User guide

14-8
Negative Timing Checks
The following additional arguments are optional:
timestamp_cond
This argument specifies the condition which determines whether
or not VCS reports a timing violation.
In the setup phase of a $setuphold timing check, VCS records
or “stamps” the time of a data event internally so that when a
reference event occurs, it can compare the times of these events
to see if there is a setup timing violation. If the condition specified
by this argument is false, VCS does not record or “stamp” the data
event so there cannot be a setup timing violation.
Similarly, in the hold phase of a $setuphold timing check, VCS
records or “stamps” the time of a reference event internally so that
when a data event occurs it can compare the times of these events
to see if there is a hold timing violation. If the condition specified
by this argument is false, VCS does not record or “stamp” the
reference event so there cannot be a hold timing violation.
timecheck_cond
This argument specifies the condition which determines whether
or not VCS reports a timing violation.
In the setup phase of a $setuphold timing check, VCS
compares or “checks” the time of the reference event with the time
of the data event to see if there is a setup timing violation. If the
condition specified by this argument is false, VCS does not make
this comparison and so there is no setup timing violation.
Similarly, in the hold phase of a $setuphold timing check, VCS
compares or “checks” the time of a data event with the time of a
reference event to see if there is a hold timing violation. If the
condition specified by this argument is false, VCS does not make
this comparison and so there is no hold timing violation.
delayed_reference_signal
The name of the delayed version of the reference signal.