2f9dab361f
In context of nMigen, "tools" means "parts of toolchain", so it is confusing to have a completely unrelated module also called "tools".
98 lines
3.4 KiB
Python
98 lines
3.4 KiB
Python
from .utils import *
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from ..hdl import *
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from ..back.pysim import *
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from ..lib.cdc import *
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class FFSynchronizerTestCase(FHDLTestCase):
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def test_stages_wrong(self):
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with self.assertRaises(TypeError,
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msg="Synchronization stage count must be a positive integer, not 0"):
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FFSynchronizer(Signal(), Signal(), stages=0)
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with self.assertRaises(ValueError,
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msg="Synchronization stage count may not safely be less than 2"):
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FFSynchronizer(Signal(), Signal(), stages=1)
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def test_basic(self):
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i = Signal()
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o = Signal()
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frag = FFSynchronizer(i, o)
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with Simulator(frag) as sim:
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sim.add_clock(1e-6)
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def process():
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self.assertEqual((yield o), 0)
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yield i.eq(1)
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yield Tick()
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self.assertEqual((yield o), 0)
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yield Tick()
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self.assertEqual((yield o), 0)
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yield Tick()
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self.assertEqual((yield o), 1)
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sim.add_process(process)
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sim.run()
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def test_reset_value(self):
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i = Signal(reset=1)
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o = Signal()
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frag = FFSynchronizer(i, o, reset=1)
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with Simulator(frag) as sim:
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sim.add_clock(1e-6)
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def process():
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self.assertEqual((yield o), 1)
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yield i.eq(0)
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yield Tick()
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self.assertEqual((yield o), 1)
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yield Tick()
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self.assertEqual((yield o), 1)
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yield Tick()
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self.assertEqual((yield o), 0)
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sim.add_process(process)
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sim.run()
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class ResetSynchronizerTestCase(FHDLTestCase):
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def test_stages_wrong(self):
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with self.assertRaises(TypeError,
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msg="Synchronization stage count must be a positive integer, not 0"):
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ResetSynchronizer(Signal(), stages=0)
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with self.assertRaises(ValueError,
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msg="Synchronization stage count may not safely be less than 2"):
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ResetSynchronizer(Signal(), stages=1)
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def test_basic(self):
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arst = Signal()
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m = Module()
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m.domains += ClockDomain("sync")
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m.submodules += ResetSynchronizer(arst)
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s = Signal(reset=1)
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m.d.sync += s.eq(0)
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with Simulator(m, vcd_file=open("test.vcd", "w")) as sim:
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sim.add_clock(1e-6)
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def process():
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# initial reset
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 0)
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yield Tick(); yield Delay(1e-8)
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yield arst.eq(1)
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yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield arst.eq(0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield s), 0)
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yield Tick(); yield Delay(1e-8)
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sim.add_process(process)
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sim.run()
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