litex/examples/basic/graycounter.py

from random import Random

from migen.fhdl.std import *
from migen.genlib.cdc import GrayCounter
from migen.sim import Simulator


def tb(dut):
    prng = Random(7345)
    for i in range(35):
        print("{0:0{1}b} CE={2} bin={3}".format((yield dut.q),
            flen(dut.q), (yield dut.ce), (yield dut.q_binary)))
        yield dut.ce, prng.getrandbits(1)
        yield


if __name__ == "__main__":
    dut = GrayCounter(3)
    Simulator(dut, tb(dut)).run()