usb3_pipe/test/test_scrambling.py

# This file is Copyright (c) 2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD

import unittest

from migen import *

from usb3_pipe.scrambling import Scrambler, Descrambler

scrambler_ref = [
    0x14c017ff, 0x8202e7b2, 0xa6286e72, 0x8dbf6dbe,
    0xe6a740be, 0xb2e2d32c, 0x2a770207, 0xe0be34cd,
    0xb1245da7, 0x22bda19b, 0xd31d45d4, 0xee76ead7,
    0xfa1ada2c, 0x3b362d28, 0x676f0e3a, 0x264c06cf,
    0xcd3ae9d3, 0xfc307627, 0xde038b94, 0xf65206d3,
    0x9580884f, 0xf2666ac4, 0x35a10c9f, 0x27cf41e2,
    0x9e7e4074, 0x84fe58a5, 0xa9086009, 0x626f0bf1,
    0xed5c4317, 0xd43f3948, 0xb30ef55a, 0x9b9d03c7,
    0x5c8e0d8b, 0xae779833, 0x3e0bac2d, 0x7a420bda,
    0xa8cfd17c, 0x41ee121c, 0x7a383fc2, 0x01f4690d,
    0xc57231da, 0x0e93d7a0, 0x55a4afdc, 0x1672f0e7,
    0x8438d568, 0x18cd00dd, 0x5930ca9e, 0x771b754c,
    0xcfedc531, 0x3d6e6491, 0x0429e8fe, 0xc4fc6ccf,
    0x62da5e0b, 0xdfab5bba, 0x377db759, 0xc61ae35e,
    0x4ff51488, 0xcb56c88b, 0x634210d3, 0xf7b48a04,
    0x01a00184, 0xee674983, 0xa48b2a3e, 0xd514af76
]

class TestScrambling(unittest.TestCase):
    def test_scrambler_data(self):
        def generator(dut):
            yield dut.source.ready.eq(1)
            yield
            yield dut.sink.data.eq(0)
            yield dut.sink.valid.eq(1)
            yield
            for i in range(64):
                self.assertEqual((yield dut.source.data), scrambler_ref[i])
                yield

        dut = Scrambler(reset=0xffff)
        run_simulation(dut, generator(dut))

    def test_scrambler_ctrl(self):
        def generator(dut):
            yield dut.source.ready.eq(1)
            yield
            yield dut.sink.data.eq(0)
            yield dut.sink.ctrl.eq(0b1111)
            yield dut.sink.valid.eq(1)
            yield
            for i in range(64):
                self.assertEqual((yield dut.source.data), 0)
                yield

        dut = Scrambler(reset=0xffff)
        run_simulation(dut, generator(dut))

    def test_descrambler_data(self):
        def generator(dut):
            for i in range(16):
                yield dut.sink.valid.eq(1)
                yield dut.sink.ctrl.eq(0b1111)
                yield dut.sink.data.eq(0xbcbcbcbc)
                yield
            for i in range(16):
                yield dut.sink.valid.eq(1)
                yield dut.sink.ctrl.eq(0b0000)
                yield dut.sink.data.eq(scrambler_ref[i])
                yield
            yield dut.sink.valid.eq(0)
            for i in range(64):
                yield

        def checker(dut):
            yield dut.source.ready.eq(1)
            yield
            while (yield dut.source.ctrl == 0b1111):
                yield
            for i in range(16):
                self.assertEqual((yield dut.source.data), 0)
                yield

        dut = Descrambler(reset=0xffff)
        run_simulation(dut, [generator(dut), checker(dut)], vcd_name="descrambler.vcd")