litex/examples/basic/graycounter.py

from random import Random

from migen.fhdl.std import *
from migen.genlib.cdc import GrayCounter
from migen.sim.generic import run_simulation

class TB(Module):
	def __init__(self, width=3):
		self.width = width
		self.submodules.gc = GrayCounter(self.width)
		self.prng = Random(7345)

	def do_simulation(self, selfp):
		print("{0:0{1}b} CE={2} bin={3}".format(selfp.gc.q,
			self.width, selfp.gc.ce, selfp.gc.q_binary))
		selfp.gc.ce = self.prng.getrandbits(1)

if __name__ == "__main__":
	run_simulation(TB(), ncycles=35)