230 lines
7.7 KiB
Python
230 lines
7.7 KiB
Python
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# nmigen: UnusedElaboratable=no
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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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sim = Simulator(frag)
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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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sim = Simulator(frag)
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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 AsyncFFSynchronizerTestCase(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_edge_wrong(self):
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with self.assertRaises(ValueError,
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msg="AsyncFFSynchronizer async edge must be one of 'pos' or 'neg', not 'xxx'"):
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AsyncFFSynchronizer(Signal(), Signal(), domain="sync", async_edge="xxx")
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def test_pos_edge(self):
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i = Signal()
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o = Signal()
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m = Module()
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m.domains += ClockDomain("sync")
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m.submodules += AsyncFFSynchronizer(i, o)
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sim = Simulator(m)
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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 i), 0)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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yield i.eq(1)
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yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield i.eq(0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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sim.add_process(process)
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with sim.write_vcd("test.vcd"):
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sim.run()
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def test_neg_edge(self):
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i = Signal(reset=1)
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o = Signal()
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m = Module()
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m.domains += ClockDomain("sync")
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m.submodules += AsyncFFSynchronizer(i, o, async_edge="neg")
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sim = Simulator(m)
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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 i), 1)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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yield i.eq(0)
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yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield i.eq(1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 1)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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self.assertEqual((yield o), 0)
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yield Tick(); yield Delay(1e-8)
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sim.add_process(process)
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with sim.write_vcd("test.vcd"):
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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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sim = Simulator(m)
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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), 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 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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with sim.write_vcd("test.vcd"):
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sim.run()
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# TODO: test with distinct clocks
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class PulseSynchronizerTestCase(FHDLTestCase):
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def test_paramcheck(self):
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with self.assertRaises(TypeError):
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ps = PulseSynchronizer("w", "r", sync_stages=0)
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with self.assertRaises(TypeError):
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ps = PulseSynchronizer("w", "r", sync_stages="abc")
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ps = PulseSynchronizer("w", "r", sync_stages = 1)
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def test_smoke(self):
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m = Module()
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m.domains += ClockDomain("sync")
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ps = m.submodules.dut = PulseSynchronizer("sync", "sync")
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sim = Simulator(m)
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sim.add_clock(1e-6)
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def process():
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yield ps.i.eq(0)
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# TODO: think about reset
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for n in range(5):
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yield Tick()
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# Make sure no pulses are generated in quiescent state
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for n in range(3):
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yield Tick()
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self.assertEqual((yield ps.o), 0)
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# Check conservation of pulses
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accum = 0
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for n in range(10):
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yield ps.i.eq(1 if n < 4 else 0)
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yield Tick()
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accum += yield ps.o
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self.assertEqual(accum, 4)
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sim.add_process(process)
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sim.run()
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