Files
taxi/tb/prim/taxi_arbiter/test_taxi_arbiter.py
Alex Forencich 46e60d32f2 prim: Add arbiter module and testbench
Signed-off-by: Alex Forencich <alex@alexforencich.com>
2025-02-28 21:04:49 -08:00

336 lines
8.4 KiB
Python

#!/usr/bin/env python
# SPDX-License-Identifier: CERN-OHL-S-2.0
"""
Copyright (c) 2020-2025 FPGA Ninja, LLC
Authors:
- Alex Forencich
"""
import logging
import os
import cocotb_test.simulator
import pytest
import cocotb
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge
class TB(object):
def __init__(self, dut):
self.dut = dut
self.log = logging.getLogger("cocotb.tb")
self.log.setLevel(logging.DEBUG)
cocotb.start_soon(Clock(dut.clk, 10, units="ns").start())
dut.req.setimmediatevalue(0)
dut.ack.setimmediatevalue(0)
async def reset(self):
self.dut.rst.setimmediatevalue(0)
await RisingEdge(self.dut.clk)
await RisingEdge(self.dut.clk)
self.dut.rst.value = 1
await RisingEdge(self.dut.clk)
await RisingEdge(self.dut.clk)
self.dut.rst.value = 0
await RisingEdge(self.dut.clk)
await RisingEdge(self.dut.clk)
@cocotb.test()
async def run_single_bit(dut):
tb = TB(dut)
round_robin = bool(int(dut.ARB_ROUND_ROBIN.value))
lsb_high_prio = bool(int(dut.LSB_HIGH_PRIO.value))
await tb.reset()
if lsb_high_prio:
prev_index = 31
else:
prev_index = 0
for i in range(32):
lst = [i]
k = 0
for y in lst:
k = k | 1 << y
tb.log.info("Request: 0x%08x", k)
dut.req.value = k
await RisingEdge(dut.clk)
dut.req.value = 0
await RisingEdge(dut.clk)
if round_robin:
if lsb_high_prio:
# emulate round robin
lst2 = [x for x in lst if x > prev_index]
if len(lst2) == 0:
lst2 = lst
g = min(lst2)
else:
# emulate round robin
lst2 = [x for x in lst if x < prev_index]
if len(lst2) == 0:
lst2 = lst
g = max(lst2)
else:
if lsb_high_prio:
g = min(lst)
else:
g = max(lst)
tb.log.info("Grant (mask): 0x%08x", int(dut.grant.value))
tb.log.info("Grant (index): %d", int(dut.grant_index.value))
assert int(dut.grant.value) == 1 << g
assert int(dut.grant_index.value) == g
prev_index = int(g)
await RisingEdge(dut.clk)
@cocotb.test()
async def run_cycle(dut):
tb = TB(dut)
round_robin = bool(int(dut.ARB_ROUND_ROBIN.value))
lsb_high_prio = bool(int(dut.LSB_HIGH_PRIO.value))
await tb.reset()
if lsb_high_prio:
prev_index = 31
else:
prev_index = 0
for i in range(32):
lst = [0, 5, 10, 15, 20, 25, 30]
k = 0
for y in lst:
k = k | 1 << y
tb.log.info("Request: 0x%08x", k)
dut.req.value = k
await RisingEdge(dut.clk)
dut.req.value = 0
await RisingEdge(dut.clk)
if round_robin:
if lsb_high_prio:
# emulate round robin
lst2 = [x for x in lst if x > prev_index]
if len(lst2) == 0:
lst2 = lst
g = min(lst2)
else:
# emulate round robin
lst2 = [x for x in lst if x < prev_index]
if len(lst2) == 0:
lst2 = lst
g = max(lst2)
else:
if lsb_high_prio:
g = min(lst)
else:
g = max(lst)
tb.log.info("Grant (mask): 0x%08x", int(dut.grant.value))
tb.log.info("Grant (index): %d", int(dut.grant_index.value))
assert int(dut.grant.value) == 1 << g
assert int(dut.grant_index.value) == g
prev_index = int(g)
await RisingEdge(dut.clk)
@cocotb.test()
async def run_two_bits(dut):
tb = TB(dut)
round_robin = bool(int(dut.ARB_ROUND_ROBIN.value))
lsb_high_prio = bool(int(dut.LSB_HIGH_PRIO.value))
await tb.reset()
if lsb_high_prio:
prev_index = 31
else:
prev_index = 0
for i in range(32):
for j in range(32):
lst = [i, j]
k = 0
for y in lst:
k = k | 1 << y
tb.log.info("Request: 0x%08x", k)
dut.req.value = k
await RisingEdge(dut.clk)
dut.req.value = 0
await RisingEdge(dut.clk)
if round_robin:
if lsb_high_prio:
# emulate round robin
lst2 = [x for x in lst if x > prev_index]
if len(lst2) == 0:
lst2 = lst
g = min(lst2)
else:
# emulate round robin
lst2 = [x for x in lst if x < prev_index]
if len(lst2) == 0:
lst2 = lst
g = max(lst2)
else:
if lsb_high_prio:
g = min(lst)
else:
g = max(lst)
tb.log.info("Grant (mask): 0x%08x", int(dut.grant.value))
tb.log.info("Grant (index): %d", int(dut.grant_index.value))
assert int(dut.grant.value) == 1 << g
assert int(dut.grant_index.value) == g
prev_index = int(g)
await RisingEdge(dut.clk)
@cocotb.test()
async def run_five_bits(dut):
tb = TB(dut)
round_robin = bool(int(dut.ARB_ROUND_ROBIN.value))
lsb_high_prio = bool(int(dut.LSB_HIGH_PRIO.value))
await tb.reset()
if lsb_high_prio:
prev_index = 31
else:
prev_index = 0
for i in range(32):
lst = [(i*x) % 32 for x in [1, 3, 5, 7, 11]]
k = 0
for y in lst:
k = k | 1 << y
tb.log.info("Request: 0x%08x", k)
dut.req.value = k
await RisingEdge(dut.clk)
dut.req.value = 0
await RisingEdge(dut.clk)
if round_robin:
if lsb_high_prio:
# emulate round robin
lst2 = [x for x in lst if x > prev_index]
if len(lst2) == 0:
lst2 = lst
g = min(lst2)
else:
# emulate round robin
lst2 = [x for x in lst if x < prev_index]
if len(lst2) == 0:
lst2 = lst
g = max(lst2)
else:
if lsb_high_prio:
g = min(lst)
else:
g = max(lst)
tb.log.info("Grant (mask): 0x%08x", int(dut.grant.value))
tb.log.info("Grant (index): %d", int(dut.grant_index.value))
assert int(dut.grant.value) == 1 << g
assert int(dut.grant_index.value) == g
prev_index = int(g)
await RisingEdge(dut.clk)
# cocotb-test
tests_dir = os.path.abspath(os.path.dirname(__file__))
rtl_dir = os.path.abspath(os.path.join(tests_dir, '..', '..', '..', 'rtl'))
def process_f_files(files):
lst = {}
for f in files:
if f[-2:].lower() == '.f':
with open(f, 'r') as fp:
l = fp.read().split()
for f in process_f_files([os.path.join(os.path.dirname(f), x) for x in l]):
lst[os.path.basename(f)] = f
else:
lst[os.path.basename(f)] = f
return list(lst.values())
@pytest.mark.parametrize("lsb_high_prio", [0, 1])
@pytest.mark.parametrize("round_robin", [0, 1])
def test_taxi_arbiter(request, round_robin, lsb_high_prio):
dut = "taxi_arbiter"
module = os.path.splitext(os.path.basename(__file__))[0]
toplevel = dut
verilog_sources = [
os.path.join(rtl_dir, "prim", f"{dut}.sv"),
os.path.join(rtl_dir, "prim", "taxi_penc.sv"),
]
verilog_sources = process_f_files(verilog_sources)
parameters = {}
parameters['PORTS'] = 32
parameters['ARB_ROUND_ROBIN'] = f"1'b{round_robin}"
parameters['ARB_BLOCK'] = "1'b1"
parameters['ARB_BLOCK_ACK'] = "1'b0"
parameters['LSB_HIGH_PRIO'] = f"1'b{lsb_high_prio}"
extra_env = {f'PARAM_{k}': str(v) for k, v in parameters.items()}
sim_build = os.path.join(tests_dir, "sim_build",
request.node.name.replace('[', '-').replace(']', ''))
cocotb_test.simulator.run(
simulator="verilator",
python_search=[tests_dir],
verilog_sources=verilog_sources,
toplevel=toplevel,
module=module,
parameters=parameters,
sim_build=sim_build,
extra_env=extra_env,
)