class AxiStream(Record):
    def __init__(self, width, direction=None, name=None, fields=None):
        self.width = width
        if direction == 'sink':
            layout = [('TDATA', width, Direction.FANIN),
                      ('TVALID', 1, Direction.FANIN),
                      ('TREADY', 1, Direction.FANOUT),
                      ('TLAST', 1, Direction.FANIN)]
        elif direction == 'source':
            layout = [('TDATA', width, Direction.FANOUT),
                      ('TVALID', 1, Direction.FANOUT),
                      ('TREADY', 1, Direction.FANIN),
                      ('TLAST', 1, Direction.FANOUT)]
        Record.__init__(self, layout, name=name, fields=fields)

class DummyCore(Elaboratable):
    def __init__(self, width_in, width_out):
        self.input = AxiStream(width_in, 'sink', name='INPUT')
        self.output = AxiStream(width_out, 'source', name='OUTPUT')
    def elaborate(self, platform):
        m = Module()
        comb = m.d.comb
        #comb += self.output.connect(self.input) # does not connect the signals
        comb += self.output.TDATA.eq(self.input.TDATA)
        comb += self.output.TVALID.eq(self.input.TVALID)
        comb += self.output.TLAST.eq(self.input.TLAST)
        comb += self.input.TREADY.eq(self.output.TREADY)
        return m