78 lines
1.8 KiB
Python
78 lines
1.8 KiB
Python
from liteeth.common import *
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def _encode_header(h_dict, h_signal, obj):
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r = []
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for k, v in sorted(h_dict.items()):
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start = v.byte*8+v.offset
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end = start+v.width
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r.append(h_signal[start:end].eq(reverse_bytes(getattr(obj, k))))
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return r
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class LiteEthPacketizer(Module):
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def __init__(self, sink_description, source_description, header_type, header_length):
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self.sink = sink = Sink(sink_description)
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self.source = source = Source(source_description)
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self.header = Signal(header_length*8)
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###
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dw = flen(self.sink.data)
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header_reg = Signal(header_length*8)
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load = Signal()
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shift = Signal()
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counter = Counter(max=header_length//(dw//8))
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self.submodules += counter
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self.comb += _encode_header(header_type, self.header, sink)
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self.sync += [
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If(load,
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header_reg.eq(self.header)
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).Elif(shift,
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header_reg.eq(Cat(header_reg[dw:], Signal(dw)))
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)
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]
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fsm = FSM(reset_state="IDLE")
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self.submodules += fsm
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fsm.act("IDLE",
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sink.ack.eq(1),
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counter.reset.eq(1),
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If(sink.stb & sink.sop,
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sink.ack.eq(0),
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source.stb.eq(1),
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source.sop.eq(1),
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source.eop.eq(0),
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source.data.eq(self.header[:dw]),
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If(source.stb & source.ack,
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load.eq(1),
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NextState("SEND_HEADER"),
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)
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)
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)
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fsm.act("SEND_HEADER",
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source.stb.eq(1),
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source.sop.eq(0),
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source.eop.eq(sink.eop & (counter.value == header_length//(dw//8)-2)),
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source.data.eq(header_reg[dw:2*dw]),
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If(source.stb & source.ack,
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shift.eq(1),
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counter.ce.eq(1),
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If(counter.value == header_length//(dw//8)-2,
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NextState("COPY")
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)
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)
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)
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fsm.act("COPY",
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source.stb.eq(sink.stb),
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source.sop.eq(0),
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source.eop.eq(sink.eop),
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source.data.eq(sink.data),
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source.error.eq(sink.error),
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If(source.stb & source.ack,
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sink.ack.eq(1),
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If(source.eop,
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NextState("IDLE")
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)
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)
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)
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