test: add test_gearbox skeleton

test/test_gearbox.py

@@ -0,0 +1,33 @@
+import unittest
+import random
+
+from litex.gen import *
+from litex.gen.genlib.cdc import Gearbox
+
+# TODO:
+# connect two gearbox together:
+# first gearbox: iwidth > owidth
+# second gearbox: iwidth < owidth
+# use 2 clock domains
+# compare input data to output data, should be similar
+# various datawidth/clock ratios
+
+def source_generator(dut):
+    yield
+
+
+def sink_generator(duc):
+    yield
+
+
+class GearboxDUT(Module):
+    def __init__(self):
+        self.submodules.gearbox_down = Gearbox(10, "slow", 8, "fast")
+        self.submodules.gearbox_up = Gearbox(8, "fast", 10, "slow")
+        self.comb += self.gearbox_up.i.eq(self.gearbox_down.o)
+        self.i, self.o = self.gearbox_down.i, self.gearbox_up.o
+
+
+class TestGearbox(unittest.TestCase):
+    def test_gearbox(self):
+        self.assertEqual(0, 0)