ethernet/tb/pcs.py

274 lines
7.3 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-Only
# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
import enum
import itertools
import cocotb
from cocotb.clock import Clock
from cocotb.regression import TestFactory
from cocotb.triggers import ClockCycles, Edge, RisingEdge, FallingEdge, Timer
from cocotb.types import LogicArray
from .util import *
class Code(enum.Enum):
_0 = (0b11110, '0')
_1 = (0b01001, '1')
_2 = (0b10100, '2')
_3 = (0b10101, '3')
_4 = (0b01010, '4')
_5 = (0b01011, '5')
_6 = (0b01110, '6')
_7 = (0b01111, '7')
_8 = (0b10010, '8')
_9 = (0b10011, '9')
_A = (0b10110, 'A')
_B = (0b10111, 'B')
_C = (0b11010, 'C')
_D = (0b11011, 'D')
_E = (0b11100, 'E')
_F = (0b11101, 'F')
_I = (0b11111, 'I')
_J = (0b11000, 'J')
_K = (0b10001, 'K')
_T = (0b01101, 'T')
_R = (0b00111, 'R')
_H = (0b00100, 'H')
_V0 = (0b00000, 'V')
_V1 = (0b00001, 'V')
_V2 = (0b00010, 'V')
_V3 = (0b00011, 'V')
_V4 = (0b00101, 'V')
_V5 = (0b00110, 'V')
_V6 = (0b01000, 'V')
_V7 = (0b01100, 'V')
_V8 = (0b10000, 'V')
_V9 = (0b11001, 'V')
@classmethod
def _missing_(cls, value):
return cls.__members__['_' + value]
@classmethod
def decode(cls, bits):
value = 0
for bit in bits:
value = (value << 1) | bit
return cls(value)
@classproperty
def encode(cls):
if not hasattr(cls, '_encode'):
cls._encode = { data: cls(f"{data:X}") for data in range(16) }
return cls._encode
def __new__(cls, code, name):
self = object.__new__(cls)
self._value_ = code
return self
def __init__(self, code, name):
self._name_ = name
try:
self.data = int(name, 16)
except ValueError:
self.data = None
def __hash__(self):
return hash(self.value)
def __int__(self):
if self.data is None:
raise ValueError
return self.data
def __index__(self):
return self._value_
def __repr__(self):
return f"{self.__class__.__name__}({self._value_:#07b}, '{self.name}')"
def __str__(self):
return f"/{self._name_}/"
def __iter__(self):
code = self.value
for _ in range(5):
yield (code & 0x10) >> 4
code <<= 1
def as_nibbles(data):
for byte in data:
yield byte >> 4
yield byte & 0xf
def as_codes(nibbles):
for nibble in nibbles:
if nibble is None:
yield Code('H')
else:
yield Code.encode[nibble]
def frame(data):
return itertools.chain(
(Code('J'), Code('K')),
# Chop off the SSD
as_codes(data[2:]),
(Code('T'), Code('R')),
)
async def mii_send_packet(pcs, nibbles):
await FallingEdge(pcs.tx_ce)
for nibble in nibbles:
pcs.tx_en.value = 1
pcs.tx_er.value = 0
if nibble is None:
pcs.tx_er.value = 1
else:
pcs.txd.value = nibble
await FallingEdge(pcs.tx_ce)
pcs.tx_en.value = 0
pcs.tx_er.value = 0
pcs.txd.value = LogicArray("XXXX")
await FallingEdge(pcs.tx_ce)
async def mii_recv_packet(pcs):
while not (pcs.rx_ce.value and pcs.rx_dv.value):
await RisingEdge(pcs.rx_clk)
while pcs.rx_dv.value:
if pcs.rx_ce.value:
if pcs.rx_er.value:
yield None
else:
yield pcs.rxd.value
await RisingEdge(pcs.rx_clk)
class PCSError(Exception):
pass
class BadSSD(PCSError):
pass
class PrematureEnd(PCSError):
pass
async def pcs_recv_packet(pcs):
rx_bits = ReverseList([1] * 10)
async def read_bit():
await RisingEdge(pcs.tx_clk)
rx_bits.append(pcs.pma_data_tx.value)
async def read_code():
for _ in range(5):
await read_bit()
async def bad_ssd():
while not all(rx_bits[9:0]):
await read_bit()
raise BadSSDError()
while all(rx_bits[9:2]) or rx_bits[0]:
await read_bit()
if Code.decode(rx_bits[9:5]) != Code('I') or \
Code.decode(rx_bits[4:0]) != Code('J'):
await bad_ssd()
await read_code()
if Code.decode(rx_bits[4:0]) != Code('K'):
await bad_ssd()
yield 0x5
await read_code()
yield 0x5
while any(rx_bits[9:0]):
await read_code()
code = Code.decode(rx_bits[9:5])
if code == Code('T') and Code.decode(rx_bits[4:0]) == Code('R'):
return
yield code.data
raise PrematureEndError()
async def pcs_send_codes(pcs, codes, valids):
await send_recovered_bits(pcs.rx_clk, pcs.pma_data_rx, pcs.pma_data_rx_valid,
itertools.chain(*codes), valids)
@cocotb.test(timeout_time=10, timeout_unit='us')
async def test_tx(pcs):
async def tx_ce():
pcs.tx_ce.value = 1
while True:
await ClockCycles(pcs.tx_clk, 1, False)
pcs.tx_ce.value = 0
await ClockCycles(pcs.tx_clk, 4, False)
pcs.tx_ce.value = 1
pcs.tx_en.value = 0
pcs.tx_er.value = 0
pcs.txd.value = LogicArray("XXXX")
pcs.link_status.value = 1
await cocotb.start(tx_ce())
await Timer(1)
await cocotb.start(Clock(pcs.tx_clk, 8, units='ns').start())
await FallingEdge(pcs.tx_ce)
# Test that all bytes can be transmitted
packet = list(as_nibbles((0x55, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF)))
# And ensure errors are propagated
packet.insert(10, None)
await cocotb.start(mii_send_packet(pcs, packet))
assert packet == await alist(pcs_recv_packet(pcs))
# Test start errors
await cocotb.start(mii_send_packet(pcs, [None]))
assert [0x5, 0x5, None] == await alist(pcs_recv_packet(pcs))
await cocotb.start(mii_send_packet(pcs, [0x5, None]))
assert [0x5, 0x5, None] == await alist(pcs_recv_packet(pcs))
@timeout(10, 'us')
async def test_rx(pcs, valids):
pcs.pma_data_rx.value = LogicArray('11')
pcs.pma_data_rx_valid.value = 2
pcs.link_status.value = 1
await Timer(1)
await cocotb.start(Clock(pcs.rx_clk, 8, units='ns').start())
packet = list(as_nibbles((0x55, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF)))
# And test errors too
packet.insert(10, None)
await cocotb.start(pcs_send_codes(pcs, itertools.chain(
frame(packet),
# Bad SSDs
(Code('C'), Code('I'), Code('I')),
(Code('J'), Code('I'), Code('I')),
(Code('J'), Code('H'), Code('I'), Code('I')),
# Premature end, plus two clocks since we don't have instant turnaround
(Code('J'), Code('K'), Code('I'), Code('I'), (1,1)),
# Packet spacing
*((*frame([0x55, 0x55]), (1,) * i) for i in range(10))
), valids))
assert packet == await alist(mii_recv_packet(pcs))
for _ in range(3):
while not (pcs.receiving.value and pcs.rx_er.value and pcs.rx_ce.value):
await RisingEdge(pcs.rx_clk)
assert pcs.rxd.value == 0xE
await FallingEdge(pcs.receiving)
assert [0x5, 0x5, None] == await alist(mii_recv_packet(pcs))
# Test packet spacing
for _ in range(10):
assert [0x5, 0x5] == await alist(mii_recv_packet(pcs))
rx_tests = TestFactory(test_rx)
rx_tests.add_option('valids', (one_valid, two_valid, rand_valid, saw_valid()))
rx_tests.generate_tests()