59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
from migen.fhdl.structure import *
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from migen.bus import wishbone
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from migen.flow.actor import *
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class Reader(Actor):
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def __init__(self):
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self.bus = wishbone.Interface()
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Actor.__init__(self,
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("address", Sink, [("a", 30)]),
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("data", Source, [("d", 32)]))
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def get_fragment(self):
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bus_stb = Signal()
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data_reg_loaded = Signal()
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data_reg = Signal(32)
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comb = [
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self.busy.eq(data_reg_loaded),
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self.bus.we.eq(0),
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bus_stb.eq(self.endpoints["address"].stb & (~data_reg_loaded | self.endpoints["data"].ack)),
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self.bus.cyc.eq(bus_stb),
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self.bus.stb.eq(bus_stb),
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self.bus.adr.eq(self.token("address").a),
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self.endpoints["address"].ack.eq(self.bus.ack),
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self.endpoints["data"].stb.eq(data_reg_loaded),
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self.token("data").d.eq(data_reg)
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]
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sync = [
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If(self.endpoints["data"].ack,
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data_reg_loaded.eq(0)
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),
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If(self.bus.ack,
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data_reg_loaded.eq(1),
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data_reg.eq(self.bus.dat_r)
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)
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]
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return Fragment(comb, sync)
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class Writer(Actor):
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def __init__(self):
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self.bus = wishbone.Interface()
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Actor.__init__(self,
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("address_data", Sink, [("a", 30), ("d", 32)]))
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def get_fragment(self):
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comb = [
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self.busy.eq(0),
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self.bus.we.eq(1),
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self.bus.cyc.eq(self.endpoints["address_data"].stb),
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self.bus.stb.eq(self.endpoints["address_data"].stb),
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self.bus.adr.eq(self.token("address_data").a),
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self.bus.sel.eq(0xf),
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self.bus.dat_w.eq(self.token("address_data").d),
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self.endpoints["address_data"].ack.eq(self.bus.ack)
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]
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return Fragment(comb)
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