70 lines
1.5 KiB
Python
70 lines
1.5 KiB
Python
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from migen.fhdl.structure import *
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from migen.fhdl.specials import Special
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from migen.fhdl.tools import value_bits_sign, list_signals
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class MultiRegImpl:
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def __init__(self, i, idomain, o, odomain, n):
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self.i = i
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self.idomain = idomain
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self.o = o
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self.odomain = odomain
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w, signed = value_bits_sign(self.i)
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self.regs = [Signal((w, signed)) for i in range(n)]
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def get_fragment(self):
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src = self.i
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o_sync = []
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for reg in self.regs:
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o_sync.append(reg.eq(src))
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src = reg
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comb = [
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self.o.eq(src)
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]
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return Fragment(comb, {self.odomain: o_sync})
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class MultiReg(Special):
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def __init__(self, i, idomain, o, odomain, n=2):
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Special.__init__(self)
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self.i = i
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self.idomain = idomain
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self.o = o
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self.odomain = odomain
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self.n = n
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def list_ios(self, ins, outs, inouts):
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r = set()
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if ins:
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r.update(list_signals(self.i))
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if outs:
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r.update(list_signals(self.o))
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return r
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@staticmethod
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def lower(dr):
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return MultiRegImpl(dr.i, dr.idomain, dr.o, dr.odomain, dr.n)
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class PulseSynchronizer:
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def __init__(self, idomain, odomain):
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self.idomain = idomain
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self.odomain = odomain
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self.i = Signal()
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self.o = Signal()
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def get_fragment(self):
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toggle_i = Signal()
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toggle_o = Signal()
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toggle_o_r = Signal()
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sync_i = [
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If(self.i, toggle_i.eq(~toggle_i))
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]
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sync_o = [
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toggle_o_r.eq(toggle_o)
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]
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comb = [
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self.o.eq(toggle_o ^ toggle_o_r)
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]
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return Fragment(comb,
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{self.idomain: sync_i, self.odomain: sync_o},
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specials={MultiReg(toggle_i, self.idomain, toggle_o, self.odomain)})
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