2d2ab6e09d
It is not correct to access domain properties from user code, because it will not match the reality if DomainRenamer has been applied to the module.
62 lines
1.9 KiB
Python
62 lines
1.9 KiB
Python
import warnings
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from ...tools import deprecated
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from ...lib.cdc import MultiReg as NativeMultiReg
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from ...hdl.ast import *
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from ..fhdl.module import CompatModule
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from ..fhdl.structure import If
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__all__ = ["MultiReg", "GrayCounter", "GrayDecoder"]
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class MultiReg(NativeMultiReg):
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def __init__(self, i, o, odomain="sync", n=2, reset=0):
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if odomain != "sync":
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warnings.warn("instead of `MultiReg(..., odomain={!r})`, "
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"use `MultiReg(..., o_domain={!r})`"
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.format(odomain, odomain),
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DeprecationWarning, stacklevel=2)
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super().__init__(i, o, o_domain=odomain, n=n, reset=reset)
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self.odomain = odomain
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@deprecated("instead of `migen.genlib.cdc.GrayCounter`, use `nmigen.lib.coding.GrayEncoder`")
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class GrayCounter(CompatModule):
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def __init__(self, width):
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self.ce = Signal()
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self.q = Signal(width)
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self.q_next = Signal(width)
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self.q_binary = Signal(width)
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self.q_next_binary = Signal(width)
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###
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self.comb += [
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If(self.ce,
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self.q_next_binary.eq(self.q_binary + 1)
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).Else(
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self.q_next_binary.eq(self.q_binary)
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),
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self.q_next.eq(self.q_next_binary ^ self.q_next_binary[1:])
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]
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self.sync += [
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self.q_binary.eq(self.q_next_binary),
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self.q.eq(self.q_next)
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]
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@deprecated("instead of `migen.genlib.cdc.GrayDecoder`, use `nmigen.lib.coding.GrayDecoder`")
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class GrayDecoder(CompatModule):
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def __init__(self, width):
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self.i = Signal(width)
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self.o = Signal(width, reset_less=True)
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# # #
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o_comb = Signal(width)
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self.comb += o_comb[-1].eq(self.i[-1])
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for i in reversed(range(width-1)):
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self.comb += o_comb[i].eq(o_comb[i+1] ^ self.i[i])
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self.sync += self.o.eq(o_comb)
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