specify the .do extension.
Examples
• Save the current data in the List window in a file named alu_list.do.
write format list alu_list.do

• Save the current data in the Wave window in a file named alu_wave.do.
write format wave alu_wave.do

Output
• Below is an example of a saved Wave window format file.
onerror {resume}
quietly WaveActivateNextPane {} 0
add wave -noupdate -format Logic /cntr_struct/ld
add wave -noupdate -format Logic /cntr_struct/rst
add wave -noupdate -format Logic /cntr_struct/clk
add wave -noupdate -format Literal /cntr_struct/d
add wave -noupdate -format Literal /cntr_struct/q
TreeUpdate [SetDefaultTree]
quietly WaveActivateNextPane
add wave -noupdate -format Logic /cntr_struct/p1
add wave -noupdate -format Logic /cntr_struct/p2
add wave -noupdate -format Logic /cntr_struct/p3
TreeUpdate [SetDefaultTree]
WaveRestoreCursors {0 ns}
WaveRestoreZoom {0 ns} {1 us}
configure wave -namecolwidth 150
configure wave -valuecolwidth 100
configure wave -signalnamewidth 0
configure wave -justifyvalue left

In the example above, five signals are added with the -noupdate argument to the default
window. The TreeUpdate command then refreshes all five waveforms. The second
WaveActivateNextPane command creates a second pane which contains three
signals.The WaveRestoreCursors command restores any cursors you set during the
original simulation, and the WaveRestoreZoom command restores the Zoom range you

ModelSim Reference Manual, v10.1c 425

Commands
write format

set. These four commands are used only in saved Wave format files; therefore, they are
not documented elsewhere.
Related Topics
• add list
• add wave
•

426 ModelSim Reference Manual, v10.1c

Commands
write list

write list
This command records the contents of the List window in a list output file.
This file contains simulation data for all HDL objects displayed in the List window: VHDL
signals and variables and Verilog nets and registers.
Arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
write list [-events] <filename>
Arguments
• -events
(optional) Specifies to write print-on-change format where the default is tabular format.
• <filename>
(required) Specifies the name of the output file where the data is to be written.
Examples
• Save the current data in the List window in a file named alu.lst.
write list alu.lst

Related Topics
• write tssi

ModelSim Reference Manual, v10.1c 427

Commands
write preferences

write preferences
This command saves the current GUI preference settings to a Tcl preference file. Settings saved
include Wave, Objects, and Locals window column widths; Wave, Objects, and Locals window
value justification; and Wave window signal name width.
Syntax
write preferences <preference file name>
Arguments
• <preference file name>
(required) Specifies the name for the preference file. If the file is named modelsim.tcl,
ModelSim will read the file each time vsim is invoked. To use a preference file other than
modelsim.tcl you must specify the alternative file name with the MODELSIM_TCL
environment variable.
You can modify variables by editing the preference file with the ModelSim notepad:

notepad <preference file name>

428 ModelSim Reference Manual, v10.1c

Commands
write report

write report
This command prints a summary of the design being simulated including a list of all design
units (VHDL configurations, entities, and packages, and Verilog modules) with the names of
their source files. The summary includes a list of all source files used to compile the given
design.
The Simulation Report contains the following information:
• Design Simulated — directory path of the design’s top-level module
• Number of signals/nets in the design
• Number of processes in the design
• Simulator Parameters, including:
o Current directory
o Project file directory
o Simulation time resolution
• List of design units used, including:
o Module name
o Architecture, if applicable
o Library directory
o Source file
o Timescale
o Occurrences
Some arguments to this command are order-dependent. Please read through the argument
descriptions for more information.
Syntax
write report [-capacity [-l | -s] [-qdas]] | [-l | -s] |
[-tcl] | [<filename>]
Arguments
• -capacity
(optional) Reports data on memory usage of various types of SystemVerilog constructs in
the design. ModelSim collects memory usage data for dynamic objects. Must be specified
first when specifying -qdas. To display memory data for all object types, specify -capacity -
l.

ModelSim Reference Manual, v10.1c 429

Commands
write report

• <filename>
(optional) Specifies the name of the output file where the data is to be written. If <filename>
is omitted, the report is written to the Transcript window.
• -l
(optional) Generates more detailed information about the design, including a list of sparse
memories or the memory capacity for all object types. You must precede this argument with
-capacity when specifying a capacity report.
• -qdas
(optional) Reports memory usage data for queues, dynamic arrays, and associative arrays.
You must precede this argument with -capacity when specifying a capacity report.
• -s
(optional) Generates a short list of design information. You must precede this argument with
-capacity when specifying a capacity report.
• -tcl
(optional) Generates a Tcl list of design unit information. This argument cannot be used
with a filename.
Examples
• Save information about the current design in a file named alu_rpt.txt.
write report alu_rpt.txt

•
Create a Simulation Report for the current simulation
write report -l

returns:
##
## SIMULATION REPORT Generated on Mon Aug 10 12:56:15 2009
##
##
## Design simulated: <directory>\work.top(fast)
## Number of signals/nets in design: 89
## Number of processes in design: 74
##
## Simulator Parameters:
##
## Current directory: <directory>\
## Project file: <directory>\win32/../modelsim.ini
## Simulation time resolution: 1ns
##
## List of Design units used:
##
## Module: top
## Architecture: fast
## Library: <directory>\work

430 ModelSim Reference Manual, v10.1c

Commands
write report

## Source File: top.v

## Timescale: 1ns / 1ns
## Occurrences: 1
##
## Module: proc
## Architecture: fast
## Library: <directory>\work
## Source File: proc.v
## Timescale: 1ns / 1ns
## Occurrences: 1

...

ModelSim Reference Manual, v10.1c 431

Commands
write timing

write timing
This command displays path delays and timing check limits, unadjusted for delay net delays, for
the specified instance.
When the write timing command reports interconnect delays on a Verilog module instance you
will see either MIPDs (Module Input Port Delays) or MITDs (Module Transport Port Delays)
reported. If you specify either the +multisource_int_delays or the +transport_int_delays
switch with the vsim command, INTERCONNECT delays will be reported as MITDs.
Otherwise they will be reported as MIPDs. An MIPD report may look like the following:
# /top/u1: [mymod:src/5/test.v(18)]
# MIPD(s):
# Port clk_in: (6, 6, 6)

An MITD report may look like the following:

# /top/u1: [mymod:src/5/test.v(18)]
# MITDs to port clk_in:
# From port /top/p/y = (6)

Syntax
write timing [-recursive] [-file <filename>] [<instance_name1>…<instance_nameN>]
[-simvalues]
Arguments
• -file <filename>
(optional) Specifies the name of the output file where the data is to be written. If the -file
argument is omitted, timing information is written to the Transcript window.
<filename> — Any valid filename. May include special characters and numbers.
• <instance_name1>…<instance_nameN>
(required) The name(s) of the instance(s) for which timing information will be written. If
<instance_name> is omitted, the command returns nothing.
• -recursive
(optional) Generates timing information for the specified instance and all instances
underneath it in the design hierarchy.
• -simvalues
(optional) Displays optimization-adjusted values for delay net delays.
Examples
• Write timing about /top/u1 and all instances underneath it in the hierarchy to the file
timing.txt.
write timing -r -f timing.txt /top/u1

432 ModelSim Reference Manual, v10.1c

Commands
write timing

• Write timing information about the designated instances to the Transcript window.
write timing /top/u1 /top/u2 /top/u3 /top/u8

ModelSim Reference Manual, v10.1c 433

Commands
write transcript

write transcript
This command writes the contents of the Transcript window to the specified file. The resulting
file can then be modified to replay the transcribed commands as a DO file (macro).
The command cannot be used in batch mode. In batch mode use the standard Transcript file or
redirect stdout.
Syntax
write transcript [<filename>]
Arguments
• <filename>
(optional) Specifies the name of the output file where the data is to be written. If the
<filename> is omitted, the transcript is written to a file named transcript.
Related Topics
• do
• Saving a Transcript File as a Macro (DO
file)

434 ModelSim Reference Manual, v10.1c

Commands
write tssi

write tssi
This command records the contents of the List window in a "TSSI format" file.
The file contains simulation data for all HDL objects displayed in the List window that can be
converted to TSSI format (VHDL signals and Verilog nets). A signal definition file is also
generated.
The List window needs to be using symbolic radix in order for write tssi to produce useful
output.
Syntax
write tssi <filename>
Arguments
• <filename>
(required) Specifies the name of the output file where the data is to be written.
Description
If the <filename> has a file extension (e.g., listfile.lst), then the definition file is given the same
file name with the extension .def (e.g., listfile.def). The values in the listfile are produced in the
same order that they appear in the List window. The directionality is determined from the port
type if the object is a port, otherwise it is assumed to be bidirectional (mode INOUT).
Objects that can be converted to SEF are VHDL enumerations with 255 or fewer elements and
Verilog nets. The enumeration values U, X, 0, 1, Z, W, L, H and - (the enumeration values
defined in the IEEE Standard 1164 std_ulogic enumeration) are converted to SEF values
according to the table below. Other values are converted to a question mark (?) and cause an
error message. Though the write tssi command was developed for use with std_ulogic, any
signal which uses only the values defined for std_ulogic (including the VHDL standard type
bit) will be converted.
std_ulogic State SEF State Characters
Characters
Input Output Bidirectional
U N X ?
X N X ?
0 D L 0
1 U H 1
Z Z T F
W N X ?
L D L 0
H U H 1

ModelSim Reference Manual, v10.1c 435

Commands
write tssi

std_ulogic State SEF State Characters

Characters
Input Output Bidirectional
- N X ?
Bidirectional logic values are not converted because only the resolved value is available. The
TSSI TDS ASCII In Converter and ASCII Out Converter can be used to resolve the
directionality of the signal and to determine the proper forcing or expected value on the port.
Lowercase values x, z, w, l, and h are converted to the same values as the corresponding
capitalized values. Any other values will cause an error message to be generated the first time
an invalid value is detected on a signal, and the value will be converted to a question mark (?).
Note
The TDS ASCII In Converter and ASCII Out Converter are part of the TDS software.
ModelSim outputs a vector file, and TSSI tools determine whether the bidirectional
signals are driving or not.

Related Topics
• tssi2mti

436 ModelSim Reference Manual, v10.1c

Commands
write wave

write wave
This command records the contents of the Wave window in PostScript format.
The output file can then be printed on a PostScript printer.
Syntax
write wave <filename> [-end <time>] [-landscape] [-height <real_num>]
[-margin <real_num>] [-perpage <time>] [-portrait][-start <time>] [-width <real_num>]

Arguments
• <filename>
(required) Specifies the name of the PostScript (.ps) output file.
• -end <time>
(optional) The simulation time at which the record will end.
<time> — Specified as a positive integer or decimal number where the units are the
current simulation time resolution.
• -height <real_num>
(optional) Specifies the paper height in inches.
<real_num> — Specified as a positive integer or decimal number where the default is
11.0.
• -landscape
(optional) Use landscape (horizontal) orientation. (default)
• -margin <real_num>
(optional) Specifies the margin in inches.
<real_num> — Specified as a positive integer or decimal number where the default is
0.5.
• -perpage <time>
(optional) Specifies the time width per page of output.
<time> — Specified as a positive integer or decimal number where the units are the
current simulation time resolution.
• -portrait
(optional) Use portrait (vertical) orientation where the default is landscape (horizontal).
• -start <time>
(optional) Specifies the start time to be written.
<time> — Specified as a positive integer or decimal number where the units are the
current simulation time resolution.

ModelSim Reference Manual, v10.1c 437

Commands
write wave

• -width <real_num>
(optional) Specifies the paper width in inches.
<real_num> — Specified as a positive integer or decimal number where the default is
8.5.
Examples
• Save the current data in the Wave window in a file named alu.ps.
write wave alu.ps

• Write two separate pages to top.ps. The first page contains data from 600ns to 700ns,
and the second page contains data from 701ns to 800ns.
write wave -start 600ns -end 800ns -perpage 100ns top.ps

To make the job of creating a PostScript waveform output file easier, use the File >
Print Postscript menu selection in the Wave window.

438 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Index

halting, 411
Index

— Symbols — bd (breakpoint delete) command, 73

’hasX, hasX, 30 binary radix, mapping to std_logic values, 37
+typdelays, 343 bookmark add wave command, 75
$finish behavior, customizing, 376 bookmark delete wave command, 77
— Numerics — bookmark goto wave command, 78
2001, keywords, disabling, 344 bookmark list wave command, 79
bp (breakpoint) command, 80
—A— break
abort command, 48 on signal value, 406
absolute time, using @, 22 breakpoints
add dataflow command, 49 conditional, 406
add list command, 51 continuing simulation after, 217
add log command, 156 deleting, 73
add memory, 55 listing, 80
add memory command, 55 setting, 80
add message command, 57 signal breakpoints (when statements), 406
add watch command, 59 time-based
add wave command, 60 in when statements, 412
add_cmdhelp command, 67 busses
AddPragmaPrefix .ini file variable, 330 user-defined, 64
addTime command, 241
alias command, 69 —C—
analog call command, 86
signal formatting, 61 case choice, must be locally static, 282
annotating interconnect delays, case sensitivity
v2k_int_delays, 378 VHDL vs. Verilog, 17
archives, library, 327 cd (change directory) command, 88
argument, 337 change command, 89
arrays -check_synthesis argument, 277
indexes, 13 class objects, viewing, 91
slices, 13 classinfo command, 91
arrays, VHDL, searching for, 26 Color
assertions radix, 204
testing for with onbreak command, 187 example, 205
attributes, of signals, using in expressions, 30 combining signals, busses, 64
commands
—B— abort, 48
batch_mode command, 72 add dataflow, 49
batch-mode simulations add list, 51

ModelSim Reference Manual, v10.1c 439

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

add memory, 55 mem compare, 161

add message, 57 mem display, 162
add watch, 59 mem list, 165
add wave, 60 mem load, 166
alias, 69 mem save, 170
batch_mode, 72 mem search, 173
bd (breakpoint delete), 73 messages clearfilter, 176, 177
bookmark add wave, 75 messages write, 178
bookmark delete wave, 77 noforce, 180
bookmark goto wave, 78 nolog, 181
bookmark list wave, 79 notation conventions, 11
bp (breakpoint), 80 notepad, 183
call, 86 noview, 184
cd (change directory), 88 nowhen, 185
change, 89 onbreak, 186
classinfo, 91 onElabError, 188
configure, 95 onerror, 189
dataset alias, 101 pause, 192
dataset clear, 102 printenv, 193, 194
dataset close, 103 process report, 195
dataset config, 104, 106 pwd, 199
dataset info, 107 quietly, 200
dataset list, 108 quit, 201
dataset open, 109 radix, 202
dataset rename, 110, 112 radix define, 204
dataset restart, 111 radix list, 208
dataset snapshot, 113 radix name, 209
delete, 116 readers, 211
describe, 117 report, 212
disablebp, 118 restart, 214
do, 119 resume, 216
drivers, 121 run, 217
dumplog64, 123 runStatus, 220
echo, 124 searchlog, 222
edit, 125 see, 225
enablebp, 126 setenv, 226
environment, 128 shift, 227
examine, 130 show, 228
exit, 135 simstats, 229
find, 136 stack down, 231
force, 145 stack frame, 232
layout, 154 stack level, 233
log, 156 stack tb, 234
lshift, 159 stack up, 235
lsublist, 160 status, 236

440 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

stop, 238 virtual region, 318

suppress, 239 virtual save, 319
tb (traceback), 240 virtual show, 320
Time, 241 virtual signal, 321
transcript, 244 vlib, 327
transcript file, 245 vlog, 329
transcript path, 247 vmake, 347
transcript sizelimit, 248 vmap, 349
TreeUpdate, 425 vsim, 351
tssi2mti, 249 vsimDate, 381
unsetenv, 252 vsimId, 381
variables referenced in, 22 vsimVersion, 381
vcd add, 253 vsource, 383
vcd checkpoint, 255 wave, 384
vcd comment, 256 wave create, 388
vcd dumpports, 257 wave edit, 394
vcd dumpportsall, 260 wave export, 397
vcd dumpportsflush, 261 wave import, 399
vcd dumpportslimit, 262 wave modify, 400
vcd dumpportsoff, 263 wave sort, 405
vcd dumpportson, 264 WaveActivateNextPane, 425
vcd file, 265 WaveRestoreCursors, 425
vcd files, 267 WaveRestoreZoom, 425
vcd flush, 269 when, 406
vcd limit, 270 where, 414
vcd off, 271 wlf2log, 415
vcd on, 272 wlf2vcd, 417
vcom, 275 wlfman, 418
vdel, 288 wlfrecover, 423
vdir, 290 write format, 424
vencrypt, 293 write list, 427
verror, 295 write preferences, 428
vgencomp, 297 write report, 429
vhencrypt, 299 write timing, 432
view, 301 write transcript, 434
virtual count, 304 write tssi, 435
virtual define, 305 write wave, 437
virtual delete, 306 comment characters in VSIM commands, 11
virtual describe, 307 compatibility, of vendor libraries, 290
virtual expand, 308 compiling
virtual function, 309 range checking in VHDL, 285
virtual hide, 312 Verilog, 329
virtual log, 313 VHDL, 275
virtual nohide, 315 at a specified line number, 280
virtual nolog, 316 selected design units (-just eapbc), 280

ModelSim Reference Manual, v10.1c 441

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

standard package (-s), 285, 342 design loading, interrupting, 351

VHDL-2008 design units
REAL_VECTOR, 279 report of units simulated, 429
compressing files Verilog
VCD files, 257, 267 adding to a library, 329
concatenation directories
directives, 35 mapping libraries, 349
of signals, 35 disablebp command, 118
conditional breakpoints, 406 dividers
configurations, simulating, 351 adding from command line, 61
configure command, 95 divTime ccommand, 241
constants do command, 119
in case statements, 282 DO files (macros), 119
values of, displaying, 117, 130 -dpiheader, vlog, 332, 372
conversion drivers command, 121
radix, 202 dump files, viewing in the simulator, 273
dumplog64 command, 123
—D—
dataset alias command, 101 —E—
dataset clear command, 102 echo command, 124
dataset close command, 103 edit command, 125
dataset config command, 104, 106 enablebp command, 126
dataset info command, 107 entities, specifying for simulation, 379
dataset list command, 108 environment command, 128
dataset open command, 109 environment variables
dataset rename command, 110, 112 reading into Verilog code, 331
dataset restart command, 111 specifying UNIX editor, 125
dataset snapshot command, 113 state of, 194
datasets using in pathnames, 17
environment command, specifying with, environment, displaying or changing
128 pathname, 128
declarations, hiding implicit with explicit, 287 eqTime command, 241
+define+, 331 errors
delay getting details about messages, 295
interconnect, 359 onerror command, 189
+delay_mode_distributed, 332 SDF, disabling, 363
+delay_mode_path, 332 event order
+delay_mode_unit, 332 changing in Verilog, 331
+delay_mode_zero, 332 examine command, 130
’delayed, 30 exit command, 135
delete command, 116 exiting the simulator, customizing behavior,
deltas 376
collapsing in WLF files, 368 extended identifier, 29
dependencies, checking, 290 extended identifiers, 17
dependency errors, 278, 333
describe command, 117

442 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

—F— interconnect delays, 359

-f, 333 annotating per Verilog 2001, 378
file compression internal signals, adding to a VCD file, 253
VCD files, 257, 267 interrupting design loading, 351
find command, 136 intToTime command, 241
find connections command, 141
force —K—
keywords
remove wire model, 361
disabling 2001 keywords, 344
force command, 145
enabling SystemVerilog keywords, 342
format file
List window, 424 —L—
Wave window, 424 layout command, 154
formatTime command, 242 LD_LIBRARY_PATH, disabling default
internal setting of, 359
—G—
generics +libcell, 336
assigning or overriding values with -g and - libraries
G, 355 archives, 327
examining generic values, 130 dependencies, checking, 290
limitation on assigning composite types, design libraries, creating, 327
356 listing contents, 290
glitches refreshing library images, 285, 341
disabling generation vendor supplied, compatibility of, 290
from command line, 370 Verilog, 358
global visibility lint-style checks, 336
PLI/FLI shared objects, 357 List window
gotolingk MGCGOTOVAR_user adding items to, 51
DPI File Loading, 378 loading designs, interrupting, 351
gteTime command, 241 log command, 156
gtTime command, 241 log file
GUI_expression_format, 27 log command, 156
syntax, 27 nolog command, 181
QuickSim II format, 415
—H— redirecting with -l, 358
’hasX, 30 virtual log command, 313
hazards virtual nolog command, 316
-hazards argument to vlog, 335 lshift command, 159
-hazards argument to vsim, 373 lsublist command, 160
history lteTime command, 241
of commands ltTime command, 241
shortcuts for reuse, 24
—M—
—I— macros (DO files)
implicit operator, hiding with vcom -explicit, breakpoints, executing at, 81
287 executing, 119
+incdir+, 335 forcing signals, nets, or registers, 145

ModelSim Reference Manual, v10.1c 443

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

parameters -no_risefall_delaynets, 374

passing, 119 noforce command, 180
relative directories, 119 +nolibcell, 336
shifting parameter values, 227 nolog command, 181
+maxdelays, 337 notepad command, 183
mc_scan_plusargs, PLI routine, 376 noview command, 184
mem compare command, 161 +nowarn<CODE>, 339
mem display command, 162 nowhen command, 185
mem list command, 165
mem load command, 166 —O—
mem save command, 170 object_list_file, WLF files, 418
mem search command, 173 onbreak command, 186
memory window onElabError command, 188
add memory command, 55 onerror command, 189
adding items to, 55 optimizations
memory, comparing contents, 161 disabling for Verilog designs, 340
memory, displaying contents, 162 optimizing wlf files, 418
memory, listing, 165 order of events
memory, loading contents, 166 changing in Verilog, 331
memory, saving contents, 170 —P—
memory, searching for patterns, 173 parameters
Message Viewer window using with macros, 119
messages write command, 178 pathnames
messages in VSIM commands, 12
echoing, 124 spaces in, 12
getting more information, 295 pause command, 192
loading, disabling with -quiet, 341 PLI
loading, disbling with -quiet, 285 loading shared objects with global symbol
messages clearfilter command, 176, 177 visibility, 357
messages write command, 178 pragmas
-mfcu, 337 synthesis pragmas, 276, 330
+mindelays, 337 preference variables
mulTime command, 241 WildcardFilter, 18
multi-source interconnect delays, 359 Preoptimized Design Unit
—N— and SDF file, 363
name case sensitivity, VHDL vs. Verilog, 17 printenv command, 193, 194
negative pulses process report command, 195
driving an error state, 377 projects
neqTime command, 241 override mapping for work directory with
nets vcom, 286
drivers of, displaying, 121 override mapping for work directory with
readers of, displaying, 211 vlog, 344
stimulus, 145 propagation, preventing X propagation, 360
values of pulse error state, 377
examining, 130 pwd command, 199

444 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

—Q— search libraries, 358

QuickSim II logfile format, 415 searching
quietly command, 200 binary signal values in the GUI, 37
quit command, 201 List window
signal values, transitions, and names,
—R— 27
Radix VHDL arrays, 26
color, 204 searchlog command, 222
example, 205 see command, 225
user defined, 204 setenv command, 226
radix shared objects
display values in debug windows, 202 loading with global symbol visibility, 357
of signals being examined, 53, 63, 132 shift command, 227
radix command, 202 shortcuts
Radix define command, 204 command history, 24
setting radix color, 204, 205 command line caveat, 24
radix list command, 208 show command, 228
radix name command, 209 signals
range checking alternative names in the Wave window (-
disabling, 283 label), 62
enabling, 285 attributes of, using in expressions, 30
readers command, 211 breakpoints, 406
RealToTime command, 242 combining into a user-defined bus, 64
record field selection, syntax, 13 drivers of, displaying, 121
refresh, dependency check errors, 278, 333 environment of, displaying, 128
refreshing library images, 285, 341 force time, specifying, 148
report command, 212 log file, creating, 156
reporting pathnames in VSIM commands, 12
processes in the Process Window, 195 radix
variable settings, 22 specifying for examine, 53, 63, 132
resolution readers of, displaying, 211
specifying with -t argument, 364 stimulus, 145
restart command, 214 values of
resume command, 216 examining, 130
run command, 217 simstats command, 229
runStatus command, 220 simulating
—S— delays, specifying time units for, 22
scaleTime command, 242 design unit, specifying, 351
scope resolution operator, 14 saving simulations, 156, 367
scope, setting region environment, 128 stopping simulation in batch mode, 411
SDF simulations
annotation verbose mode, 364 saving results, 112, 113
controlling missing instance messages, 363 Simulator commands, 48
errors on loading, disabling, 363 simulator resolution
warning messages, disabling, 364 vsim -t argument, 364

ModelSim Reference Manual, v10.1c 445

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

simulator version, 367, 381 time, time units, simulation time, 22

simultaneous events in Verilog timescale directive warning
changing order, 331 disabling, 375
spaces in pathnames, 12 timing
sparse memories disabling checks, 339
listing with write report, 430 disabling checks for entire design, 360
specify path delays, 377 title, Main window, changing, 365
stack down command, 231 transcript
stack frame command, 232 redirecting with -l, 358
stack level command, 233 transcript command, 244
stack tb command, 234 transcript file command, 245
stack up command, 235 transcript path command, 247
startup transcript sizelimit command, 248
alternate to startup.do (vsim -do), 354 TreeUpdate command, 425
status command, 236 TSCALE, disabling warning, 375
Std_logic TSSI, 435
mapping to binary radix, 37 tssi2mti command, 249
stop command, 238
subTime command, 241 —U—
suppress command, 239 -u, 343
synthesis undeclared nets, reporting an error, 336
pragmas, 276, 330 unsetenv command, 252
rule compliance checking, 277 user-defined bus, 64
SystemVerilog User-defined radix, 204
enabling with -sv argument, 342 —V—
multiple files in a compilation unit, 337 -v, 343
scope resolution, 14 v2k_int_delays, 378
SystemVerilog classes validTime command, 242
call command, 86 values
—T— describe HDL items, 117
tb command, 240 examine HDL item values, 130
Tcl variable settings report, 22
history shortcuts, 24 variables
variable describing, 117
in when commands, 409 referencing in commands, 22
TFMPC value of
disabling warning, 375 changing from command line, 89
time examining, 130
absolute, using @, 22 vcd add command, 253
simulation time units, 22 vcd checkpoint command, 255
time collapsing, 368 vcd comment command, 256
Time commands, 241 vcd dumpports command, 257
time resolution vcd dumpportsall command, 260
setting vcd dumpportsflush command, 261
with vsim command, 364 vcd dumpportslimit command, 262

446 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

vcd dumpportsoff command, 263 arrays

vcd dumpportson command, 264 searching for, 26
vcd file command, 265 compile
VCD files 1076-1987, 276
adding items to the file, 253 1076-1993, 276
capturing port driver data, 257 1076-2002, 276
converting to WLF files, 273 1076-2008, 276
creating, 253 field naming syntax, 13
dumping variable values, 255 VHDL-1987, enabling support for, 276
flushing the buffer contents, 269 VHDL-1993, enabling support for, 276
generating from WLF files, 417 VHDL-2002, enabling support for, 276
inserting comments, 256 VHDL-2008
internal signals, adding, 253 package STANDARD
specifying maximum file size, 270 REAL_VECTOR, 279
specifying name of, 267 VHDL-2008, enabling support for, 276
specifying the file name, 265 vhencrypt command, 299
state mapping, 265, 267 view command, 301
turn off VCD dumping, 271 viewing
turn on VCD dumping, 272 waveforms, 367
viewing files from another tool, 273 virtual count commands, 304
vcd files command, 267 virtual define command, 305
vcd flush command, 269 virtual delete command, 306
vcd limit command, 270 virtual describe command, 307
vcd off command, 271 virtual expand commands, 308
vcd on command, 272 virtual function command, 309
vcd2wlf command, 273 virtual hide command, 312
vcom command, 275 virtual log command, 313
vcom Examples, 286 virtual nohide command, 315
vdel command, 288 virtual nolog command, 316
vdir command, 290 virtual region command, 318
vector elements, initializing, 89 virtual save command, 319
vencrypt command, 293 virtual show command, 320
vendor libraries, compatibility of, 290 virtual signal command, 321
Verilog vlib command, 327
$finish behavior, customizing, 376 vlog
capturing port driver data with -dumpports, multiple file compilation, 337
265 vlog command, 329
Verilog 2001 vmake command, 347
disabling support, 344 vmap command, 349
verror command, 295 vsim
version disabling internal setting of
obtaining with vsim command, 367 LD_LIBRARY_PATH, 359
obtaining with vsim<info> commands, 381 vsim build date and version, 381
vgencomp command, 297 vsim command, 351
VHDL vsim Examples, 379

ModelSim Reference Manual, v10.1c 447

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

—W— WildcardFilter Preference Variable, 18

WARNING[8], -lint argument to vlog, 337 windows
warnings List window
SDF, disabling, 364 output file, 427
suppressing VCOM warning messages, saving the format of, 424
284, 339 opening
suppressing VLOG warning messages, 339 from command line, 301
suppressing VSIM warning messages, 375 Wave window
watch window path elements, changing, 98
add watch command, 59 WLF files
adding items to, 59 collapsing deltas, 368
watching signal values, 59 collapsing time steps, 368
wave commands, 384 converting to VCD, 417
wave create command, 388 creating from VCD, 273
wave cursor commands, 384 indexing, 418
wave edit command, 394 limiting size, 369
wave export command, 397 log command, 156
wave import command, 399 merging, 418
wave log format (WLF) file, 367 optimizing, 418
of binary signal values, 156 optimizing waveform viewing, 369
wave modify command, 400 repairing, 423
wave sort command, 405 saving, 112, 113
Wave window specifying name, 367
adding items to, 60 wlfman command, 418
WaveActivateNextPane command, 425 wlf2log command, 415
waveform editor wlf2vcd command, 417
creating waves, 388 wlfman command, 418
editing commands, 394 wlfrecover command, 423
importing vcd stimulus file, 399 write format command, 424
modifying existing waves, 400 write list command, 427
saving waves, 397 write preferences command, 428
waveform logfile write report command, 429
log command, 156 write timing command, 432
waveforms write transcript command, 434
optimizing viewing of, 369 write tssi command, 435
saving and viewing, 156 write wave command, 437
WaveRestoreCursors command, 425
WaveRestoreZoom command, 425 —X—
X propagation
when command, 406
disabling for entire design, 360
when statement
time-based breakpoints, 412 —Y—
where command, 414 -y, 344
wildcard characters
for pattern matching in simulator —Z—
commands, 17 zoom

448 ModelSim Reference Manual, v10.1c

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

wave window
returning current range, 385

ModelSim Reference Manual, v10.1c 449

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

450 ModelSim Reference Manual, v10.1c

End-User License Agreement
The latest version of the End-User License Agreement is available on-line at:
www.mentor.com/eula

IMPORTANT INFORMATION
USE OF ALL SOFTWARE IS SUBJECT TO LICENSE RESTRICTIONS. CAREFULLY READ THIS LICENSE
AGREEMENT BEFORE USING THE PRODUCTS. USE OF SOFTWARE INDICATES CUSTOMER’S
COMPLETE AND UNCONDITIONAL ACCEPTANCE OF THE TERMS AND CONDITIONS SET FORTH IN
THIS AGREEMENT. ANY ADDITIONAL OR DIFFERENT PURCHASE ORDER TERMS AND CONDITIONS
SHALL NOT APPLY.

END-USER LICENSE AGREEMENT (“Agreement”)

This is a legal agreement concerning the use of Software (as defined in Section 2) and hardware (collectively “Products”)
between the company acquiring the Products (“Customer”), and the Mentor Graphics entity that issued the
corresponding quotation or, if no quotation was issued, the applicable local Mentor Graphics entity (“Mentor
Graphics”). Except for license agreements related to the subject matter of this license agreement which are physically
signed by Customer and an authorized representative of Mentor Graphics, this Agreement and the applicable quotation
contain the parties' entire understanding relating to the subject matter and supersede all prior or contemporaneous
agreements. If Customer does not agree to these terms and conditions, promptly return or, in the case of Software
received electronically, certify destruction of Software and all accompanying items within five days after receipt of
Software and receive a full refund of any license fee paid.

1. ORDERS, FEES AND PAYMENT.

1.1. To the extent Customer (or if agreed by Mentor Graphics, Customer’s appointed third party buying agent) places and
Mentor Graphics accepts purchase orders pursuant to this Agreement (“Order(s)”), each Order will constitute a contract
between Customer and Mentor Graphics, which shall be governed solely and exclusively by the terms and conditions of
this Agreement, any applicable addenda and the applicable quotation, whether or not these documents are referenced on the
Order. Any additional or conflicting terms and conditions appearing on an Order will not be effective unless agreed in
writing by an authorized representative of Customer and Mentor Graphics.
1.2. Amounts invoiced will be paid, in the currency specified on the applicable invoice, within 30 days from the date of such
invoice. Any past due invoices will be subject to the imposition of interest charges in the amount of one and one-half
percent per month or the applicable legal rate currently in effect, whichever is lower. Prices do not include freight,
insurance, customs duties, taxes or other similar charges, which Mentor Graphics will state separately in the applicable
invoice(s). Unless timely provided with a valid certificate of exemption or other evidence that items are not taxable, Mentor
Graphics will invoice Customer for all applicable taxes including, but not limited to, VAT, GST, sales tax and service tax.
Customer will make all payments free and clear of, and without reduction for, any withholding or other taxes; any such
taxes imposed on payments by Customer hereunder will be Customer’s sole responsibility. If Customer appoints a third
party to place purchase orders and/or make payments on Customer’s behalf, Customer shall be liable for payment under
Orders placed by such third party in the event of default.
1.3. All Products are delivered FCA factory (Incoterms 2000), freight prepaid and invoiced to Customer, except Software
delivered electronically, which shall be deemed delivered when made available to Customer for download. Mentor
Graphics retains a security interest in all Products delivered under this Agreement, to secure payment of the purchase price
of such Products, and Customer agrees to sign any documents that Mentor Graphics determines to be necessary or
convenient for use in filing or perfecting such security interest. Mentor Graphics’ delivery of Software by electronic means
is subject to Customer’s provision of both a primary and an alternate e-mail address.

2. GRANT OF LICENSE. The software installed, downloaded, or otherwise acquired by Customer under this Agreement,
including any updates, modifications, revisions, copies, documentation and design data (“Software”) are copyrighted, trade
secret and confidential information of Mentor Graphics or its licensors, who maintain exclusive title to all Software and retain
all rights not expressly granted by this Agreement. Mentor Graphics grants to Customer, subject to payment of applicable
license fees, a nontransferable, nonexclusive license to use Software solely: (a) in machine-readable, object-code form (except
as provided in Subsection 5.2); (b) for Customer’s internal business purposes; (c) for the term of the license; and (d) on the
computer hardware and at the site authorized by Mentor Graphics. A site is restricted to a one-half mile (800 meter) radius.
Customer may have Software temporarily used by an employee for telecommuting purposes from locations other than a
Customer office, such as the employee's residence, an airport or hotel, provided that such employee's primary place of
employment is the site where the Software is authorized for use. Mentor Graphics’ standard policies and programs, which vary
depending on Software, license fees paid or services purchased, apply to the following: (a) relocation of Software; (b) use of
Software, which may be limited, for example, to execution of a single session by a single user on the authorized hardware or for
a restricted period of time (such limitations may be technically implemented through the use of authorization codes or similar
devices); and (c) support services provided, including eligibility to receive telephone support, updates, modifications, and
revisions. For the avoidance of doubt, if Customer requests any change or enhancement to Software, whether in the course of
receiving support or consulting services, evaluating Software, performing beta testing or otherwise, any inventions, product
improvements, modifications or developments made by Mentor Graphics (at Mentor Graphics’ sole discretion) will be the
exclusive property of Mentor Graphics.

3. ESC SOFTWARE. If Customer purchases a license to use development or prototyping tools of Mentor Graphics’ Embedded
Software Channel (“ESC”), Mentor Graphics grants to Customer a nontransferable, nonexclusive license to reproduce and
distribute executable files created using ESC compilers, including the ESC run-time libraries distributed with ESC C and C++
compiler Software that are linked into a composite program as an integral part of Customer’s compiled computer program,
provided that Customer distributes these files only in conjunction with Customer’s compiled computer program. Mentor
Graphics does NOT grant Customer any right to duplicate, incorporate or embed copies of Mentor Graphics’ real-time operating
systems or other embedded software products into Customer’s products or applications without first signing or otherwise
agreeing to a separate agreement with Mentor Graphics for such purpose.

4. BETA CODE.
4.1. Portions or all of certain Software may contain code for experimental testing and evaluation (“Beta Code”), which may not
be used without Mentor Graphics’ explicit authorization. Upon Mentor Graphics’ authorization, Mentor Graphics grants to
Customer a temporary, nontransferable, nonexclusive license for experimental use to test and evaluate the Beta Code
without charge for a limited period of time specified by Mentor Graphics. This grant and Customer’s use of the Beta Code
shall not be construed as marketing or offering to sell a license to the Beta Code, which Mentor Graphics may choose not to
release commercially in any form.
4.2. If Mentor Graphics authorizes Customer to use the Beta Code, Customer agrees to evaluate and test the Beta Code under
normal conditions as directed by Mentor Graphics. Customer will contact Mentor Graphics periodically during Customer’s
use of the Beta Code to discuss any malfunctions or suggested improvements. Upon completion of Customer’s evaluation
and testing, Customer will send to Mentor Graphics a written evaluation of the Beta Code, including its strengths,
weaknesses and recommended improvements.
4.3. Customer agrees to maintain Beta Code in confidence and shall restrict access to the Beta Code, including the methods and
concepts utilized therein, solely to those employees and Customer location(s) authorized by Mentor Graphics to perform
beta testing. Customer agrees that any written evaluations and all inventions, product improvements, modifications or
developments that Mentor Graphics conceived or made during or subsequent to this Agreement, including those based
partly or wholly on Customer’s feedback, will be the exclusive property of Mentor Graphics. Mentor Graphics will have
exclusive rights, title and interest in all such property. The provisions of this Subsection 4.3 shall survive termination of
this Agreement.

5. RESTRICTIONS ON USE.
5.1. Customer may copy Software only as reasonably necessary to support the authorized use. Each copy must include all
notices and legends embedded in Software and affixed to its medium and container as received from Mentor Graphics. All
copies shall remain the property of Mentor Graphics or its licensors. Customer shall maintain a record of the number and
primary location of all copies of Software, including copies merged with other software, and shall make those records
available to Mentor Graphics upon request. Customer shall not make Products available in any form to any person other
than Customer’s employees and on-site contractors, excluding Mentor Graphics competitors, whose job performance
requires access and who are under obligations of confidentiality. Customer shall take appropriate action to protect the
confidentiality of Products and ensure that any person permitted access does not disclose or use it except as permitted by
this Agreement. Customer shall give Mentor Graphics written notice of any unauthorized disclosure or use of the Products
as soon as Customer learns or becomes aware of such unauthorized disclosure or use. Except as otherwise permitted for
purposes of interoperability as specified by applicable and mandatory local law, Customer shall not reverse-assemble,
reverse-compile, reverse-engineer or in any way derive any source code from Software. Log files, data files, rule files and
script files generated by or for the Software (collectively “Files”), including without limitation files containing Standard
Verification Rule Format (“SVRF”) and Tcl Verification Format (“TVF”) which are Mentor Graphics’ proprietary
syntaxes for expressing process rules, constitute or include confidential information of Mentor Graphics. Customer may
share Files with third parties, excluding Mentor Graphics competitors, provided that the confidentiality of such Files is
protected by written agreement at least as well as Customer protects other information of a similar nature or importance,
but in any case with at least reasonable care. Customer may use Files containing SVRF or TVF only with Mentor Graphics
products. Under no circumstances shall Customer use Software or Files or allow their use for the purpose of developing,
enhancing or marketing any product that is in any way competitive with Software, or disclose to any third party the results
of, or information pertaining to, any benchmark.
5.2. If any Software or portions thereof are provided in source code form, Customer will use the source code only to correct
software errors and enhance or modify the Software for the authorized use. Customer shall not disclose or permit disclosure
of source code, in whole or in part, including any of its methods or concepts, to anyone except Customer’s employees or
contractors, excluding Mentor Graphics competitors, with a need to know. Customer shall not copy or compile source code
in any manner except to support this authorized use.
5.3. Customer may not assign this Agreement or the rights and duties under it, or relocate, sublicense or otherwise transfer the
Products, whether by operation of law or otherwise (“Attempted Transfer”), without Mentor Graphics’ prior written
consent and payment of Mentor Graphics’ then-current applicable relocation and/or transfer fees. Any Attempted Transfer
without Mentor Graphics’ prior written consent shall be a material breach of this Agreement and may, at Mentor Graphics’
option, result in the immediate termination of the Agreement and/or the licenses granted under this Agreement. The terms
of this Agreement, including without limitation the licensing and assignment provisions, shall be binding upon Customer’s
permitted successors in interest and assigns.
5.4. The provisions of this Section 5 shall survive the termination of this Agreement.

6. SUPPORT SERVICES. To the extent Customer purchases support services, Mentor Graphics will provide Customer updates
and technical support for the Products, at the Customer site(s) for which support is purchased, in accordance with Mentor
Graphics’ then current End-User Support Terms located at http://supportnet.mentor.com/about/legal/.

7. AUTOMATIC CHECK FOR UPDATES; PRIVACY. Technological measures in Software may communicate with servers
of Mentor Graphics or its contractors for the purpose of checking for and notifying the user of updates and to ensure that the
Software in use is licensed in compliance with this Agreement. Mentor Graphics will not collect any personally identifiable data
in this process and will not disclose any data collected to any third party without the prior written consent of Customer, except to
Mentor Graphics’ outside attorneys or as may be required by a court of competent jurisdiction.

8. LIMITED WARRANTY.
8.1. Mentor Graphics warrants that during the warranty period its standard, generally supported Products, when properly
installed, will substantially conform to the functional specifications set forth in the applicable user manual. Mentor
Graphics does not warrant that Products will meet Customer’s requirements or that operation of Products will be
uninterrupted or error free. The warranty period is 90 days starting on the 15th day after delivery or upon installation,
whichever first occurs. Customer must notify Mentor Graphics in writing of any nonconformity within the warranty period.
For the avoidance of doubt, this warranty applies only to the initial shipment of Software under an Order and does not
renew or reset, for example, with the delivery of (a) Software updates or (b) authorization codes or alternate Software under
a transaction involving Software re-mix. This warranty shall not be valid if Products have been subject to misuse,
unauthorized modification or improper installation. MENTOR GRAPHICS’ ENTIRE LIABILITY AND CUSTOMER’S
EXCLUSIVE REMEDY SHALL BE, AT MENTOR GRAPHICS’ OPTION, EITHER (A) REFUND OF THE PRICE
PAID UPON RETURN OF THE PRODUCTS TO MENTOR GRAPHICS OR (B) MODIFICATION OR
REPLACEMENT OF THE PRODUCTS THAT DO NOT MEET THIS LIMITED WARRANTY, PROVIDED
CUSTOMER HAS OTHERWISE COMPLIED WITH THIS AGREEMENT. MENTOR GRAPHICS MAKES NO
WARRANTIES WITH RESPECT TO: (A) SERVICES; (B) PRODUCTS PROVIDED AT NO CHARGE; OR (C) BETA
CODE; ALL OF WHICH ARE PROVIDED “AS IS.”
8.2. THE WARRANTIES SET FORTH IN THIS SECTION 8 ARE EXCLUSIVE. NEITHER MENTOR GRAPHICS NOR
ITS LICENSORS MAKE ANY OTHER WARRANTIES EXPRESS, IMPLIED OR STATUTORY, WITH RESPECT TO
PRODUCTS PROVIDED UNDER THIS AGREEMENT. MENTOR GRAPHICS AND ITS LICENSORS
SPECIFICALLY DISCLAIM ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NON-INFRINGEMENT OF INTELLECTUAL PROPERTY.

9. LIMITATION OF LIABILITY. EXCEPT WHERE THIS EXCLUSION OR RESTRICTION OF LIABILITY WOULD BE

VOID OR INEFFECTIVE UNDER APPLICABLE LAW, IN NO EVENT SHALL MENTOR GRAPHICS OR ITS
LICENSORS BE LIABLE FOR INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES (INCLUDING
LOST PROFITS OR SAVINGS) WHETHER BASED ON CONTRACT, TORT OR ANY OTHER LEGAL THEORY, EVEN
IF MENTOR GRAPHICS OR ITS LICENSORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. IN
NO EVENT SHALL MENTOR GRAPHICS’ OR ITS LICENSORS’ LIABILITY UNDER THIS AGREEMENT EXCEED
THE AMOUNT RECEIVED FROM CUSTOMER FOR THE HARDWARE, SOFTWARE LICENSE OR SERVICE GIVING
RISE TO THE CLAIM. IN THE CASE WHERE NO AMOUNT WAS PAID, MENTOR GRAPHICS AND ITS LICENSORS
SHALL HAVE NO LIABILITY FOR ANY DAMAGES WHATSOEVER. THE PROVISIONS OF THIS SECTION 9 SHALL
SURVIVE THE TERMINATION OF THIS AGREEMENT.

10. HAZARDOUS APPLICATIONS. CUSTOMER ACKNOWLEDGES IT IS SOLELY RESPONSIBLE FOR TESTING ITS
PRODUCTS USED IN APPLICATIONS WHERE THE FAILURE OR INACCURACY OF ITS PRODUCTS MIGHT
RESULT IN DEATH OR PERSONAL INJURY (“HAZARDOUS APPLICATIONS”). NEITHER MENTOR GRAPHICS
NOR ITS LICENSORS SHALL BE LIABLE FOR ANY DAMAGES RESULTING FROM OR IN CONNECTION WITH
THE USE OF MENTOR GRAPHICS PRODUCTS IN OR FOR HAZARDOUS APPLICATIONS. THE PROVISIONS OF
THIS SECTION 10 SHALL SURVIVE THE TERMINATION OF THIS AGREEMENT.

11. INDEMNIFICATION. CUSTOMER AGREES TO INDEMNIFY AND HOLD HARMLESS MENTOR GRAPHICS AND
ITS LICENSORS FROM ANY CLAIMS, LOSS, COST, DAMAGE, EXPENSE OR LIABILITY, INCLUDING
ATTORNEYS’ FEES, ARISING OUT OF OR IN CONNECTION WITH THE USE OF PRODUCTS AS DESCRIBED IN
SECTION 10. THE PROVISIONS OF THIS SECTION 11 SHALL SURVIVE THE TERMINATION OF THIS
AGREEMENT.

12. INFRINGEMENT.
12.1. Mentor Graphics will defend or settle, at its option and expense, any action brought against Customer in the United States,
Canada, Japan, or member state of the European Union which alleges that any standard, generally supported Product
acquired by Customer hereunder infringes a patent or copyright or misappropriates a trade secret in such jurisdiction.
Mentor Graphics will pay costs and damages finally awarded against Customer that are attributable to the action. Customer
understands and agrees that as conditions to Mentor Graphics’ obligations under this section Customer must: (a) notify
Mentor Graphics promptly in writing of the action; (b) provide Mentor Graphics all reasonable information and assistance
to settle or defend the action; and (c) grant Mentor Graphics sole authority and control of the defense or settlement of the
action.
12.2. If a claim is made under Subsection 12.1 Mentor Graphics may, at its option and expense, (a) replace or modify the Product
so that it becomes noninfringing; (b) procure for Customer the right to continue using the Product; or (c) require the return
of the Product and refund to Customer any purchase price or license fee paid, less a reasonable allowance for use.
12.3. Mentor Graphics has no liability to Customer if the action is based upon: (a) the combination of Software or hardware with
any product not furnished by Mentor Graphics; (b) the modification of the Product other than by Mentor Graphics; (c) the
use of other than a current unaltered release of Software; (d) the use of the Product as part of an infringing process; (e) a
product that Customer makes, uses, or sells; (f) any Beta Code or Product provided at no charge; (g) any software provided
by Mentor Graphics’ licensors who do not provide such indemnification to Mentor Graphics’ customers; or
(h) infringement by Customer that is deemed willful. In the case of (h), Customer shall reimburse Mentor Graphics for its
reasonable attorney fees and other costs related to the action.
12.4. THIS SECTION 12 IS SUBJECT TO SECTION 9 ABOVE AND STATES THE ENTIRE LIABILITY OF MENTOR
GRAPHICS AND ITS LICENSORS FOR DEFENSE, SETTLEMENT AND DAMAGES, AND CUSTOMER’S SOLE
AND EXCLUSIVE REMEDY, WITH RESPECT TO ANY ALLEGED PATENT OR COPYRIGHT INFRINGEMENT
OR TRADE SECRET MISAPPROPRIATION BY ANY PRODUCT PROVIDED UNDER THIS AGREEMENT.

13. TERMINATION AND EFFECT OF TERMINATION. If a Software license was provided for limited term use, such license
will automatically terminate at the end of the authorized term.
13.1. Mentor Graphics may terminate this Agreement and/or any license granted under this Agreement immediately upon written
notice if Customer: (a) exceeds the scope of the license or otherwise fails to comply with the licensing or confidentiality
provisions of this Agreement, or (b) becomes insolvent, files a bankruptcy petition, institutes proceedings for liquidation or
winding up or enters into an agreement to assign its assets for the benefit of creditors. For any other material breach of any
provision of this Agreement, Mentor Graphics may terminate this Agreement and/or any license granted under this
Agreement upon 30 days written notice if Customer fails to cure the breach within the 30 day notice period. Termination of
this Agreement or any license granted hereunder will not affect Customer’s obligation to pay for Products shipped or
licenses granted prior to the termination, which amounts shall be payable immediately upon the date of termination.
13.2. Upon termination of this Agreement, the rights and obligations of the parties shall cease except as expressly set forth in this
Agreement. Upon termination, Customer shall ensure that all use of the affected Products ceases, and shall return hardware
and either return to Mentor Graphics or destroy Software in Customer’s possession, including all copies and
documentation, and certify in writing to Mentor Graphics within ten business days of the termination date that Customer no
longer possesses any of the affected Products or copies of Software in any form.

14. EXPORT. The Products provided hereunder are subject to regulation by local laws and United States government agencies,
which prohibit export or diversion of certain products and information about the products to certain countries and certain
persons. Customer agrees that it will not export Products in any manner without first obtaining all necessary approval from
appropriate local and United States government agencies.

15. U.S. GOVERNMENT LICENSE RIGHTS. Software was developed entirely at private expense. All Software is commercial
computer software within the meaning of the applicable acquisition regulations. Accordingly, pursuant to US FAR 48 CFR
12.212 and DFAR 48 CFR 227.7202, use, duplication and disclosure of the Software by or for the U.S. Government or a U.S.
Government subcontractor is subject solely to the terms and conditions set forth in this Agreement, except for provisions which
are contrary to applicable mandatory federal laws.

16. THIRD PARTY BENEFICIARY. Mentor Graphics Corporation, Mentor Graphics (Ireland) Limited, Microsoft Corporation
and other licensors may be third party beneficiaries of this Agreement with the right to enforce the obligations set forth herein.

17. REVIEW OF LICENSE USAGE. Customer will monitor the access to and use of Software. With prior written notice and
during Customer’s normal business hours, Mentor Graphics may engage an internationally recognized accounting firm to
review Customer’s software monitoring system and records deemed relevant by the internationally recognized accounting firm
to confirm Customer’s compliance with the terms of this Agreement or U.S. or other local export laws. Such review may include
FLEXlm or FLEXnet (or successor product) report log files that Customer shall capture and provide at Mentor Graphics’
request. Customer shall make records available in electronic format and shall fully cooperate with data gathering to support the
license review. Mentor Graphics shall bear the expense of any such review unless a material non-compliance is revealed. Mentor
Graphics shall treat as confidential information all information gained as a result of any request or review and shall only use or
disclose such information as required by law or to enforce its rights under this Agreement. The provisions of this Section 17
shall survive the termination of this Agreement.

18. CONTROLLING LAW, JURISDICTION AND DISPUTE RESOLUTION. The owners of certain Mentor Graphics
intellectual property licensed under this Agreement are located in Ireland and the United States. To promote consistency around
the world, disputes shall be resolved as follows: excluding conflict of laws rules, this Agreement shall be governed by and
construed under the laws of the State of Oregon, USA, if Customer is located in North or South America, and the laws of Ireland
if Customer is located outside of North or South America. All disputes arising out of or in relation to this Agreement shall be
submitted to the exclusive jurisdiction of the courts of Portland, Oregon when the laws of Oregon apply, or Dublin, Ireland when
the laws of Ireland apply. Notwithstanding the foregoing, all disputes in Asia arising out of or in relation to this Agreement shall
be resolved by arbitration in Singapore before a single arbitrator to be appointed by the chairman of the Singapore International
Arbitration Centre (“SIAC”) to be conducted in the English language, in accordance with the Arbitration Rules of the SIAC in
effect at the time of the dispute, which rules are deemed to be incorporated by reference in this section. This section shall not
restrict Mentor Graphics’ right to bring an action against Customer in the jurisdiction where Customer’s place of business is
located. The United Nations Convention on Contracts for the International Sale of Goods does not apply to this Agreement.

19. SEVERABILITY. If any provision of this Agreement is held by a court of competent jurisdiction to be void, invalid,
unenforceable or illegal, such provision shall be severed from this Agreement and the remaining provisions will remain in full
force and effect.

20. MISCELLANEOUS. This Agreement contains the parties’ entire understanding relating to its subject matter and supersedes all
prior or contemporaneous agreements, including but not limited to any purchase order terms and conditions. Some Software
may contain code distributed under a third party license agreement that may provide additional rights to Customer. Please see
the applicable Software documentation for details. This Agreement may only be modified in writing by authorized
representatives of the parties. Waiver of terms or excuse of breach must be in writing and shall not constitute subsequent
consent, waiver or excuse.

Rev. 100615, Part No. 246066