Author image Yichun Zhang (章亦春)


ModelSim::List - Analyse the 'list' output of the ModelSim simulator


This document describes ModelSim::List 0.06 released on 2 June, 2007.


    use ModelSim::List;
    $list = ModelSim::List->new;

    # ram.lst is generated by ModelSim
    # simulator (via the "write list" command)
    $list->parse('ram.lst') or
        die $list->error();

    # get the value of signal /ram/address at time 100:
    $value = $list->strobe('/ram/address', 100);

    # get the time when signal /alu/rdy get the value 1:
    $time = $list->time_of('/alu/rdy', 1);

    # specify regex rather than actual value:
    $time = $list->time_of('/processor/bus_data', qr/^z+$/i);

    $time = $list->time_of($signal, $value, $start_time);
    $time = $list->time_of($signal, $value, $start_time, $end_time);
    die $list->error() unless defined $time;


This module provides a class named ModelSim::List with which the EDA tester can easily check in the signals contained in the files generated by ModelSim's "write list" command in a programming manner.


$list = ModelSim::List->new()

This is the constructor of the ModelSim::List class.


This method gets the object parse the list file specified as $file_name. You can invoke the parse method on the same object several times. Once you specify a list file, the new file will override the old one completely. No matter whether you use an -event option in your "write list" command to generate the file or not, the object will recognize the list format automatically.

I'd like to give one example for each of the two file format here:

         ns       /ram/mfc
          delta       /ram/bus_data
          0  +2          1 xxxxxxxx
          0  +3          0 zzzzzzzz
         10  +0          1 0000aaaa
         10  +1          0 0000abcd
         29  +0          1 0000abcd
         38  +0          0 0000abcd
         38  +2          0 zzzzzzzz
         86  +0          1 zzzzzzzz
         86  +1          1 0000abcd

and if you use the -event option in the "write list" command, the list file will like follows:

    @0 +0
    /ram/mfc x
    /ram/mfc 0
    /ram/bus_data zzzzzzzz
    /ram/bus_data zzzzzzzz
    @10 +0
    /ram/bus_data 0000abcd
    @29 +0
    /ram/mfc 1
    @38 +0
    /ram/mfc 0
    @38 +2

The method returns 1 to indicate success. When it returns undef, it is recommended to check the error info via the error() method.


Returns the error message for the last failed operation.

$list->strobe($signal, $time)

The strobe method are used to get the value of a signal named $signal at any given time instant, $time. The object will preserve the original signal value format used in the list file. No format conversion will happen.

When strobe() returns undef, it is recommended to check the detailed info via the error() method if you feel surprised.

CAUTION: The delta number will be totally ignored. Therefore, if signal /module/a becomes 0 at "0 ns +0", and changes to 1 at "0 ns +1", thus $obj->strobe('/module/a', 0) will return 1 rather than 0.

$list->time_of($signal, $value, ?$start, ?$end)

You can utilize the time_of method to get the time instant when $signal first gained the value $value within the time interval specified by $tart and $end. Both the last two arguments are optional. In the case that $start is missing, the initial time 0 will be assumed. If the signal fails to achieve $value, time_of will return undef.

If the $value argument is a regex ref, time_of will perform pattern matching instead of string comparing.

When time_of() returns undef, it is recommended to check the detailed info via the error() method if you feel surprised.


You can always get the latest source from the following Subversion repository:

which has anonymous access to all.

If you do want a commit bit, please let me know.


There must be some serious bugs lurking somewhere. If you find one, please consider firing off a report to


I use Devel::Cover to test the code coverage of this module and here is the report:

 ---------------------------- ------ ------ ------ ------ ------ ------ ------
 File                           stmt   bran   cond    sub    pod   time  total
 ---------------------------- ------ ------ ------ ------ ------ ------ ------
 blib/lib/ModelSim/      89.4   82.8   77.8   91.7   40.0   99.7   85.0
 ---------------------------- ------ ------ ------ ------ ------ ------ ------


Agent Zhang (<>)


Copyright (C) 2005-2007 by Agent Zhang. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


ModelSim Command Reference