User guide

7-4

VCD and VPD File Utilities

Some back-end tools from other vendors fail when you input such a

VCD file. You can use the vcdpost utility to create an alternative VCD

file in which the identifier codes for all nets and registers, including

the ones without value changes, are unique. For example:

$var wire 1 ! ramsel_0_0 $end

$var wire 1 " ramsel_0_1 $end

$var wire 1 # ramsel_1_0 $end

$var wire 1 $ ramsel_1_1 $end

The vcdpost Utility Syntax

The syntax for the vcdpost utility is as follows:

vcdpost [+scalar] [+unique] input_VCD_file output_VCD_file

Here:

+scalar

Specifies creating separate $var sections for each bit in a vector

signal. This option is the default option and you include it on the

command line when you also include the +unique option and

want to create a VCD file that both scalarizes the vector nets and

uniquifies the identifier codes.

+unique

Specifies uniquifying the identifier codes. When you include this

option without the +scalar option, vcdpost uniquifies the

identifier codes without scalarizing the vector signals.

input_VCD_file

The name of the VCD file created by VCS.

output_VCD_file

The name of the alternative VCD file created by the vcdpost utility.