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eth: Add AXI stream 32-bit XGMII Ethernet frame transmitter module and testbench

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Signed-off-by: Alex Forencich <alex@alexforencich.com>
This commit is contained in:
Alex Forencich
2025-02-07 18:03:06 -08:00
parent c914adf9f1
commit a375eb342d
4 changed files with 1045 additions and 0 deletions
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543
rtl/eth/taxi_axis_xgmii_tx_32.sv Normal file
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// SPDX-License-Identifier: CERN-OHL-S-2.0
/*
Copyright (c) 2015-2025 FPGA Ninja, LLC
Authors:
- Alex Forencich
*/
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* AXI4-Stream XGMII frame transmitter (AXI in, XGMII out)
*/
module taxi_axis_xgmii_tx_32 #
(
parameter DATA_W = 32,
parameter CTRL_W = (DATA_W/8),
parameter logic PADDING_EN = 1'b1,
parameter logic DIC_EN = 1'b1,
parameter MIN_FRAME_LEN = 64,
parameter logic PTP_TS_EN = 1'b0,
parameter PTP_TS_W = 96,
parameter logic TX_CPL_CTRL_IN_TUSER = 1'b1
)
(
input wire logic clk,
input wire logic rst,
/*
* Transmit interface (AXI stream)
*/
taxi_axis_if.snk s_axis_tx,
taxi_axis_if.src m_axis_tx_cpl,
/*
* XGMII output
*/
output wire logic [DATA_W-1:0] xgmii_txd,
output wire logic [CTRL_W-1:0] xgmii_txc,
/*
* PTP
*/
input wire logic [PTP_TS_W-1:0] ptp_ts,
/*
* Configuration
*/
input wire logic [7:0] cfg_ifg,
input wire logic cfg_tx_enable,
/*
* Status
*/
output wire logic start_packet,
output wire logic error_underflow
);
// extract parameters
localparam KEEP_W = DATA_W/8;
localparam USER_W = TX_CPL_CTRL_IN_TUSER ? 2 : 1;
localparam TX_TAG_W = s_axis_tx.ID_W;
localparam EMPTY_W = $clog2(KEEP_W);
localparam MIN_LEN_W = $clog2(MIN_FRAME_LEN-4-CTRL_W+1);
// check configuration
if (DATA_W != 32)
$fatal(0, "Error: Interface width must be 32 (instance %m)");
if (KEEP_W*8 != DATA_W || CTRL_W*8 != DATA_W)
$fatal(0, "Error: Interface requires byte (8-bit) granularity (instance %m)");
if (s_axis_tx.DATA_W != DATA_W)
$fatal(0, "Error: Interface DATA_W parameter mismatch (instance %m)");
if (s_axis_tx.USER_W != USER_W)
$fatal(0, "Error: Interface USER_W parameter mismatch (instance %m)");
localparam [7:0]
ETH_PRE = 8'h55,
ETH_SFD = 8'hD5;
localparam [7:0]
XGMII_IDLE = 8'h07,
XGMII_START = 8'hfb,
XGMII_TERM = 8'hfd,
XGMII_ERROR = 8'hfe;
localparam [3:0]
STATE_IDLE = 4'd0,
STATE_PREAMBLE = 4'd1,
STATE_PAYLOAD = 4'd2,
STATE_PAD = 4'd3,
STATE_FCS_1 = 4'd4,
STATE_FCS_2 = 4'd5,
STATE_FCS_3 = 4'd6,
STATE_ERR = 4'd7,
STATE_IFG = 4'd8;
logic [3:0] state_reg = STATE_IDLE, state_next;
// datapath control signals
logic reset_crc;
logic update_crc;
logic [DATA_W-1:0] s_tdata_reg = '0, s_tdata_next;
logic [EMPTY_W-1:0] s_empty_reg = '0, s_empty_next;
logic [DATA_W-1:0] fcs_output_txd_0;
logic [DATA_W-1:0] fcs_output_txd_1;
logic [CTRL_W-1:0] fcs_output_txc_0;
logic [CTRL_W-1:0] fcs_output_txc_1;
logic [7:0] ifg_offset;
logic extra_cycle;
logic frame_reg = 1'b0, frame_next;
logic frame_error_reg = 1'b0, frame_error_next;
logic [MIN_LEN_W-1:0] frame_min_count_reg = '0, frame_min_count_next;
logic [7:0] ifg_count_reg = 8'd0, ifg_count_next;
logic [1:0] deficit_idle_count_reg = 2'd0, deficit_idle_count_next;
logic s_axis_tx_tready_reg = 1'b0, s_axis_tx_tready_next;
logic [PTP_TS_W-1:0] m_axis_tx_cpl_ts_reg = '0, m_axis_tx_cpl_ts_next;
logic [TX_TAG_W-1:0] m_axis_tx_cpl_tag_reg = '0, m_axis_tx_cpl_tag_next;
logic m_axis_tx_cpl_valid_reg = 1'b0, m_axis_tx_cpl_valid_next;
logic [31:0] crc_state_reg[3:0];
wire [31:0] crc_state_next[3:0];
logic [DATA_W-1:0] xgmii_txd_reg = {CTRL_W{XGMII_IDLE}}, xgmii_txd_next;
logic [CTRL_W-1:0] xgmii_txc_reg = {CTRL_W{1'b1}}, xgmii_txc_next;
logic start_packet_reg = 1'b0, start_packet_next;
logic error_underflow_reg = 1'b0, error_underflow_next;
assign s_axis_tx.tready = s_axis_tx_tready_reg;
assign xgmii_txd = xgmii_txd_reg;
assign xgmii_txc = xgmii_txc_reg;
assign m_axis_tx_cpl.tdata = PTP_TS_EN ? m_axis_tx_cpl_ts_reg : '0;
assign m_axis_tx_cpl.tkeep = 1'b1;
assign m_axis_tx_cpl.tstrb = m_axis_tx_cpl.tkeep;
assign m_axis_tx_cpl.tvalid = m_axis_tx_cpl_valid_reg;
assign m_axis_tx_cpl.tlast = 1'b1;
assign m_axis_tx_cpl.tid = m_axis_tx_cpl_tag_reg;
assign m_axis_tx_cpl.tdest = '0;
assign m_axis_tx_cpl.tuser = '0;
assign start_packet = start_packet_reg;
assign error_underflow = error_underflow_reg;
for (genvar n = 0; n < 4; n = n + 1) begin : crc
taxi_lfsr #(
.LFSR_W(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_GALOIS(1),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_W(8*(n+1))
)
eth_crc (
.data_in(s_tdata_reg[0 +: 8*(n+1)]),
.state_in(crc_state_reg[3]),
.data_out(),
.state_out(crc_state_next[n])
);
end
function [1:0] keep2empty;
input [3:0] k;
casez (k)
4'bzzz0: keep2empty = 2'd3;
4'bzz01: keep2empty = 2'd3;
4'bz011: keep2empty = 2'd2;
4'b0111: keep2empty = 2'd1;
4'b1111: keep2empty = 2'd0;
endcase
endfunction
// Mask input data
wire [DATA_W-1:0] s_axis_tx_tdata_masked;
for (genvar n = 0; n < CTRL_W; n = n + 1) begin
assign s_axis_tx_tdata_masked[n*8 +: 8] = s_axis_tx.tkeep[n] ? s_axis_tx.tdata[n*8 +: 8] : 8'd0;
end
// FCS cycle calculation
always_comb begin
casez (s_empty_reg)
2'd3: begin
fcs_output_txd_0 = {~crc_state_next[0][23:0], s_tdata_reg[7:0]};
fcs_output_txd_1 = {{2{XGMII_IDLE}}, XGMII_TERM, ~crc_state_reg[0][31:24]};
fcs_output_txc_0 = 4'b0000;
fcs_output_txc_1 = 4'b1110;
ifg_offset = 8'd3;
extra_cycle = 1'b0;
end
2'd2: begin
fcs_output_txd_0 = {~crc_state_next[1][15:0], s_tdata_reg[15:0]};
fcs_output_txd_1 = {XGMII_IDLE, XGMII_TERM, ~crc_state_reg[1][31:16]};
fcs_output_txc_0 = 4'b0000;
fcs_output_txc_1 = 4'b1100;
ifg_offset = 8'd2;
extra_cycle = 1'b0;
end
2'd1: begin
fcs_output_txd_0 = {~crc_state_next[2][7:0], s_tdata_reg[23:0]};
fcs_output_txd_1 = {XGMII_TERM, ~crc_state_reg[2][31:8]};
fcs_output_txc_0 = 4'b0000;
fcs_output_txc_1 = 4'b1000;
ifg_offset = 8'd1;
extra_cycle = 1'b0;
end
2'd0: begin
fcs_output_txd_0 = s_tdata_reg;
fcs_output_txd_1 = ~crc_state_reg[3];
fcs_output_txc_0 = 4'b0000;
fcs_output_txc_1 = 4'b0000;
ifg_offset = 8'd4;
extra_cycle = 1'b1;
end
endcase
end
always_comb begin
state_next = STATE_IDLE;
reset_crc = 1'b0;
update_crc = 1'b0;
frame_next = frame_reg;
frame_error_next = frame_error_reg;
frame_min_count_next = frame_min_count_reg;
ifg_count_next = ifg_count_reg;
deficit_idle_count_next = deficit_idle_count_reg;
s_axis_tx_tready_next = 1'b0;
s_tdata_next = s_tdata_reg;
s_empty_next = s_empty_reg;
m_axis_tx_cpl_ts_next = m_axis_tx_cpl_ts_reg;
m_axis_tx_cpl_tag_next = m_axis_tx_cpl_tag_reg;
m_axis_tx_cpl_valid_next = 1'b0;
if (start_packet_reg) begin
if (PTP_TS_EN) begin
m_axis_tx_cpl_ts_next = ptp_ts;
end
m_axis_tx_cpl_tag_next = s_axis_tx.tid;
if (TX_CPL_CTRL_IN_TUSER) begin
m_axis_tx_cpl_valid_next = (s_axis_tx.tuser >> 1) != 0;
end else begin
m_axis_tx_cpl_valid_next = 1'b1;
end
end
// XGMII idle
xgmii_txd_next = {CTRL_W{XGMII_IDLE}};
xgmii_txc_next = {CTRL_W{1'b1}};
start_packet_next = 1'b0;
error_underflow_next = 1'b0;
if (s_axis_tx.tvalid && s_axis_tx.tready) begin
frame_next = !s_axis_tx.tlast;
end
case (state_reg)
STATE_IDLE: begin
// idle state - wait for data
frame_error_next = 1'b0;
frame_min_count_next = MIN_LEN_W'(MIN_FRAME_LEN-4-CTRL_W);
reset_crc = 1'b1;
// XGMII idle
xgmii_txd_next = {CTRL_W{XGMII_IDLE}};
xgmii_txc_next = {CTRL_W{1'b1}};
s_tdata_next = s_axis_tx_tdata_masked;
s_empty_next = keep2empty(s_axis_tx.tkeep);
if (s_axis_tx.tvalid && cfg_tx_enable) begin
// XGMII start and preamble
xgmii_txd_next = {{3{ETH_PRE}}, XGMII_START};
xgmii_txc_next = 4'b0001;
s_axis_tx_tready_next = 1'b1;
state_next = STATE_PREAMBLE;
end else begin
ifg_count_next = 8'd0;
deficit_idle_count_next = 2'd0;
state_next = STATE_IDLE;
end
end
STATE_PREAMBLE: begin
// send preamble
reset_crc = 1'b1;
s_tdata_next = s_axis_tx_tdata_masked;
s_empty_next = keep2empty(s_axis_tx.tkeep);
xgmii_txd_next = {ETH_SFD, {3{ETH_PRE}}};
xgmii_txc_next = {CTRL_W{1'b0}};
s_axis_tx_tready_next = 1'b1;
start_packet_next = 1'b1;
state_next = STATE_PAYLOAD;
end
STATE_PAYLOAD: begin
// transfer payload
update_crc = 1'b1;
s_axis_tx_tready_next = 1'b1;
if (frame_min_count_reg > MIN_LEN_W'(CTRL_W)) begin
frame_min_count_next = MIN_LEN_W'(frame_min_count_reg - CTRL_W);
end else begin
frame_min_count_next = 0;
end
xgmii_txd_next = s_tdata_reg;
xgmii_txc_next = {CTRL_W{1'b0}};
s_tdata_next = s_axis_tx_tdata_masked;
s_empty_next = keep2empty(s_axis_tx.tkeep);
if (!s_axis_tx.tvalid || s_axis_tx.tlast) begin
s_axis_tx_tready_next = frame_next; // drop frame
frame_error_next = !s_axis_tx.tvalid || s_axis_tx.tuser[0];
error_underflow_next = !s_axis_tx.tvalid;
if (PADDING_EN && frame_min_count_reg != 0) begin
if (frame_min_count_reg > MIN_LEN_W'(CTRL_W)) begin
s_empty_next = 0;
state_next = STATE_PAD;
end else begin
if (keep2empty(s_axis_tx.tkeep) > 2'(CTRL_W-frame_min_count_reg)) begin
s_empty_next = 2'(CTRL_W-frame_min_count_reg);
end
state_next = STATE_FCS_1;
end
end else begin
state_next = STATE_FCS_1;
end
end else begin
state_next = STATE_PAYLOAD;
end
end
STATE_PAD: begin
// pad frame to MIN_FRAME_LEN
s_axis_tx_tready_next = frame_next; // drop frame
xgmii_txd_next = s_tdata_reg;
xgmii_txc_next = {CTRL_W{1'b0}};
s_tdata_next = 32'd0;
s_empty_next = 0;
update_crc = 1'b1;
if (frame_min_count_reg > MIN_LEN_W'(CTRL_W)) begin
frame_min_count_next = MIN_LEN_W'(frame_min_count_reg - CTRL_W);
state_next = STATE_PAD;
end else begin
frame_min_count_next = 0;
s_empty_next = 2'(CTRL_W-frame_min_count_reg);
state_next = STATE_FCS_1;
end
end
STATE_FCS_1: begin
// last cycle
s_axis_tx_tready_next = frame_next; // drop frame
xgmii_txd_next = fcs_output_txd_0;
xgmii_txc_next = fcs_output_txc_0;
update_crc = 1'b1;
ifg_count_next = (cfg_ifg > 8'd12 ? cfg_ifg : 8'd12) - ifg_offset + 8'(deficit_idle_count_reg);
if (frame_error_reg) begin
state_next = STATE_ERR;
end else begin
state_next = STATE_FCS_2;
end
end
STATE_FCS_2: begin
// last cycle
s_axis_tx_tready_next = frame_next; // drop frame
xgmii_txd_next = fcs_output_txd_1;
xgmii_txc_next = fcs_output_txc_1;
if (extra_cycle) begin
state_next = STATE_FCS_3;
end else begin
state_next = STATE_IFG;
end
end
STATE_FCS_3: begin
// last cycle
s_axis_tx_tready_next = frame_next; // drop frame
xgmii_txd_next = {{3{XGMII_IDLE}}, XGMII_TERM};
xgmii_txc_next = {CTRL_W{1'b1}};
if (DIC_EN) begin
if (ifg_count_next > 8'd3) begin
state_next = STATE_IFG;
end else begin
deficit_idle_count_next = 2'(ifg_count_next);
ifg_count_next = 8'd0;
s_axis_tx_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end else begin
if (ifg_count_next > 8'd0) begin
state_next = STATE_IFG;
end else begin
state_next = STATE_IDLE;
end
end
end
STATE_ERR: begin
// terminate packet with error
s_axis_tx_tready_next = frame_next; // drop frame
// XGMII error
xgmii_txd_next = {XGMII_TERM, {3{XGMII_ERROR}}};
xgmii_txc_next = {CTRL_W{1'b1}};
ifg_count_next = cfg_ifg > 8'd12 ? cfg_ifg : 8'd12;
state_next = STATE_IFG;
end
STATE_IFG: begin
// send IFG
s_axis_tx_tready_next = frame_next; // drop frame
// XGMII idle
xgmii_txd_next = {CTRL_W{XGMII_IDLE}};
xgmii_txc_next = {CTRL_W{1'b1}};
if (ifg_count_reg > 8'd4) begin
ifg_count_next = ifg_count_reg - 8'd4;
end else begin
ifg_count_next = 8'd0;
end
if (DIC_EN) begin
if (ifg_count_next > 8'd3 || frame_reg) begin
state_next = STATE_IFG;
end else begin
deficit_idle_count_next = 2'(ifg_count_next);
ifg_count_next = 8'd0;
state_next = STATE_IDLE;
end
end else begin
if (ifg_count_next > 8'd0 || frame_reg) begin
state_next = STATE_IFG;
end else begin
state_next = STATE_IDLE;
end
end
end
default: begin
// invalid state, return to idle
state_next = STATE_IDLE;
end
endcase
end
always_ff @(posedge clk) begin
state_reg <= state_next;
frame_reg <= frame_next;
frame_error_reg <= frame_error_next;
frame_min_count_reg <= frame_min_count_next;
ifg_count_reg <= ifg_count_next;
deficit_idle_count_reg <= deficit_idle_count_next;
s_tdata_reg <= s_tdata_next;
s_empty_reg <= s_empty_next;
s_axis_tx_tready_reg <= s_axis_tx_tready_next;
m_axis_tx_cpl_ts_reg <= m_axis_tx_cpl_ts_next;
m_axis_tx_cpl_tag_reg <= m_axis_tx_cpl_tag_next;
m_axis_tx_cpl_valid_reg <= m_axis_tx_cpl_valid_next;
for (integer i = 0; i < 3; i = i + 1) begin
crc_state_reg[i] <= crc_state_next[i];
end
if (update_crc) begin
crc_state_reg[3] <= crc_state_next[3];
end
if (reset_crc) begin
crc_state_reg[3] <= '1;
end
xgmii_txd_reg <= xgmii_txd_next;
xgmii_txc_reg <= xgmii_txc_next;
start_packet_reg <= start_packet_next;
error_underflow_reg <= error_underflow_next;
if (rst) begin
state_reg <= STATE_IDLE;
frame_reg <= 1'b0;
ifg_count_reg <= 8'd0;
deficit_idle_count_reg <= 2'd0;
s_axis_tx_tready_reg <= 1'b0;
m_axis_tx_cpl_valid_reg <= 1'b0;
xgmii_txd_reg <= {CTRL_W{XGMII_IDLE}};
xgmii_txc_reg <= {CTRL_W{1'b1}};
start_packet_reg <= 1'b0;
error_underflow_reg <= 1'b0;
end
end
endmodule
`resetall

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tb/eth/taxi_axis_xgmii_tx_32/Makefile Normal file
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# SPDX-License-Identifier: CERN-OHL-S-2.0
#
# Copyright (c) 2020-2025 FPGA Ninja, LLC
#
# Authors:
# - Alex Forencich
TOPLEVEL_LANG = verilog
SIM ?= verilator
WAVES ?= 0
COCOTB_HDL_TIMEUNIT = 1ns
COCOTB_HDL_TIMEPRECISION = 1ps
DUT = taxi_axis_xgmii_tx_32
COCOTB_TEST_MODULES = test_$(DUT)
COCOTB_TOPLEVEL = test_$(DUT)
MODULE = $(COCOTB_TEST_MODULES)
TOPLEVEL = $(COCOTB_TOPLEVEL)
VERILOG_SOURCES += $(COCOTB_TOPLEVEL).sv
VERILOG_SOURCES += ../../../rtl/eth/$(DUT).sv
VERILOG_SOURCES += ../../../rtl/lfsr/taxi_lfsr.sv
VERILOG_SOURCES += ../../../rtl/axis/taxi_axis_if.sv
# handle file list files
process_f_file = $(call process_f_files,$(addprefix $(dir $1),$(shell cat $1)))
process_f_files = $(foreach f,$1,$(if $(filter %.f,$f),$(call process_f_file,$f),$f))
uniq_base = $(if $1,$(call uniq_base,$(foreach f,$1,$(if $(filter-out $(notdir $(lastword $1)),$(notdir $f)),$f,))) $(lastword $1))
VERILOG_SOURCES := $(call uniq_base,$(call process_f_files,$(VERILOG_SOURCES)))
# module parameters
export PARAM_DATA_W := 32
export PARAM_CTRL_W := $(shell expr $(PARAM_DATA_W) / 8 )
export PARAM_PADDING_EN := 1
export PARAM_DIC_EN := 1
export PARAM_MIN_FRAME_LEN := 64
export PARAM_PTP_TS_EN := 1
export PARAM_PTP_TS_W := 96
export PARAM_TX_TAG_W := 16
export PARAM_TX_CPL_CTRL_IN_TUSER := 1
ifeq ($(SIM), icarus)
PLUSARGS += -fst
COMPILE_ARGS += $(foreach v,$(filter PARAM_%,$(.VARIABLES)),-P $(COCOTB_TOPLEVEL).$(subst PARAM_,,$(v))=$($(v)))
else ifeq ($(SIM), verilator)
COMPILE_ARGS += $(foreach v,$(filter PARAM_%,$(.VARIABLES)),-G$(subst PARAM_,,$(v))=$($(v)))
ifeq ($(WAVES), 1)
COMPILE_ARGS += --trace-fst
VERILATOR_TRACE = 1
endif
endif
include $(shell cocotb-config --makefiles)/Makefile.sim

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tb/eth/taxi_axis_xgmii_tx_32/test_taxi_axis_xgmii_tx_32.py Normal file
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#!/usr/bin/env python
# SPDX-License-Identifier: CERN-OHL-S-2.0
"""
Copyright (c) 2020-2025 FPGA Ninja, LLC
Authors:
- Alex Forencich
"""
import itertools
import logging
import os
import cocotb_test.simulator
import pytest
import cocotb
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge
from cocotb.utils import get_time_from_sim_steps
from cocotb.regression import TestFactory
from cocotbext.eth import XgmiiSink, PtpClockSimTime
from cocotbext.axi import AxiStreamBus, AxiStreamSource, AxiStreamSink, AxiStreamFrame
class TB:
def __init__(self, dut):
self.dut = dut
self.log = logging.getLogger("cocotb.tb")
self.log.setLevel(logging.DEBUG)
cocotb.start_soon(Clock(dut.clk, 3.2, units="ns").start())
self.source = AxiStreamSource(AxiStreamBus.from_entity(dut.s_axis_tx), dut.clk, dut.rst)
self.sink = XgmiiSink(dut.xgmii_txd, dut.xgmii_txc, dut.clk, dut.rst)
self.ptp_clock = PtpClockSimTime(ts_tod=dut.ptp_ts, clock=dut.clk)
self.tx_cpl_sink = AxiStreamSink(AxiStreamBus.from_entity(dut.m_axis_tx_cpl), dut.clk, dut.rst)
dut.cfg_ifg.setimmediatevalue(0)
dut.cfg_tx_enable.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)
async def run_test(dut, payload_lengths=None, payload_data=None, ifg=12):
tb = TB(dut)
tb.dut.cfg_ifg.value = ifg
tb.dut.cfg_tx_enable.value = 1
await tb.reset()
test_frames = [payload_data(x) for x in payload_lengths()]
for test_data in test_frames:
await tb.source.send(AxiStreamFrame(test_data, tid=0, tuser=2))
for test_data in test_frames:
rx_frame = await tb.sink.recv()
tx_cpl = await tb.tx_cpl_sink.recv()
ptp_ts_ns = int(tx_cpl.tdata[0]) / 2**16
rx_frame_sfd_ns = get_time_from_sim_steps(rx_frame.sim_time_sfd, "ns")
tb.log.info("TX frame PTP TS: %f ns", ptp_ts_ns)
tb.log.info("RX frame SFD sim time: %f ns", rx_frame_sfd_ns)
tb.log.info("Difference: %f ns", abs(rx_frame_sfd_ns - ptp_ts_ns))
assert rx_frame.get_payload() == test_data
assert rx_frame.check_fcs()
assert rx_frame.ctrl is None
assert abs(rx_frame_sfd_ns - ptp_ts_ns - 3.2) < 0.01
assert tb.sink.empty()
await RisingEdge(dut.clk)
await RisingEdge(dut.clk)
async def run_test_alignment(dut, payload_data=None, ifg=12):
enable_dic = int(dut.DIC_EN.value)
tb = TB(dut)
byte_width = tb.source.width // 8
tb.dut.cfg_ifg.value = ifg
tb.dut.cfg_tx_enable.value = 1
await tb.reset()
for length in range(60, 92):
for k in range(10):
await RisingEdge(dut.clk)
test_frames = [payload_data(length) for k in range(10)]
start_lane = []
for test_data in test_frames:
await tb.source.send(AxiStreamFrame(test_data, tid=0, tuser=2))
for test_data in test_frames:
rx_frame = await tb.sink.recv()
tx_cpl = await tb.tx_cpl_sink.recv()
ptp_ts_ns = int(tx_cpl.tdata[0]) / 2**16
rx_frame_sfd_ns = get_time_from_sim_steps(rx_frame.sim_time_sfd, "ns")
tb.log.info("TX frame PTP TS: %f ns", ptp_ts_ns)
tb.log.info("RX frame SFD sim time: %f ns", rx_frame_sfd_ns)
tb.log.info("Difference: %f ns", abs(rx_frame_sfd_ns - ptp_ts_ns))
assert rx_frame.get_payload() == test_data
assert rx_frame.check_fcs()
assert rx_frame.ctrl is None
assert abs(rx_frame_sfd_ns - ptp_ts_ns - 3.2) < 0.01
start_lane.append(rx_frame.start_lane)
tb.log.info("length: %d", length)
tb.log.info("start_lane: %s", start_lane)
start_lane_ref = []
# compute expected starting lanes
lane = 0
deficit_idle_count = 0
for test_data in test_frames:
if ifg == 0:
lane = 0
start_lane_ref.append(lane)
lane = (lane + len(test_data)+4+ifg) % byte_width
if enable_dic:
offset = lane % 4
if deficit_idle_count+offset >= 4:
offset += 4
lane = (lane - offset) % byte_width
deficit_idle_count = (deficit_idle_count + offset) % 4
else:
offset = lane % 4
if offset > 0:
offset += 4
lane = (lane - offset) % byte_width
tb.log.info("start_lane_ref: %s", start_lane_ref)
assert start_lane_ref == start_lane
await RisingEdge(dut.clk)
assert tb.sink.empty()
await RisingEdge(dut.clk)
await RisingEdge(dut.clk)
async def run_test_underrun(dut, ifg=12):
tb = TB(dut)
tb.dut.cfg_ifg.value = ifg
tb.dut.cfg_tx_enable.value = 1
await tb.reset()
test_data = bytes(x for x in range(60))
for k in range(3):
test_frame = AxiStreamFrame(test_data)
await tb.source.send(test_frame)
for k in range(32):
await RisingEdge(dut.clk)
tb.source.pause = True
for k in range(4):
await RisingEdge(dut.clk)
tb.source.pause = False
for k in range(3):
rx_frame = await tb.sink.recv()
if k == 1:
assert rx_frame.data[-1] == 0xFE
assert rx_frame.ctrl[-1] == 1
else:
assert rx_frame.get_payload() == test_data
assert rx_frame.check_fcs()
assert rx_frame.ctrl is None
assert tb.sink.empty()
await RisingEdge(dut.clk)
await RisingEdge(dut.clk)
async def run_test_error(dut, ifg=12):
tb = TB(dut)
tb.dut.cfg_ifg.value = ifg
tb.dut.cfg_tx_enable.value = 1
await tb.reset()
test_data = bytes(x for x in range(60))
for k in range(3):
test_frame = AxiStreamFrame(test_data)
if k == 1:
test_frame.tuser = 1
await tb.source.send(test_frame)
for k in range(3):
rx_frame = await tb.sink.recv()
if k == 1:
assert rx_frame.data[-1] == 0xFE
assert rx_frame.ctrl[-1] == 1
else:
assert rx_frame.get_payload() == test_data
assert rx_frame.check_fcs()
assert rx_frame.ctrl is None
assert tb.sink.empty()
await RisingEdge(dut.clk)
await RisingEdge(dut.clk)
def size_list():
return list(range(60, 128)) + [512, 1514, 9214] + [60]*10
def incrementing_payload(length):
return bytearray(itertools.islice(itertools.cycle(range(256)), length))
def cycle_en():
return itertools.cycle([0, 0, 0, 1])
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("ifg", [12])
factory.generate_tests()
factory = TestFactory(run_test_alignment)
factory.add_option("payload_data", [incrementing_payload])
factory.add_option("ifg", [12])
factory.generate_tests()
for test in [run_test_underrun, run_test_error]:
factory = TestFactory(test)
factory.add_option("ifg", [12])
factory.generate_tests()
# 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("dic_en", [1, 0])
def test_taxi_axis_xgmii_tx_32(request, dic_en):
dut = "taxi_axis_xgmii_tx_32"
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, "eth", f"{dut}.sv"),
os.path.join(rtl_dir, "lfsr", "taxi_lfsr.sv"),
os.path.join(rtl_dir, "axis", "taxi_axis_if.sv"),
]
verilog_sources = process_f_files(verilog_sources)
parameters = {}
parameters['DATA_W'] = 32
parameters['CTRL_W'] = parameters['DATA_W'] // 8
parameters['PADDING_EN'] = 1
parameters['DIC_EN'] = dic_en
parameters['MIN_FRAME_LEN'] = 64
parameters['PTP_TS_EN'] = 1
parameters['PTP_TS_W'] = 96
parameters['TX_TAG_W'] = 16
parameters['TX_CPL_CTRL_IN_TUSER'] = 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,
)

99
tb/eth/taxi_axis_xgmii_tx_32/test_taxi_axis_xgmii_tx_32.sv Normal file
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// SPDX-License-Identifier: CERN-OHL-S-2.0
/*
Copyright (c) 2025 FPGA Ninja, LLC
Authors:
- Alex Forencich
*/
`resetall
`timescale 1ns / 1ps
`default_nettype none
/*
* AXI4-Stream XGMII frame transmitter testbench
*/
module test_taxi_axis_xgmii_tx_32 #
(
/* verilator lint_off WIDTHTRUNC */
parameter DATA_W = 32,
parameter CTRL_W = (DATA_W/8),
parameter logic PADDING_EN = 1'b1,
parameter logic DIC_EN = 1'b1,
parameter MIN_FRAME_LEN = 64,
parameter logic PTP_TS_EN = 1'b0,
parameter PTP_TS_W = 96,
parameter TX_TAG_W = 16,
parameter logic TX_CPL_CTRL_IN_TUSER = 1'b0
/* verilator lint_on WIDTHTRUNC */
)
();
localparam USER_W = TX_CPL_CTRL_IN_TUSER ? 2 : 1;
logic clk;
logic rst;
taxi_axis_if #(.DATA_W(DATA_W), .USER_W(USER_W), .ID_EN(1), .ID_W(TX_TAG_W)) s_axis_tx();
taxi_axis_if #(.DATA_W(PTP_TS_W), .KEEP_W(1), .ID_EN(1), .ID_W(TX_TAG_W)) m_axis_tx_cpl();
logic [DATA_W-1:0] xgmii_txd;
logic [CTRL_W-1:0] xgmii_txc;
logic [PTP_TS_W-1:0] ptp_ts;
logic [7:0] cfg_ifg;
logic cfg_tx_enable;
logic start_packet;
logic error_underflow;
taxi_axis_xgmii_tx_32 #(
.DATA_W(DATA_W),
.CTRL_W(CTRL_W),
.PADDING_EN(PADDING_EN),
.DIC_EN(DIC_EN),
.MIN_FRAME_LEN(MIN_FRAME_LEN),
.PTP_TS_EN(PTP_TS_EN),
.PTP_TS_W(PTP_TS_W),
.TX_CPL_CTRL_IN_TUSER(TX_CPL_CTRL_IN_TUSER)
)
uut (
.clk(clk),
.rst(rst),
/*
* AXI4-Stream input (sink)
*/
.s_axis_tx(s_axis_tx),
.m_axis_tx_cpl(m_axis_tx_cpl),
/*
* XGMII output
*/
.xgmii_txd(xgmii_txd),
.xgmii_txc(xgmii_txc),
/*
* PTP
*/
.ptp_ts(ptp_ts),
/*
* Configuration
*/
.cfg_ifg(cfg_ifg),
.cfg_tx_enable(cfg_tx_enable),
/*
* Status
*/
.start_packet(start_packet),
.error_underflow(error_underflow)
);
endmodule
`resetall