User guide

7-12
VCD and VPD File Utilities
-showmasters (VCD, EVCD files only)
Shows collapsed net masters. VCS can split a collapsed net into
several sub-nets when this has a performance benefit. This option
reports the master signals when the master signals (first signal
defined on a net) are different in the two dump files.
-limitdiffs number_of_diffs
By default, vcdiff stops after the first 50 diffs are reported. This
option overrides that default. Setting this value to 0 causes vcdiff
to report all diffs.
-geninclude filename
Produces a separate file of the given name in addition to the
standard vcdiff output. This file contains a list of signals that have
at least one value change difference. The format of the file is one
signal per line. Each signal name is a full path name. You can use
this file as input to the vcat tool with vcat’s -include option.
-spikes
A spike is defined as a signal that changes multiple times in a
single time step. This option annotates with #’s the value change
differences detected when the signal spikes (glitches). It keeps
and reports a total count of such diffs.
The vcat Utility
The format of a VCD or a EVCD file, although a text file, is written to
be read by software and not by human designers. VCS includes the
vcat utility to enable you to more easily understand the information
contained in a VCD file.