ethernet/tb/pcs.py

296 lines
7.8 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-Only
# Copyright (C) 2022 Sean Anderson <seanga2@gmail.com>
import enum
import random
import itertools
import cocotb
from cocotb.clock import Clock
from cocotb.triggers import ClockCycles, Edge, RisingEdge, FallingEdge, Timer
from cocotb.types import LogicArray
from .util import alist, classproperty, ReverseList
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):
await FallingEdge(pcs.rx_clk)
codes = list(codes)
bits = itertools.chain(*codes)
try:
while True:
#valid = 2
valid = random.randrange(3)
pcs.pma_data_rx_valid.value = valid
if valid == 0:
data = 'XX'
elif valid == 1:
data = (next(bits), 'X')
else:
first = next(bits)
try:
second = next(bits)
except StopIteration:
second = 'X'
data = (first, second)
pcs.pma_data_rx.value = LogicArray(data)
await FallingEdge(pcs.rx_clk)
except StopIteration:
pass
pcs.pma_data_rx_valid.value = 1
pcs.pma_data_rx.value = LogicArray('1X')
@cocotb.test(timeout_time=10, timeout_unit='us')
async def test_tx(pcs):
await cocotb.start(Clock(pcs.tx_clk, 1/125e6, units='sec').start())
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
await cocotb.start(tx_ce())
pcs.tx_en.value = 0
pcs.tx_er.value = 0
pcs.txd.value = LogicArray("XXXX")
pcs.link_status.value = 1
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))
@cocotb.test(timeout_time=10, timeout_unit='us')
async def test_rx(pcs):
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, 1/125e6, units='sec').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
(Code('J'), Code('K'), Code('I'), Code('I')),
)))
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):
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
packet = [0x5, 0x5]
await cocotb.start(pcs_send_codes(pcs, itertools.chain(
*((*frame(packet), (1,) * i) for i in range(10))
)))
for _ in range(10):
assert [0x5, 0x5] == await alist(mii_recv_packet(pcs))