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really dumb code for converting a PAL file into verilog
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#!/usr/bin/env python3 | |
import sys | |
import re | |
palfile = [ x.strip() for x in open(sys.argv[1]).readlines() ] | |
part = palfile[0] | |
reference = palfile[1] | |
checksum = palfile[2] | |
description = palfile[3] | |
pins = palfile[4].split() + palfile[5].split() | |
def decomposepin(pin): | |
if pin.startswith("/"): | |
return (pin[1:], True) | |
else: | |
return (pin, False) | |
def composepin(pin, al): | |
if al: | |
return pin+"_n" | |
else: | |
return pin | |
def verilogsafe(s): | |
return re.sub("\W","_", s) | |
pins_by_name = { } | |
for (pin, id) in zip(pins, range(1, 100)): | |
name, al = decomposepin(pin) | |
pins_by_name[name] = { "id": id, | |
"name": name, | |
"al": al } | |
signals = { } | |
current = None | |
for line in palfile[7:]: | |
l = re.sub("\s+;.+", "", line) | |
if "=" in l: | |
# starting a new signal | |
m = re.match("\s*(\S+)\s*=\s*(.+)", l) | |
current, al = decomposepin(m.group(1)) | |
signals.setdefault(current, { "al": al, | |
"eq": [ ] })["eq"].append(m.group(2)) | |
if l.startswith("+"): | |
if current is None: | |
raise Exception("no in-progress signal") | |
# continuing the same signal | |
signals[current]["eq"].append(l[1:].strip()) | |
for pinname in pins_by_name: | |
if pinname in signals: | |
pins_by_name[pinname]['dir'] = 'output' | |
else: | |
pins_by_name[pinname]['dir'] = 'input' | |
vpins = [ ] | |
for pinname in sorted(pins_by_name, key=lambda p: pins_by_name[p]['id']): | |
if pinname in ('GND', 'VCC'): | |
continue | |
pininf = pins_by_name[pinname] | |
name = pinname | |
if pininf['al']: | |
name += "_n" | |
vpins.append(f"{pininf['dir']} {verilogsafe(name)}") | |
vpins = ", ".join(vpins) | |
print(f"module {verilogsafe(reference)}({vpins});") | |
for pinname in sorted(pins_by_name, key=lambda p: pins_by_name[p]['id']): | |
pininf = pins_by_name[pinname] | |
print(f"// {pininf['id']:2d} {'/' if pininf['al'] else ''}{pininf['name']}") | |
print() | |
def fixupterm(term): | |
rawvariables = [ x.strip() for x in term.split("*") ] | |
variables = [ ] | |
for var in rawvariables: | |
name, al = decomposepin(var) | |
if pins_by_name[name]['al'] == al: | |
# polarity match | |
variables.append(composepin(verilogsafe(name), pins_by_name[name]['al'])) | |
else: | |
# mismatch | |
variables.append("~"+composepin(verilogsafe(name), pins_by_name[name]['al'])) | |
return "("+(" & ".join(variables))+")" | |
for name in signals: | |
siginf = signals[name] | |
pininf = pins_by_name[name] | |
body = signals[name]['eq'] | |
body = " | ".join([ fixupterm(x) for x in body ]) | |
if pininf['al'] == siginf['al']: | |
# polarity matches | |
print(f"assign {composepin(name, pininf['al'])} = {body};") | |
else: | |
# polarity mismatch | |
print(f"assign {composepin(name, pininf['al'])} = ~({body});") | |
print() | |
print("endmodule") |
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