327 lines
9.0 KiB
Python
327 lines
9.0 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-Only
|
|
# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
|
|
|
|
import enum
|
|
import random
|
|
import zlib
|
|
|
|
import cocotb
|
|
from cocotb.binary import BinaryValue
|
|
from cocotb.clock import Clock
|
|
from cocotb.regression import TestFactory
|
|
from cocotb.triggers import ClockCycles, Edge, FallingEdge, First, RisingEdge, Timer
|
|
from cocotb.utils import get_sim_time
|
|
|
|
from . import axis_replay_buffer
|
|
from .pcs_rx import mii_recv_packet
|
|
from .util import alist, lookahead, timeout
|
|
|
|
import os
|
|
|
|
skip_slow = not os.environ.get('RUN_SLOW', False)
|
|
|
|
async def init(mac):
|
|
mac.clk.value = BinaryValue('Z')
|
|
mac.rst.value = 1
|
|
mac.mii_col.value = 0
|
|
mac.mii_crs.value = 0
|
|
mac.axis_valid.value = 0
|
|
mac.axis_err.value = 0
|
|
mac.short_backoff.value = 1
|
|
await Timer(1)
|
|
mac.rst.value = 0
|
|
await cocotb.start(Clock(mac.clk, 8, units='ns').start())
|
|
await FallingEdge(mac.clk)
|
|
|
|
def send_packet(mac, packet, **kwargs):
|
|
return axis_replay_buffer.send_packet({
|
|
'clk': mac.clk,
|
|
'data': mac.axis_data,
|
|
'err': mac.axis_err,
|
|
'valid': mac.axis_valid,
|
|
'last': mac.axis_last,
|
|
'ready': mac.axis_ready,
|
|
}, packet, **kwargs)
|
|
|
|
class MACError(Exception):
|
|
pass
|
|
|
|
class FrameCheckError(MACError):
|
|
pass
|
|
|
|
class AlignmentError(MACError):
|
|
pass
|
|
|
|
class PaddingError(MACError):
|
|
pass
|
|
|
|
async def nibbles_to_bytes(nibbles):
|
|
while True:
|
|
try:
|
|
lo = await anext(nibbles)
|
|
except StopAsyncIteration:
|
|
return
|
|
|
|
try:
|
|
hi = await anext(nibbles)
|
|
except StopAsyncIteration:
|
|
raise AlignmentError
|
|
|
|
yield hi << 4 | lo
|
|
|
|
SFD = 0xd5
|
|
|
|
async def skip_preamble(packet):
|
|
saw_ssd = False
|
|
async for byte in packet:
|
|
if saw_ssd:
|
|
yield byte
|
|
elif byte == SFD:
|
|
saw_ssd = True
|
|
|
|
FCS_GOOD = zlib.crc32(b'\0\0\0\0')
|
|
|
|
async def check_fcs(packet):
|
|
packet = await alist(packet)
|
|
fcs = zlib.crc32(bytes(packet))
|
|
if fcs != FCS_GOOD:
|
|
raise FrameCheckError
|
|
elif len(packet) < 64:
|
|
raise PaddingError
|
|
return packet[:-4]
|
|
|
|
def recv_packet(mac):
|
|
return check_fcs(skip_preamble(nibbles_to_bytes(mii_recv_packet(mac, {
|
|
'ce': mac.mii_tx_ce,
|
|
'data': mac.mii_txd,
|
|
'valid': mac.mii_tx_en,
|
|
}))))
|
|
|
|
async def expect_bad_fcs(mac):
|
|
try:
|
|
await recv_packet(mac)
|
|
except FrameCheckError:
|
|
pass
|
|
else:
|
|
raise AssertionError
|
|
|
|
class Status(enum.Enum):
|
|
OK = enum.auto()
|
|
GAVE_UP = enum.auto()
|
|
LATE_COLLISION = enum.auto()
|
|
UNDERFLOW = enum.auto()
|
|
|
|
async def get_status(mac):
|
|
ok = 0
|
|
gave_up = 0
|
|
late = 0
|
|
underflow = 0
|
|
|
|
while not (ok or gave_up or late or underflow) or mac.mii_tx_en.value:
|
|
ok += mac.transmit_ok.value
|
|
gave_up += mac.gave_up.value
|
|
late += mac.late_collision.value
|
|
underflow += mac.underflow.value
|
|
await FallingEdge(mac.clk)
|
|
|
|
assert ok + gave_up + late + underflow == 1
|
|
if ok:
|
|
return Status.OK
|
|
elif gave_up:
|
|
return Status.GAVE_UP
|
|
elif late:
|
|
return Status.LATE_COLLISION
|
|
elif underflow:
|
|
return Status.UNDERFLOW
|
|
|
|
async def start(mac, packet, **kwargs):
|
|
send = await cocotb.start(send_packet(mac, packet, **kwargs))
|
|
status = await cocotb.start(get_status(mac))
|
|
return send, status
|
|
|
|
BIT_TIME_NS = 10
|
|
BYTE_TIME_NS = 8 * BIT_TIME_NS
|
|
|
|
async def collide(mac, ns, duration=16):
|
|
while not mac.mii_tx_en.value:
|
|
await FallingEdge(mac.clk)
|
|
|
|
if ns > 4:
|
|
await Timer(ns - 4, 'ns')
|
|
mac.mii_col.value = 1
|
|
await Timer(duration, 'ns')
|
|
mac.mii_col.value = 0
|
|
|
|
def randtime(min_bytes, max_bytes):
|
|
return random.randrange(min_bytes * BYTE_TIME_NS, max_bytes * BYTE_TIME_NS)
|
|
|
|
async def restart(mac, ns):
|
|
await cocotb.start(collide(mac, ns))
|
|
await expect_bad_fcs(mac)
|
|
|
|
def compare(actual, expected):
|
|
if actual[:len(expected)] != expected:
|
|
print(actual)
|
|
print(expected)
|
|
raise AssertionError
|
|
|
|
async def ok(mac, packet, status, ns=None):
|
|
if ns is not None:
|
|
await cocotb.start(collide(mac, ns))
|
|
compare(await recv_packet(mac), packet)
|
|
assert await status.join() == Status.OK
|
|
|
|
@timeout(50, 'us')
|
|
async def test_send(mac, ratio):
|
|
await init(mac)
|
|
|
|
packets = (
|
|
list(range(32)),
|
|
list(range(56)),
|
|
list(range(256)),
|
|
)
|
|
|
|
async def send_packets():
|
|
for packet in packets:
|
|
await send_packet(mac, packet, ratio=ratio)
|
|
|
|
await cocotb.start(send_packets())
|
|
for i, packet in enumerate(packets):
|
|
status = await cocotb.start(get_status(mac))
|
|
recv = await cocotb.start(recv_packet(mac))
|
|
|
|
# Measure the IPG to ensure throughput
|
|
start = get_sim_time('ns')
|
|
while not mac.mii_tx_en.value:
|
|
await RisingEdge(mac.clk)
|
|
# The first IPG may not be exact
|
|
if i:
|
|
assert get_sim_time('ns') - start == 12 * 80 - 4
|
|
|
|
compare(await recv.join(), packet)
|
|
assert await status.join() == Status.OK
|
|
|
|
send_tests = TestFactory(test_send)
|
|
send_tests.add_option('ratio', (1, BIT_TIME_NS))
|
|
send_tests.generate_tests()
|
|
|
|
@cocotb.test(timeout_time=100, timeout_unit='us')
|
|
async def test_underflow(mac):
|
|
await init(mac)
|
|
|
|
async def underflow(mac, send, status):
|
|
await expect_bad_fcs(mac)
|
|
await send.join()
|
|
assert await status.join() == Status.UNDERFLOW
|
|
|
|
send, status = await start(mac, range(32), ratio=30)
|
|
await underflow(mac, send, status)
|
|
|
|
#from math import floor
|
|
# Solution to (IPG + PREAMBLE + x) * BIT_TIME = ratio * x
|
|
# end = floor(200 / (ratio - 10))
|
|
|
|
for x in (56, 58, 60):
|
|
# Error on last byte
|
|
send, status = await start(mac, [*range(x), None])
|
|
await underflow(mac, send, status)
|
|
|
|
# Error on last byte valid for one cycle
|
|
send, status = await start(mac, [*range(x), None],
|
|
last_extra=(12 + 8 + x) * 10 - x + 5)
|
|
await underflow(mac, send, status)
|
|
|
|
# Error with more to come
|
|
send, status = await start(mac, [*range(x), None, 1])
|
|
await underflow(mac, send, status)
|
|
|
|
# Underflow with collision
|
|
send, status = await start(mac, [*range(x), None], last_extra=(12 + 8 + x) * 10)
|
|
await restart(mac, (8 + x) * BYTE_TIME_NS - 1)
|
|
if x <= 56:
|
|
await underflow(mac, send, status)
|
|
else:
|
|
await send.join()
|
|
assert await status.join() == Status.LATE_COLLISION
|
|
|
|
@cocotb.test(timeout_time=1250, timeout_unit='us', skip=skip_slow)
|
|
async def test_backoff(mac):
|
|
await init(mac)
|
|
|
|
packet = list(range(32))
|
|
for collisions in (15, 16):
|
|
send, status = await start(mac, packet)
|
|
then = None
|
|
for n in range(collisions):
|
|
await restart(mac, 0)
|
|
now = get_sim_time('ns')
|
|
if then is not None:
|
|
assert now - then <= (8 + 4 + 12 + 2 ** min(n, 10)) * BYTE_TIME_NS
|
|
then = now
|
|
|
|
if collisions == 16:
|
|
assert await status.join() == Status.GAVE_UP
|
|
else:
|
|
await ok(mac, packet, status)
|
|
|
|
@cocotb.test(timeout_time=10, timeout_unit='us')
|
|
async def test_defer(mac):
|
|
await init(mac)
|
|
|
|
# Skip to the end of IPG_LATE
|
|
mac.mii_crs.value = 1
|
|
await Timer(13 * BYTE_TIME_NS, 'ns')
|
|
packet = list(range(32))
|
|
send, status = await start(mac, packet)
|
|
# Ensure IPG_EARLY works
|
|
await Timer(13 * BYTE_TIME_NS, 'ns')
|
|
assert not mac.mii_tx_en.value
|
|
|
|
# Test the early 2/3s; not exact since the last 1/3 takes the slack
|
|
mac.mii_crs.value = 0
|
|
await Timer(7 * BYTE_TIME_NS, 'ns')
|
|
mac.mii_crs.value = 1
|
|
await Timer(6 * BYTE_TIME_NS, 'ns')
|
|
assert not mac.mii_tx_en.value
|
|
|
|
# And the late
|
|
mac.mii_crs.value = 0
|
|
await Timer(8 * BYTE_TIME_NS, 'ns')
|
|
mac.mii_crs.value = 1
|
|
await Timer(5 * BYTE_TIME_NS, 'ns')
|
|
assert mac.mii_tx_en.value
|
|
assert await status.join() == Status.OK
|
|
|
|
@cocotb.test(timeout_time=150, timeout_unit='us')
|
|
async def test_collision(mac):
|
|
await init(mac)
|
|
|
|
async def late(mac, packet, ns):
|
|
send, status = await start(mac, packet)
|
|
await restart(mac, ns)
|
|
await send.join()
|
|
assert await status.join() == Status.LATE_COLLISION
|
|
|
|
packet = list(range(32))
|
|
send, status = await start(mac, packet)
|
|
await restart(mac, randtime(0, 8))
|
|
await restart(mac, randtime(8, 40))
|
|
await restart(mac, randtime(40, 64))
|
|
await restart(mac, 64 * BYTE_TIME_NS - 1)
|
|
await ok(mac, packet, status, 72 * BYTE_TIME_NS)
|
|
|
|
await late(mac, packet, 64 * BYTE_TIME_NS)
|
|
await late(mac, packet, randtime(64, 72))
|
|
await late(mac, packet, (8 + 64) * BYTE_TIME_NS - 1)
|
|
|
|
packet = list(range(256))
|
|
send, status = await start(mac, packet)
|
|
await restart(mac, randtime(8, 40))
|
|
await restart(mac, randtime(40, 64))
|
|
await restart(mac, 64 * BYTE_TIME_NS - 1)
|
|
await ok(mac, packet, status, (8 + 256 + 4) * BYTE_TIME_NS)
|
|
|
|
await late(mac, packet, 64 * BYTE_TIME_NS)
|
|
await late(mac, packet, randtime(64, 256))
|
|
await late(mac, packet, 72 * BYTE_TIME_NS - 1)
|