User guide

D-41
Compiler Directives and System Tasks
Saving and Restarting The Simulation State
$save
Saves the current simulation state in a file.
See IEEE std 1364-2001 pages 742-743, also see “Save and
Restart” on page -4-4.
$restart
Restores the simulation to the state that you saved in the check
file with the $save system task. Enter this system task at the CLI
prompt instead of in the source code. You can also do this by
entering the name of the check file at the system prompt. See
IEEE std 1364-2001 pages 742-743; also see “Save and Restart”
on page -4-4.
Checking for X and Z Values in Conditional Expressions
$xzcheckon
Displays a warning message every time VCS evaluates a
conditional expression to have an X or Z value.
Syntax:
$xzcheckon(hierarchical_name,level_number)
hierarchical_name
Hierarchical name of the module instance, that is, the top-level
instance of the subhierarchy for which you want to enable
checking.
level_number
Number of levels down in the subhierarchy from the specified
module instance. Checking is also enabled for the instances on
these levels.