A python grepper script to split / select / filter VCD signals

[sdaau]

Hi everyone,

Apologies for cross-posting - just wanted to post about this, since I
had trouble finding something similar elsewhere.


The GHDL webpage currently says:

http://ghdl.free.fr/ghdl/Simulation-options.html

Currently, there is no way to select signals to be dumped:
all signals are dumped, which can generate big files.

.... and as I didn't have much luck finding existing VCD signal
"splitters" (that would isolate a signal from a bundle), here's my
attempt at a python script that will act as a "grepper" for vcd
signals:

http://sdaaubckp.svn.sourceforge.net/viewvc/sdaaubckp/single-scripts/vcd-sig-grep.py?view=markup


As always, the usual YMMV applies For myself, the script was tested
under python 2.7 (which seems slightly faster) and 3.2 on Ubuntu 11.04
Linux, and should work with piping to stdin - I have pretty much
tested it only with GHDL output, as in:

ghdl -r test_workbench --stop-time=20000us --vcd=/dev/stdout |
python2.7 vcd-sig-grep.py --sigs="signal1,signal2" > tmpout.vcd


.... and for test workbench, I've just used the file/approach here:

SourceForge.net: ngspice: VHDL sim'd .vcd data - as analog sim source
-
http://sourceforge.net/projects/ngspice/forums/forum/133842/topic/4839104

Note there is no special handling of '$dumpvars' and such (however,
GHDL seems not to output them anyways)... I've tested the .vcd output
with gtkwave only, seems to be read in fine.


Well, if there's a similar tool that I obviously missed (apart from
gtkwave used with a tcl script, which is used in the above ngspice-
users entry), I sure would like to know about it.

Otherwise, I hope the community may find this useful...

Cheers!