39 lines
1.0 KiB
Python
39 lines
1.0 KiB
Python
# 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.triggers import FallingEdge, RisingEdge, Timer
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from .util import compare_lists
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def nrzi_encode(bits):
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last = 1
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for bit in bits:
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yield (last := last ^ bit)
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@cocotb.test(timeout_time=100, timeout_unit='us')
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async def test_encode(encoder):
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ins = [random.randrange(2) for _ in range(1000)]
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encoder.nrz.value = ins[0]
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await Timer(1)
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await cocotb.start(Clock(encoder.clk, 8, units='ns').start())
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async def send_nrz():
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for bit in ins:
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await FallingEdge(encoder.clk)
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encoder.nrz.value = bit
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await cocotb.start(send_nrz())
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outs = []
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await RisingEdge(encoder.clk)
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await RisingEdge(encoder.clk)
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for _ in ins:
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await RisingEdge(encoder.clk)
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outs.append(encoder.nrzi.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_encode(ins[1:])), outs[1:])
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