46 lines
1.3 KiB
Python
46 lines
1.3 KiB
Python
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# SPDX-License-Identifier: AGPL-3.0-Only
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# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
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import random
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import cocotb
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from cocotb.clock import Clock
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from cocotb.regression import TestFactory
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from cocotb.triggers import FallingEdge, RisingEdge, Timer
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from .util import compare_lists, timeout, send_recovered_bits, with_valids
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def nrzi_decode(bits):
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last = 1
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for bit in bits:
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yield bit ^ last
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last = bit
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@timeout(10, 'us')
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async def test_rx(decoder, valids):
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decoder.nrzi_valid.value = 0
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await Timer(1)
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await cocotb.start(Clock(decoder.clk, 8, units='ns').start())
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ins = [random.randrange(2) for _ in range(1000)]
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await cocotb.start(send_recovered_bits(decoder.clk, decoder.nrzi,
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decoder.nrzi_valid, ins, valids))
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outs = []
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await RisingEdge(decoder.clk)
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for _ in ins:
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await RisingEdge(decoder.clk)
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valid = decoder.nrz_valid.value
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if valid == 0:
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pass
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elif valid == 1:
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outs.append(decoder.nrz[1].value)
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else:
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outs.append(decoder.nrz[1].value)
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outs.append(decoder.nrz[0].value)
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# Ignore the first bit, since it is influenced by the initial value
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compare_lists(list(nrzi_decode(ins))[1:], outs[1:])
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with_valids(globals(), test_rx)
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