89 lines
2.1 KiB
Python
89 lines
2.1 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-Only
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# Copyright (C) 2023 Sean Anderson <seanga2@gmail.com>
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import cocotb
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from cocotb.binary import BinaryValue
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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, Timer
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from cocotb.utils import get_sim_time, get_sim_steps
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from .axis_replay_buffer import recv_packet
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from .util import ClockEnable, timeout
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BAUD = 4e6
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BIT_STEPS = get_sim_steps(1 / BAUD, 'sec', round_mode='round')
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def as_bits(c):
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for _ in range(8):
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yield c & 1
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c >>= 1
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async def putchar(rx, c):
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for bit in (0, *as_bits(c), 1):
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rx.value = bit
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await Timer(BIT_STEPS)
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@timeout(1, 'ms')
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async def test_rx(uart, ratio):
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uart.clk.value = BinaryValue('Z')
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uart.rst.value = 1
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uart.ready.value = 0
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uart.rx.value = 1
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uart.high_speed.value = 1
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await Timer(1)
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uart.rst.value = 0
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await cocotb.start(Clock(uart.clk, 8, units='ns').start())
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await FallingEdge(uart.clk)
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ce = await cocotb.start(ClockEnable(uart.clk, uart.ready, ratio))
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msg = b"Hell\0"
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signals = {
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'clk': uart.clk,
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'data': uart.data,
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'valid': uart.valid,
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'ready': uart.ready,
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}
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await cocotb.start(recv_packet(signals, msg))
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for c in msg:
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await putchar(uart.rx, c)
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overflows = 0
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frame_errors = 0
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async def count_errors():
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nonlocal overflows
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nonlocal frame_errors
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while True:
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await FallingEdge(uart.clk)
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overflows += uart.overflow.value
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frame_errors += uart.frame_error.value
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monitor = await cocotb.start(count_errors())
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uart.rx.value = 0
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await Timer(BIT_STEPS * 20)
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uart.rx.value = 1
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await Timer(BIT_STEPS)
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assert frame_errors == 1
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ce.kill()
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uart.ready.value = 0
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await putchar(uart.rx, 0xFF)
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await putchar(uart.rx, 0)
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assert overflows == 1
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uart.ready.value = 1
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await recv_packet(signals, (0xFF,))
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monitor.kill()
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uart_tests = TestFactory(test_rx)
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uart_tests.add_option('ratio', (1, 4))
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uart_tests.generate_tests()
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