User guide

11-12
Race Detection
Method 2: If the Number of Unique Races is Large
If there are many lines in the race.unique.out file then there are a
large number of unique race conditions. If so, one method of finding
the critical race conditions is to do the following:
1. Look in the output file from the vcdiff utility for the simulation time
of the first difference in simulation values.
2. Post process the race.out file looking for races at the time of the
first simulation value difference. Specify simulation times just
before and just after the time of these differences with the
-minmax option. Enter:
PostRace.pl -minmax time time2
3. For each signal in the resulting race.out.post file:
a. If the simulation values differ in the two simulations, then the
race condition in the race.out.post file is a critical race condition.
b. If the simulation values are not different, check the signals that
are assigned the value of this signal or assigned expressions
that include this signal. If the values of these other signals are
different then the race condition in the race.out.post file is a
critical race condition.
Method 3: An Alternative When the Number of Unique Race
Conditions is Large
1. Look in the output file from the vcdiff utility for the simulation time
of the first difference in simulation values.
2. For each signal that has a difference at this simulation time:
a. Traverse the signal dependency backwards in the design until
you find a signal whose values are the same in both simulations.