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corelogic: timeline module

This commit is contained in:
Sebastien Bourdeauducq 2011-12-11 01:11:13 +01:00
parent 019ef16db4
commit af74a89b8a
1 changed files with 33 additions and 0 deletions
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33
migen/corelogic/timeline.py Normal file
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from migen.fhdl import structure as f
class Inst:
def __init__(self, trigger, events):
self.trigger = trigger
self.events = events
self.lastevent = max([e[0] for e in events] + [e[2] for e in events if len(e) == 3])
f.Declare(self, "_counter", f.BV(f.BitsFor(self.lastevent)))
def GetFragment(self):
counterlogic = f.If(self._counter != f.Constant(0, self._counter.bv),
[f.Assign(self._counter, self._counter + f.Constant(1, self._counter.bv))],
[f.If(self.trigger, [f.Assign(self._counter, f.Constant(1, self._counter.bv))])])
# insert counter reset if it doesn't automatically overflow
# (test if self.lastevent+1 is a power of 2)
if (self.lastevent & (self.lastevent + 1)) != 0:
counterlogic = f.If(self._counter == self.lastevent,
[f.Assign(self._counter, f.Constant(0, self._counter.bv))],
[counterlogic])
def getcond(e):
if len(e) == 3:
if e[0] == 0:
return self.trigger & (self._counter <= f.Constant(e[2], self._counter.bv))
else:
return (self._counter >= f.Constant(e[0], self._counter.bv)) & (self._counter <= f.Constant(e[2], self._counter.bv))
else:
if e[0] == 0:
return self.trigger
else:
return self._counter == f.Constant(e[0], self._counter.bv)
sync = [f.If(getcond(e), e[1]) for e in self.events]
sync.append(counterlogic)
return f.Fragment(sync=sync)