litex/migen/bus/wishbone2csr.py

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from migen.bus import wishbone
from migen.bus import csr
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from migen.fhdl.structure import *
from migen.corelogic.misc import timeline
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class WB2CSR:
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def __init__(self):
self.wishbone = wishbone.Interface()
self.csr = csr.Interface()
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def get_fragment(self):
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sync = [
self.csr.we.eq(0),
self.csr.dat_w.eq(self.wishbone.dat_w[:8]),
self.csr.adr.eq(self.wishbone.adr[:14]),
self.wishbone.dat_r.eq(self.csr.dat_r)
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]
sync += timeline(self.wishbone.cyc & self.wishbone.stb, [
(1, [self.csr.we.eq(self.wishbone.we)]),
(2, [self.wishbone.ack.eq(1)]),
(3, [self.wishbone.ack.eq(0)])
])
return Fragment(sync=sync)