51 lines
1.5 KiB
Python
51 lines
1.5 KiB
Python
from .. import *
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__all__ = ["MultiReg", "ResetSynchronizer"]
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class MultiReg:
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def __init__(self, i, o, odomain="sync", n=2, reset=0):
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self.i = i
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self.o = o
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self.odomain = odomain
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self._regs = [Signal(self.i.shape(), name="cdc{}".format(i),
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reset=reset, reset_less=True, attrs={"no_retiming": True})
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for i in range(n)]
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def elaborate(self, platform):
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if hasattr(platform, "get_multi_reg"):
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return platform.get_multi_reg(self)
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m = Module()
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for i, o in zip((self.i, *self._regs), self._regs):
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m.d[self.odomain] += o.eq(i)
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m.d.comb += self.o.eq(self._regs[-1])
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return m
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class ResetSynchronizer:
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def __init__(self, arst, domain="sync", n=2):
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self.arst = arst
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self.domain = domain
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self._regs = [Signal(name="arst{}".format(i), reset=1,
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attrs={"no_retiming": True})
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for i in range(n)]
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def elaborate(self, platform):
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if hasattr(platform, "get_reset_sync"):
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return platform.get_reset_sync(self)
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m = Module()
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m.domains += ClockDomain("_reset_sync", async_reset=True)
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for i, o in zip((0, *self._regs), self._regs):
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m.d._reset_sync += o.eq(i)
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m.d.comb += [
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ClockSignal("_reset_sync").eq(ClockSignal(self.domain)),
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ResetSignal("_reset_sync").eq(self.arst),
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ResetSignal(self.domain).eq(self._regs[-1])
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]
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return m
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