amaranth/nmigen/genlib/cdc.py
2018-12-13 02:06:58 +00:00

26 lines
727 B
Python

from ..fhdl import *
__all__ = ["MultiReg"]
class MultiReg:
def __init__(self, i, o, odomain="sys", n=2, reset=0):
self.i = i
self.o = o
self.odomain = odomain
self._regs = [Signal(self.i.shape(), name="cdc{}".format(i), reset=reset, reset_less=True,
attrs={"no_retiming": True})
for i in range(n)]
def get_fragment(self, platform):
if hasattr(platform, "get_multi_reg"):
return platform.get_multi_reg(self)
m = Module()
for i, o in zip((self.i, *self._regs), self._regs):
m.d[self.odomain] += o.eq(i)
m.d.comb += self.o.eq(self._regs[-1])
return m.lower(platform)