ethernet/tb/axis_replay_buffer.py

105 lines
3.4 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-Only
# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
import cocotb
from cocotb.clock import Clock
from cocotb.regression import TestFactory
from cocotb.triggers import ClockCycles, FallingEdge, RisingEdge, Timer
from .util import ClockEnable, lookahead, timeout
BUF_SIZE = 54
async def send_packet(signals, packet, ratio=1):
for val, last in lookahead(packet):
if 'err' in signals:
if val is None:
signals['data'].value = 0
signals['err'].value = 1
else:
signals['data'].value = val
signals['err'].value = 0
else:
signals['data'].value = val
signals['valid'].value = 1
signals['last'].value = last
await RisingEdge(signals['clk'])
while True:
await FallingEdge(signals['clk'])
if signals['ready'].value:
break
signals['valid'].value = 0
if ratio != 1:
await ClockCycles(signals['clk'], ratio - 1, rising=False)
@timeout(30, 'us')
async def test_replay(buf, in_ratio, out_ratio):
buf.s_axis_valid.value = 0
buf.s_axis_last.value = 0
buf.m_axis_ready.value = 1
buf.replay.value = 0
buf.done.value = 0
await Timer(1)
await cocotb.start(Clock(buf.clk, 8, units='ns').start())
await FallingEdge(buf.clk)
await cocotb.start(ClockEnable(buf.clk, buf.m_axis_ready, out_ratio))
# A packet equal to BUF_SIZE, one around 2**BUF_WIDTH, and one around
# 2**(BUF_WIDTH + 1) (plus some extra). This should capture most of the fun
# conditions. We start at different data values to make sure we aren't
# reusing anything from the last test.
packets = [list(range(54)), list(range(64, 128)), list(range(128, 512))]
async def send():
for packet in packets:
await send_packet({
'clk': buf.clk,
'data': buf.s_axis_data,
'valid': buf.s_axis_valid,
'last': buf.s_axis_last,
'ready': buf.s_axis_ready,
}, packet, in_ratio)
async def recv(packet):
async def handshake():
while not buf.m_axis_valid.value or not buf.m_axis_ready.value:
await RisingEdge(buf.clk)
async def recv_len(length):
for i, val in enumerate(packet[:length]):
await handshake()
assert buf.m_axis_data.value == val
assert buf.m_axis_last == (i == len(packet) - 1)
await RisingEdge(buf.clk)
async def restart():
await FallingEdge(buf.clk)
assert buf.replayable.value
buf.replay.value = 1
await FallingEdge(buf.clk)
buf.replay.value = 0
buf.done.value = 0
replayable = min(len(packet), BUF_SIZE)
await recv_len(replayable - 3)
await restart()
await recv_len(replayable - 2)
# As long as the packet is <= BUF_SIZE we should be able to wait
# Try it out
if len(packet) <= BUF_SIZE:
await ClockCycles(buf.clk, 3)
await restart()
buf.done.value = 1
await recv_len(len(packet))
await cocotb.start(send())
for packet in packets:
await recv(packet)
replay_tests = TestFactory(test_replay)
replay_tests.add_option('in_ratio', (1, 4))
replay_tests.add_option('out_ratio', (1, 4))
replay_tests.generate_tests()