test/test_gearbox.py

   1 import unittest
   2 import random
   3
   4 from migen import *
   5 from migen.genlib.cdc import Gearbox
   6
   7 # TODO:
   8 # connect two gearbox together:
   9 # first gearbox: iwidth > owidth
  10 # second gearbox: iwidth < owidth
  11 # use 2 clock domains
  12 # compare input data to output data, should be similar
  13 # various datawidth/clock ratios
  14
  15
  16 def data_generator(dut):
  17     for i in range(256):
  18         yield dut.i.eq(i)
  19         yield
  20     yield
  21
  22 @passive
  23 def data_checker(dut):
  24     while True:
  25         #print((yield dut.o))
  26         yield
  27
  28
  29 class GearboxDUT(Module):
  30     def __init__(self):
  31         self.submodules.gearbox_down = Gearbox(10, "user", 8, "gearbox")
  32         self.submodules.gearbox_up = Gearbox(8, "gearbox", 10, "user")
  33         self.comb += self.gearbox_up.i.eq(self.gearbox_down.o)
  34         self.i, self.o = self.gearbox_down.i, self.gearbox_up.o
  35
  36
  37 class TestGearbox(unittest.TestCase):
  38     def test_gearbox(self):
  39         dut = GearboxDUT()
  40         generators = {"user": [data_generator(dut), data_checker(dut)]}
  41         clocks = {"user": 12.5, "gearbox": 10}
  42         run_simulation(dut, generators, clocks, vcd_name="sim.vcd")
  43         self.assertEqual(0, 0)