34 lines
1.3 KiB
Python
34 lines
1.3 KiB
Python
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from migen.fhdl import structure as f
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class Inst:
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def __init__(self, trigger, events):
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self.trigger = trigger
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self.events = events
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self.lastevent = max([e[0] for e in events] + [e[2] for e in events if len(e) == 3])
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f.Declare(self, "_counter", f.BV(f.BitsFor(self.lastevent)))
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def GetFragment(self):
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counterlogic = f.If(self._counter != f.Constant(0, self._counter.bv),
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[f.Assign(self._counter, self._counter + f.Constant(1, self._counter.bv))],
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[f.If(self.trigger, [f.Assign(self._counter, f.Constant(1, self._counter.bv))])])
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# insert counter reset if it doesn't automatically overflow
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# (test if self.lastevent+1 is a power of 2)
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if (self.lastevent & (self.lastevent + 1)) != 0:
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counterlogic = f.If(self._counter == self.lastevent,
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[f.Assign(self._counter, f.Constant(0, self._counter.bv))],
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[counterlogic])
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def getcond(e):
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if len(e) == 3:
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if e[0] == 0:
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return self.trigger & (self._counter <= f.Constant(e[2], self._counter.bv))
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else:
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return (self._counter >= f.Constant(e[0], self._counter.bv)) & (self._counter <= f.Constant(e[2], self._counter.bv))
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else:
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if e[0] == 0:
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return self.trigger
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else:
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return self._counter == f.Constant(e[0], self._counter.bv)
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sync = [f.If(getcond(e), e[1]) for e in self.events]
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sync.append(counterlogic)
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return f.Fragment(sync=sync)
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