from misoclib.liteeth.common import * from misoclib.liteeth.generic import * def _decode_header(h_dict, h_signal, obj): r = [] for k, v in sorted(h_dict.items()): start = v.byte*8+v.offset end = start+v.width r.append(getattr(obj, k).eq(reverse_bytes(h_signal[start:end]))) return r class LiteEthDepacketizer(Module): def __init__(self, sink_description, source_description, header_type, header_length): self.sink = sink = Sink(sink_description) self.source = source = Source(source_description) self.header = Signal(header_length*8) ### dw = flen(sink.data) header_words = (header_length*8)//dw shift = Signal() counter = Counter(max=max(header_words, 2)) self.submodules += counter if header_words == 1: self.sync += \ If(shift, self.header.eq(sink.data) ) else: self.sync += \ If(shift, self.header.eq(Cat(self.header[dw:], sink.data)) ) fsm = FSM(reset_state="IDLE") self.submodules += fsm if header_words == 1: idle_next_state = "COPY" else: idle_next_state = "RECEIVE_HEADER" fsm.act("IDLE", sink.ack.eq(1), counter.reset.eq(1), If(sink.stb, shift.eq(1), NextState(idle_next_state) ) ) if header_words != 1: fsm.act("RECEIVE_HEADER", sink.ack.eq(1), If(sink.stb, counter.ce.eq(1), shift.eq(1), If(counter.value == header_words-2, NextState("COPY") ) ) ) no_payload = Signal() self.sync += \ If(fsm.before_entering("COPY"), source.sop.eq(1), no_payload.eq(sink.eop) ).Elif(source.stb & source.ack, source.sop.eq(0) ) self.comb += [ source.eop.eq(sink.eop | no_payload), source.data.eq(sink.data), source.error.eq(sink.error), _decode_header(header_type, self.header, source) ] fsm.act("COPY", sink.ack.eq(source.ack), source.stb.eq(sink.stb | no_payload), If(source.stb & source.ack & source.eop, NextState("IDLE") ) )