7df70059d1
The redesign introduces no fundamental incompatibilities, but it does
involve minor breaking changes:
* The simulator commands were moved from hdl.ast to back.pysim
(instead of only being reexported from back.pysim).
* back.pysim.DeadlineError was removed.
Summary of changes:
* The new simulator compiles HDL to Python code and is >6x faster.
(The old one compiled HDL to lots of Python lambdas.)
* The new simulator is a straightforward, rigorous implementation
of the Synchronous Reactive Programming paradigm, instead of
a pile of ad-hoc code with no particular design driving it.
* The new simulator never raises DeadlineError, and there is no
limit on the amount of delta cycles.
* The new simulator robustly handles multiclock designs.
* The new simulator can be reset, such that the compiled design
can be reused, which can save significant runtime with large
designs.
* Generators can no longer be added as processes, since that would
break reset(); only generator functions may be. If necessary,
they may be added by wrapping them into a generator function;
a deprecated fallback does just that. This workaround will raise
an exception if the simulator is reset and restarted.
* The new simulator does not depend on Python extensions.
(The old one required bitarray, which did not provide wheels.)
Fixes #28.
Fixes #34.
Fixes #160.
Fixes #161.
Fixes #215.
Fixes #242.
Fixes #262.
127 lines
3.5 KiB
Python
127 lines
3.5 KiB
Python
from .utils import *
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from ..hdl import *
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from ..asserts import *
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from ..back.pysim import *
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from ..lib.coding import *
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class EncoderTestCase(FHDLTestCase):
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def test_basic(self):
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enc = Encoder(4)
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def process():
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0001)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0100)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 2)
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yield enc.i.eq(0b0110)
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yield Settle()
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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sim = Simulator(enc)
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sim.add_process(process)
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sim.run()
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class PriorityEncoderTestCase(FHDLTestCase):
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def test_basic(self):
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enc = PriorityEncoder(4)
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def process():
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self.assertEqual((yield enc.n), 1)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0001)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 0)
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yield enc.i.eq(0b0100)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 2)
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yield enc.i.eq(0b0110)
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yield Settle()
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self.assertEqual((yield enc.n), 0)
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self.assertEqual((yield enc.o), 1)
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sim = Simulator(enc)
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sim.add_process(process)
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sim.run()
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class DecoderTestCase(FHDLTestCase):
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def test_basic(self):
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dec = Decoder(4)
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def process():
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self.assertEqual((yield dec.o), 0b0001)
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yield dec.i.eq(1)
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yield Settle()
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self.assertEqual((yield dec.o), 0b0010)
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yield dec.i.eq(3)
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yield Settle()
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self.assertEqual((yield dec.o), 0b1000)
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yield dec.n.eq(1)
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yield Settle()
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self.assertEqual((yield dec.o), 0b0000)
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sim = Simulator(dec)
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sim.add_process(process)
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sim.run()
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class ReversibleSpec(Elaboratable):
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def __init__(self, encoder_cls, decoder_cls, args):
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self.encoder_cls = encoder_cls
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self.decoder_cls = decoder_cls
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self.coder_args = args
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def elaborate(self, platform):
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m = Module()
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enc, dec = self.encoder_cls(*self.coder_args), self.decoder_cls(*self.coder_args)
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m.submodules += enc, dec
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m.d.comb += [
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dec.i.eq(enc.o),
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Assert(enc.i == dec.o)
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]
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return m
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class HammingDistanceSpec(Elaboratable):
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def __init__(self, distance, encoder_cls, args):
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self.distance = distance
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self.encoder_cls = encoder_cls
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self.coder_args = args
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def elaborate(self, platform):
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m = Module()
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enc1, enc2 = self.encoder_cls(*self.coder_args), self.encoder_cls(*self.coder_args)
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m.submodules += enc1, enc2
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m.d.comb += [
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Assume(enc1.i + 1 == enc2.i),
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Assert(sum(enc1.o ^ enc2.o) == self.distance)
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]
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return m
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class GrayCoderTestCase(FHDLTestCase):
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def test_reversible(self):
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spec = ReversibleSpec(encoder_cls=GrayEncoder, decoder_cls=GrayDecoder, args=(16,))
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self.assertFormal(spec, mode="prove")
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def test_distance(self):
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spec = HammingDistanceSpec(distance=1, encoder_cls=GrayEncoder, args=(16,))
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self.assertFormal(spec, mode="prove")
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