axis: Add AXI stream FIFO module and testbench

Signed-off-by: Alex Forencich <alex@alexforencich.com>

tb/axis/taxi_axis_fifo/test_taxi_axis_fifo.py

@@ -0,0 +1,512 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: CERN-OHL-S-2.0
+"""
+
+Copyright (c) 2021-2025 FPGA Ninja, LLC
+
+Authors:
+- Alex Forencich
+
+"""
+
+import itertools
+import logging
+import os
+import random
+
+import cocotb_test.simulator
+import pytest
+
+import cocotb
+from cocotb.clock import Clock
+from cocotb.triggers import RisingEdge
+from cocotb.regression import TestFactory
+
+from cocotbext.axi import AxiStreamBus, AxiStreamFrame, AxiStreamSource, AxiStreamSink
+
+
+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())
+
+        self.source = AxiStreamSource(AxiStreamBus.from_entity(dut.s_axis), dut.clk, dut.rst)
+        self.sink = AxiStreamSink(AxiStreamBus.from_entity(dut.m_axis), dut.clk, dut.rst)
+
+        dut.pause_req.setimmediatevalue(0)
+
+    def set_idle_generator(self, generator=None):
+        if generator:
+            self.source.set_pause_generator(generator())
+
+    def set_backpressure_generator(self, generator=None):
+        if generator:
+            self.sink.set_pause_generator(generator())
+
+    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)
+
+
+async def run_test(dut, payload_lengths=None, payload_data=None, idle_inserter=None, backpressure_inserter=None):
+
+    tb = TB(dut)
+
+    id_count = 2**len(tb.source.bus.tid)
+
+    cur_id = 1
+
+    await tb.reset()
+
+    tb.set_idle_generator(idle_inserter)
+    tb.set_backpressure_generator(backpressure_inserter)
+
+    test_frames = []
+
+    for test_data in [payload_data(x) for x in payload_lengths()]:
+        test_frame = AxiStreamFrame(test_data)
+        test_frame.tid = cur_id
+        test_frame.tdest = cur_id
+
+        test_frames.append(test_frame)
+        await tb.source.send(test_frame)
+
+        cur_id = (cur_id + 1) % id_count
+
+    for test_frame in test_frames:
+        rx_frame = await tb.sink.recv()
+
+        assert rx_frame.tdata == test_frame.tdata
+        assert rx_frame.tid == test_frame.tid
+        assert rx_frame.tdest == test_frame.tdest
+        assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_tuser_assert(dut):
+
+    tb = TB(dut)
+
+    await tb.reset()
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
+    test_frame = AxiStreamFrame(test_data, tuser=1)
+    await tb.source.send(test_frame)
+
+    if dut.DROP_BAD_FRAME.value:
+        for k in range(64):
+            await RisingEdge(dut.clk)
+
+    else:
+        rx_frame = await tb.sink.recv()
+
+        assert rx_frame.tdata == test_data
+        assert rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_init_sink_pause(dut):
+
+    tb = TB(dut)
+
+    await tb.reset()
+
+    tb.sink.pause = True
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
+    test_frame = AxiStreamFrame(test_data)
+    await tb.source.send(test_frame)
+
+    for k in range(64):
+        await RisingEdge(dut.clk)
+
+    tb.sink.pause = False
+
+    rx_frame = await tb.sink.recv()
+
+    assert rx_frame.tdata == test_data
+    assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_init_sink_pause_reset(dut):
+
+    tb = TB(dut)
+
+    await tb.reset()
+
+    tb.sink.pause = True
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
+    test_frame = AxiStreamFrame(test_data)
+    await tb.source.send(test_frame)
+
+    for k in range(64):
+        await RisingEdge(dut.clk)
+
+    await tb.reset()
+
+    tb.sink.pause = False
+
+    for k in range(64):
+        await RisingEdge(dut.clk)
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_pause(dut):
+
+    tb = TB(dut)
+
+    byte_lanes = tb.source.byte_lanes
+
+    await tb.reset()
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 16*byte_lanes))
+    test_frame = AxiStreamFrame(test_data)
+
+    for k in range(16):
+        await tb.source.send(test_frame)
+
+    for k in range(60):
+        await RisingEdge(dut.clk)
+
+    dut.pause_req.value = 1
+
+    for k in range(64):
+        await RisingEdge(dut.clk)
+
+    assert tb.sink.idle()
+
+    dut.pause_req.value = 0
+
+    for k in range(16):
+        rx_frame = await tb.sink.recv()
+
+        assert rx_frame.tdata == test_data
+        assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_overflow(dut):
+
+    tb = TB(dut)
+
+    depth = int(dut.DEPTH.value)
+    byte_lanes = tb.source.byte_lanes
+
+    await tb.reset()
+
+    tb.sink.pause = True
+
+    size = (16*byte_lanes)
+    count = depth*2 // size
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), size))
+    test_frame = AxiStreamFrame(test_data)
+    for k in range(count):
+        await tb.source.send(test_frame)
+
+    for k in range((depth//byte_lanes)*3):
+        await RisingEdge(dut.clk)
+
+    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
+        assert tb.source.idle()
+    else:
+        assert not tb.source.idle()
+
+    tb.sink.pause = False
+
+    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
+        for k in range((depth//byte_lanes)*3):
+            await RisingEdge(dut.clk)
+
+        rx_count = 0
+
+        while not tb.sink.empty():
+            rx_frame = await tb.sink.recv()
+
+            if dut.MARK_WHEN_FULL.value and rx_frame.tuser:
+                continue
+
+            assert rx_frame.tdata == test_data
+            assert not rx_frame.tuser
+
+            rx_count += 1
+
+        assert rx_count < count
+
+    else:
+        for k in range(count):
+            rx_frame = await tb.sink.recv()
+
+            assert rx_frame.tdata == test_data
+            assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_test_oversize(dut):
+
+    tb = TB(dut)
+
+    depth = int(dut.DEPTH.value)
+    byte_lanes = tb.source.byte_lanes
+
+    await tb.reset()
+
+    tb.sink.pause = True
+
+    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), depth*2))
+    test_frame = AxiStreamFrame(test_data)
+    await tb.source.send(test_frame)
+
+    for k in range((depth//byte_lanes)*2):
+        await RisingEdge(dut.clk)
+
+    tb.sink.pause = False
+
+    if dut.DROP_OVERSIZE_FRAME.value:
+        for k in range((depth//byte_lanes)*2):
+            await RisingEdge(dut.clk)
+
+    else:
+        rx_frame = await tb.sink.recv()
+
+        if dut.MARK_WHEN_FULL.value:
+            assert rx_frame.tuser
+        else:
+            assert rx_frame.tdata == test_data
+            assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+async def run_stress_test(dut, idle_inserter=None, backpressure_inserter=None):
+
+    tb = TB(dut)
+
+    byte_lanes = tb.source.byte_lanes
+    id_count = 2**len(tb.source.bus.tid)
+
+    cur_id = 1
+
+    await tb.reset()
+
+    tb.set_idle_generator(idle_inserter)
+    tb.set_backpressure_generator(backpressure_inserter)
+
+    test_frames = []
+
+    for k in range(512):
+        length = random.randint(1, byte_lanes*16)
+        test_data = bytearray(itertools.islice(itertools.cycle(range(256)), length))
+        test_frame = AxiStreamFrame(test_data)
+        test_frame.tid = cur_id
+        test_frame.tdest = cur_id
+
+        test_frames.append(test_frame)
+        await tb.source.send(test_frame)
+
+        cur_id = (cur_id + 1) % id_count
+
+    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
+        cycles = 0
+        while cycles < 100:
+            cycles += 1
+            if not tb.source.idle() or dut.s_axis.tvalid.value.integer or dut.m_axis.tvalid.value.integer or dut.status_depth.value.integer:
+                cycles = 0
+            await RisingEdge(dut.clk)
+
+        while not tb.sink.empty():
+            rx_frame = await tb.sink.recv()
+
+            if dut.MARK_WHEN_FULL.value and rx_frame.tuser:
+                continue
+
+            assert not rx_frame.tuser
+
+            assert len(test_frames) > 0
+
+            while True:
+                test_frame = test_frames.pop(0)
+                if rx_frame.tid == test_frame.tid and rx_frame.tdest == test_frame.tdest and rx_frame.tdata == test_frame.tdata:
+                    break
+
+        assert len(test_frames) < 512
+
+    else:
+        for test_frame in test_frames:
+            rx_frame = await tb.sink.recv()
+
+            assert rx_frame.tdata == test_frame.tdata
+            assert rx_frame.tid == test_frame.tid
+            assert rx_frame.tdest == test_frame.tdest
+            assert not rx_frame.tuser
+
+    assert tb.sink.empty()
+
+    await RisingEdge(dut.clk)
+    await RisingEdge(dut.clk)
+
+
+def cycle_pause():
+    return itertools.cycle([1, 1, 1, 0])
+
+
+def size_list():
+    data_width = len(cocotb.top.m_axis.tdata)
+    byte_width = data_width // 8
+    return list(range(1, byte_width*4+1))+[512]+[1]*64
+
+
+def incrementing_payload(length):
+    return bytearray(itertools.islice(itertools.cycle(range(256)), length))
+
+
+if cocotb.SIM_NAME:
+
+    factory = TestFactory(run_test)
+    factory.add_option("payload_lengths", [size_list])
+    factory.add_option("payload_data", [incrementing_payload])
+    factory.add_option("idle_inserter", [None, cycle_pause])
+    factory.add_option("backpressure_inserter", [None, cycle_pause])
+    factory.generate_tests()
+
+    for test in [
+                run_test_tuser_assert,
+                run_test_init_sink_pause,
+                run_test_init_sink_pause_reset,
+                run_test_pause,
+                run_test_overflow,
+                run_test_oversize
+            ]:
+
+        factory = TestFactory(test)
+        factory.generate_tests()
+
+    factory = TestFactory(run_stress_test)
+    factory.add_option("idle_inserter", [None, cycle_pause])
+    factory.add_option("backpressure_inserter", [None, cycle_pause])
+    factory.generate_tests()
+
+
+# cocotb-test
+
+tests_dir = 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(("frame_fifo", "drop_oversize_frame", "drop_bad_frame",
+    "drop_when_full", "mark_when_full"),
+    [(0, 0, 0, 0, 0), (1, 0, 0, 0, 0), (1, 1, 0, 0, 0), (1, 1, 1, 0, 0),
+        (1, 1, 1, 1, 0), (0, 0, 0, 0, 1)])
+@pytest.mark.parametrize(("ram_pipeline", "output_fifo"),
+    [(0, 0), (1, 0), (4, 0), (0, 1), (1, 1), (4, 1)])
+@pytest.mark.parametrize("data_w", [8, 16, 32, 64])
+def test_taxi_axis_fifo(request, data_w, ram_pipeline, output_fifo,
+        frame_fifo, drop_oversize_frame, drop_bad_frame,
+        drop_when_full, mark_when_full):
+
+    dut = "taxi_axis_fifo"
+    module = os.path.splitext(os.path.basename(__file__))[0]
+    toplevel = module
+
+    verilog_sources = [
+        os.path.join(tests_dir, f"{toplevel}.sv"),
+        os.path.join(rtl_dir, "axis", f"{dut}.sv"),
+        os.path.join(rtl_dir, "axis", "taxi_axis_if.sv"),
+    ]
+
+    verilog_sources = process_f_files(verilog_sources)
+
+    parameters = {}
+
+    parameters['DATA_W'] = data_w
+    parameters['KEEP_EN'] = int(parameters['DATA_W'] > 8)
+    parameters['KEEP_W'] = (parameters['DATA_W'] + 7) // 8
+    parameters['STRB_EN'] = 0
+    parameters['DEPTH'] = 1024 * parameters['KEEP_W']
+    parameters['LAST_EN'] = 1
+    parameters['ID_EN'] = 1
+    parameters['ID_W'] = 8
+    parameters['DEST_EN'] = 1
+    parameters['DEST_W'] = 8
+    parameters['USER_EN'] = 1
+    parameters['USER_W'] = 1
+    parameters['RAM_PIPELINE'] = ram_pipeline
+    parameters['OUTPUT_FIFO_EN'] = output_fifo
+    parameters['FRAME_FIFO'] = frame_fifo
+    parameters['USER_BAD_FRAME_VALUE'] = 1
+    parameters['USER_BAD_FRAME_MASK'] = 1
+    parameters['DROP_OVERSIZE_FRAME'] = drop_oversize_frame
+    parameters['DROP_BAD_FRAME'] = drop_bad_frame
+    parameters['DROP_WHEN_FULL'] = drop_when_full
+    parameters['MARK_WHEN_FULL'] = mark_when_full
+    parameters['PAUSE_EN'] = 1
+    parameters['FRAME_PAUSE'] = 1
+
+    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,
+    )