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 *
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from migen.corelogic import timeline
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class WB2CSR():
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def __init__(self):
self.wishbone = wishbone.Slave()
self.csr = csr.Master()
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self.timeline = timeline.Timeline(self.wishbone.cyc_i & self.wishbone.stb_i,
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[(1, [self.csr.we_o.eq(self.wishbone.we_i)]),
(2, [self.wishbone.ack_o.eq(1)]),
(3, [self.wishbone.ack_o.eq(0)])])
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def get_fragment(self):
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sync = [
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self.csr.we_o.eq(0),
self.csr.d_o.eq(self.wishbone.dat_i),
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self.csr.a_o.eq(self.wishbone.adr_i[:14]),
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self.wishbone.dat_o.eq(self.csr.d_i)
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]
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return Fragment(sync=sync) + self.timeline.get_fragment()