davebv / pyvcd

Python package for writing Value Change Dump (VCD) files.

PyVCD

The PyVCD package writes Value Change Dump (VCD) files as specified in IEEE 1364-2005.

Read the documentation.

Visit PyVCD on GitHub.

Quick Start

>>> import sys
>>> from vcd import VCDWriter
>>> with VCDWriter(sys.stdout, timescale='1 ns', date='today') as writer:
...     counter_var = writer.register_var('a.b.c', 'counter', 'integer', size=8)
...     for timestamp, value in enumerate(range(10, 20, 2)):
...         writer.change(counter_var, timestamp, value)
$date today $end
$timescale 1 ns $end
$scope module a $end
$scope module b $end
$scope module c $end
$var integer 8 0 counter $end
$upscope $end
$upscope $end
$upscope $end
$enddefinitions $end
#0
$dumpvars
b1010 0
$end
#1
b1100 0
#2
b1110 0
#3
b10000 0
#4
b10010 0