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verilog-ethernet/rtl/axis_xgmii_tx_64.v
Alex Forencich 9ae60dcd9a Simplify lane swapping code
2019-01-22 14:22:01 -08:00

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19 KiB
Verilog
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/*
Copyright (c) 2015-2017 Alex Forencich
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
// Language: Verilog 2001
`timescale 1ns / 1ps
/*
* AXI4-Stream XGMII frame transmitter (AXI in, XGMII out)
*/
module axis_xgmii_tx_64 #
(
parameter ENABLE_PADDING = 1,
parameter ENABLE_DIC = 1,
parameter MIN_FRAME_LENGTH = 64
)
(
input wire clk,
input wire rst,
/*
* AXI input
*/
input wire [63:0] s_axis_tdata,
input wire [7:0] s_axis_tkeep,
input wire s_axis_tvalid,
output wire s_axis_tready,
input wire s_axis_tlast,
input wire s_axis_tuser,
/*
* XGMII output
*/
output wire [63:0] xgmii_txd,
output wire [7:0] xgmii_txc,
/*
* Configuration
*/
input wire [7:0] ifg_delay
);
localparam MIN_FL_NOCRC = MIN_FRAME_LENGTH-4;
localparam MIN_FL_NOCRC_MS = MIN_FL_NOCRC & 16'hfff8;
localparam MIN_FL_NOCRC_LS = MIN_FL_NOCRC & 16'h0007;
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 [2:0]
STATE_IDLE = 3'd0,
STATE_PAYLOAD = 3'd1,
STATE_PAD = 3'd2,
STATE_FCS_1 = 3'd3,
STATE_FCS_2 = 3'd4,
STATE_IFG = 3'd5,
STATE_WAIT_END = 3'd6;
reg [2:0] state_reg = STATE_IDLE, state_next;
// datapath control signals
reg reset_crc;
reg update_crc;
reg swap_lanes;
reg unswap_lanes;
reg lanes_swapped = 1'b0;
reg [31:0] swap_txd = 32'd0;
reg [3:0] swap_txc = 4'd0;
reg [63:0] s_axis_tdata_masked;
reg [63:0] s_tdata_reg = 64'd0, s_tdata_next;
reg [7:0] s_tkeep_reg = 8'd0, s_tkeep_next;
reg [63:0] fcs_output_txd_0;
reg [63:0] fcs_output_txd_1;
reg [7:0] fcs_output_txc_0;
reg [7:0] fcs_output_txc_1;
reg [7:0] ifg_offset;
reg extra_cycle;
reg [15:0] frame_ptr_reg = 16'd0, frame_ptr_next;
reg [7:0] ifg_count_reg = 8'd0, ifg_count_next;
reg [1:0] deficit_idle_count_reg = 2'd0, deficit_idle_count_next;
reg s_axis_tready_reg = 1'b0, s_axis_tready_next;
reg [31:0] crc_state = 32'hFFFFFFFF;
wire [31:0] crc_next0;
wire [31:0] crc_next1;
wire [31:0] crc_next2;
wire [31:0] crc_next3;
wire [31:0] crc_next4;
wire [31:0] crc_next5;
wire [31:0] crc_next6;
wire [31:0] crc_next7;
reg [63:0] xgmii_txd_reg = {8{XGMII_IDLE}}, xgmii_txd_next;
reg [7:0] xgmii_txc_reg = 8'b11111111, xgmii_txc_next;
assign s_axis_tready = s_axis_tready_reg;
assign xgmii_txd = xgmii_txd_reg;
assign xgmii_txc = xgmii_txc_reg;
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(8),
.STYLE("AUTO")
)
eth_crc_8 (
.data_in(s_tdata_reg[7:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next0)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(16),
.STYLE("AUTO")
)
eth_crc_16 (
.data_in(s_tdata_reg[15:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next1)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(24),
.STYLE("AUTO")
)
eth_crc_24 (
.data_in(s_tdata_reg[23:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next2)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(32),
.STYLE("AUTO")
)
eth_crc_32 (
.data_in(s_tdata_reg[31:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next3)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(40),
.STYLE("AUTO")
)
eth_crc_40 (
.data_in(s_tdata_reg[39:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next4)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(48),
.STYLE("AUTO")
)
eth_crc_48 (
.data_in(s_tdata_reg[47:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next5)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(56),
.STYLE("AUTO")
)
eth_crc_56 (
.data_in(s_tdata_reg[55:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next6)
);
lfsr #(
.LFSR_WIDTH(32),
.LFSR_POLY(32'h4c11db7),
.LFSR_CONFIG("GALOIS"),
.LFSR_FEED_FORWARD(0),
.REVERSE(1),
.DATA_WIDTH(64),
.STYLE("AUTO")
)
eth_crc_64 (
.data_in(s_tdata_reg[63:0]),
.state_in(crc_state),
.data_out(),
.state_out(crc_next7)
);
function [3:0] keep2count;
input [7:0] k;
casez (k)
8'bzzzzzzz0: keep2count = 4'd0;
8'bzzzzzz01: keep2count = 4'd1;
8'bzzzzz011: keep2count = 4'd2;
8'bzzzz0111: keep2count = 4'd3;
8'bzzz01111: keep2count = 4'd4;
8'bzz011111: keep2count = 4'd5;
8'bz0111111: keep2count = 4'd6;
8'b01111111: keep2count = 4'd7;
8'b11111111: keep2count = 4'd8;
endcase
endfunction
// Mask input data
integer j;
always @* begin
for (j = 0; j < 8; j = j + 1) begin
s_axis_tdata_masked[j*8 +: 8] = s_axis_tkeep[j] ? s_axis_tdata[j*8 +: 8] : 8'd0;
end
end
// FCS cycle calculation
always @* begin
casez (s_tkeep_reg)
8'bzzzzzz01: begin
fcs_output_txd_0 = {{2{XGMII_IDLE}}, XGMII_TERM, ~crc_next0[31:0], s_tdata_reg[7:0]};
fcs_output_txd_1 = {8{XGMII_IDLE}};
fcs_output_txc_0 = 8'b11100000;
fcs_output_txc_1 = 8'b11111111;
ifg_offset = 8'd3;
extra_cycle = 1'b0;
end
8'bzzzzz011: begin
fcs_output_txd_0 = {XGMII_IDLE, XGMII_TERM, ~crc_next1[31:0], s_tdata_reg[15:0]};
fcs_output_txd_1 = {8{XGMII_IDLE}};
fcs_output_txc_0 = 8'b11000000;
fcs_output_txc_1 = 8'b11111111;
ifg_offset = 8'd2;
extra_cycle = 1'b0;
end
8'bzzzz0111: begin
fcs_output_txd_0 = {XGMII_TERM, ~crc_next2[31:0], s_tdata_reg[23:0]};
fcs_output_txd_1 = {8{XGMII_IDLE}};
fcs_output_txc_0 = 8'b10000000;
fcs_output_txc_1 = 8'b11111111;
ifg_offset = 8'd1;
extra_cycle = 1'b0;
end
8'bzzz01111: begin
fcs_output_txd_0 = {~crc_next3[31:0], s_tdata_reg[31:0]};
fcs_output_txd_1 = {{7{XGMII_IDLE}}, XGMII_TERM};
fcs_output_txc_0 = 8'b00000000;
fcs_output_txc_1 = 8'b11111111;
ifg_offset = 8'd8;
extra_cycle = 1'b1;
end
8'bzz011111: begin
fcs_output_txd_0 = {~crc_next4[23:0], s_tdata_reg[39:0]};
fcs_output_txd_1 = {{6{XGMII_IDLE}}, XGMII_TERM, ~crc_next4[31:24]};
fcs_output_txc_0 = 8'b00000000;
fcs_output_txc_1 = 8'b11111110;
ifg_offset = 8'd7;
extra_cycle = 1'b1;
end
8'bz0111111: begin
fcs_output_txd_0 = {~crc_next5[15:0], s_tdata_reg[47:0]};
fcs_output_txd_1 = {{5{XGMII_IDLE}}, XGMII_TERM, ~crc_next5[31:16]};
fcs_output_txc_0 = 8'b00000000;
fcs_output_txc_1 = 8'b11111100;
ifg_offset = 8'd6;
extra_cycle = 1'b1;
end
8'b01111111: begin
fcs_output_txd_0 = {~crc_next6[7:0], s_tdata_reg[55:0]};
fcs_output_txd_1 = {{4{XGMII_IDLE}}, XGMII_TERM, ~crc_next6[31:8]};
fcs_output_txc_0 = 8'b00000000;
fcs_output_txc_1 = 8'b11111000;
ifg_offset = 8'd5;
extra_cycle = 1'b1;
end
8'b11111111: begin
fcs_output_txd_0 = s_tdata_reg;
fcs_output_txd_1 = {{3{XGMII_IDLE}}, XGMII_TERM, ~crc_next7[31:0]};
fcs_output_txc_0 = 8'b00000000;
fcs_output_txc_1 = 8'b11110000;
ifg_offset = 8'd4;
extra_cycle = 1'b1;
end
default: begin
fcs_output_txd_0 = {8{XGMII_ERROR}};
fcs_output_txd_1 = {8{XGMII_ERROR}};
fcs_output_txc_0 = 8'b11111111;
fcs_output_txc_1 = 8'b11111111;
ifg_offset = 8'd0;
extra_cycle = 1'b1;
end
endcase
end
always @* begin
state_next = STATE_IDLE;
reset_crc = 1'b0;
update_crc = 1'b0;
swap_lanes = 1'b0;
unswap_lanes = 1'b0;
frame_ptr_next = frame_ptr_reg;
ifg_count_next = ifg_count_reg;
deficit_idle_count_next = deficit_idle_count_reg;
s_axis_tready_next = 1'b0;
s_tdata_next = s_tdata_reg;
s_tkeep_next = s_tkeep_reg;
// XGMII idle
xgmii_txd_next = {8{XGMII_IDLE}};
xgmii_txc_next = 8'b11111111;
case (state_reg)
STATE_IDLE: begin
// idle state - wait for data
frame_ptr_next = 16'd8;
reset_crc = 1'b1;
s_axis_tready_next = 1'b1;
// XGMII idle
xgmii_txd_next = {8{XGMII_IDLE}};
xgmii_txc_next = 8'b11111111;
s_tdata_next = s_axis_tdata_masked;
s_tkeep_next = s_axis_tkeep;
if (s_axis_tvalid) begin
// XGMII start and preamble
if (ifg_count_reg > 8'd0) begin
// need to send more idles - swap lanes
swap_lanes = 1'b1;
end else begin
// no more idles - unswap
unswap_lanes = 1'b1;
end
xgmii_txd_next = {ETH_SFD, {6{ETH_PRE}}, XGMII_START};
xgmii_txc_next = 8'b00000001;
s_axis_tready_next = 1'b1;
state_next = STATE_PAYLOAD;
end else begin
ifg_count_next = 8'd0;
deficit_idle_count_next = 2'd0;
unswap_lanes = 1'b1;
state_next = STATE_IDLE;
end
end
STATE_PAYLOAD: begin
// transfer payload
update_crc = 1'b1;
s_axis_tready_next = 1'b1;
frame_ptr_next = frame_ptr_reg + 16'd8;
xgmii_txd_next = s_tdata_reg;
xgmii_txc_next = 8'b00000000;
s_tdata_next = s_axis_tdata_masked;
s_tkeep_next = s_axis_tkeep;
if (s_axis_tvalid) begin
if (s_axis_tlast) begin
frame_ptr_next = frame_ptr_reg + keep2count(s_axis_tkeep);
s_axis_tready_next = 1'b0;
if (s_axis_tuser) begin
xgmii_txd_next = {{3{XGMII_IDLE}}, XGMII_TERM, {4{XGMII_ERROR}}};
xgmii_txc_next = 8'b11111111;
frame_ptr_next = 16'd0;
ifg_count_next = 8'd8;
state_next = STATE_IFG;
end else begin
s_axis_tready_next = 1'b0;
if (ENABLE_PADDING && (frame_ptr_reg < MIN_FL_NOCRC_MS || (frame_ptr_reg == MIN_FL_NOCRC_MS && keep2count(s_axis_tkeep) < MIN_FL_NOCRC_LS))) begin
s_tkeep_next = 8'hff;
frame_ptr_next = frame_ptr_reg + 16'd8;
if (frame_ptr_reg < (MIN_FL_NOCRC_LS > 0 ? MIN_FL_NOCRC_MS : MIN_FL_NOCRC_MS-8)) begin
state_next = STATE_PAD;
end else begin
s_tkeep_next = 8'hff >> ((8-MIN_FL_NOCRC_LS) % 8);
state_next = STATE_FCS_1;
end
end else begin
state_next = STATE_FCS_1;
end
end
end else begin
state_next = STATE_PAYLOAD;
end
end else begin
// tvalid deassert, fail frame
xgmii_txd_next = {{3{XGMII_IDLE}}, XGMII_TERM, {4{XGMII_ERROR}}};
xgmii_txc_next = 8'b11111111;
frame_ptr_next = 16'd0;
ifg_count_next = 8'd8;
state_next = STATE_WAIT_END;
end
end
STATE_PAD: begin
// pad frame to MIN_FRAME_LENGTH
s_axis_tready_next = 1'b0;
xgmii_txd_next = s_tdata_reg;
xgmii_txc_next = 8'b00000000;
s_tdata_next = 64'd0;
s_tkeep_next = 8'hff;
update_crc = 1'b1;
frame_ptr_next = frame_ptr_reg + 16'd8;
if (frame_ptr_reg < (MIN_FL_NOCRC_LS > 0 ? MIN_FL_NOCRC_MS : MIN_FL_NOCRC_MS-8)) begin
state_next = STATE_PAD;
end else begin
s_tkeep_next = 8'hff >> ((8-MIN_FL_NOCRC_LS) % 8);
state_next = STATE_FCS_1;
end
end
STATE_FCS_1: begin
// last cycle
s_axis_tready_next = 1'b0;
xgmii_txd_next = fcs_output_txd_0;
xgmii_txc_next = fcs_output_txc_0;
frame_ptr_next = 16'd0;
ifg_count_next = (ifg_delay > 8'd12 ? ifg_delay : 8'd12) - ifg_offset + (lanes_swapped ? 8'd4 : 8'd0) + deficit_idle_count_reg;
if (extra_cycle) begin
state_next = STATE_FCS_2;
end else begin
state_next = STATE_IFG;
end
end
STATE_FCS_2: begin
// last cycle
s_axis_tready_next = 1'b0;
xgmii_txd_next = fcs_output_txd_1;
xgmii_txc_next = fcs_output_txc_1;
reset_crc = 1'b1;
frame_ptr_next = 16'd0;
if (ENABLE_DIC) begin
if (ifg_count_next > 8'd7) begin
state_next = STATE_IFG;
end else begin
if (ifg_count_next >= 8'd4) begin
deficit_idle_count_next = ifg_count_next - 8'd4;
end else begin
deficit_idle_count_next = ifg_count_next;
ifg_count_next = 8'd0;
end
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end else begin
if (ifg_count_next > 8'd4) begin
state_next = STATE_IFG;
end else begin
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end
end
STATE_IFG: begin
// send IFG
if (ifg_count_reg > 8'd8) begin
ifg_count_next = ifg_count_reg - 8'd8;
end else begin
ifg_count_next = 8'd0;
end
reset_crc = 1'b1;
if (ENABLE_DIC) begin
if (ifg_count_next > 8'd7) begin
state_next = STATE_IFG;
end else begin
if (ifg_count_next >= 8'd4) begin
deficit_idle_count_next = ifg_count_next - 8'd4;
end else begin
deficit_idle_count_next = ifg_count_next;
ifg_count_next = 8'd0;
end
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end else begin
if (ifg_count_next > 8'd4) begin
state_next = STATE_IFG;
end else begin
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end
end
STATE_WAIT_END: begin
// wait for end of frame
if (ifg_count_reg > 8'd8) begin
ifg_count_next = ifg_count_reg - 8'd8;
end else begin
ifg_count_next = 8'd0;
end
reset_crc = 1'b1;
if (s_axis_tvalid) begin
if (s_axis_tlast) begin
if (ENABLE_DIC) begin
if (ifg_count_next > 8'd7) begin
state_next = STATE_IFG;
end else begin
if (ifg_count_next >= 8'd4) begin
deficit_idle_count_next = ifg_count_next - 8'd4;
end else begin
deficit_idle_count_next = ifg_count_next;
ifg_count_next = 8'd0;
end
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end else begin
if (ifg_count_next > 8'd4) begin
state_next = STATE_IFG;
end else begin
s_axis_tready_next = 1'b1;
state_next = STATE_IDLE;
end
end
end else begin
state_next = STATE_WAIT_END;
end
end else begin
state_next = STATE_WAIT_END;
end
end
endcase
end
always @(posedge clk) begin
if (rst) begin
state_reg <= STATE_IDLE;
frame_ptr_reg <= 16'd0;
ifg_count_reg <= 8'd0;
deficit_idle_count_reg <= 2'd0;
s_axis_tready_reg <= 1'b0;
xgmii_txd_reg <= {8{XGMII_IDLE}};
xgmii_txc_reg <= 8'b11111111;
crc_state <= 32'hFFFFFFFF;
lanes_swapped <= 1'b0;
end else begin
state_reg <= state_next;
frame_ptr_reg <= frame_ptr_next;
ifg_count_reg <= ifg_count_next;
deficit_idle_count_reg <= deficit_idle_count_next;
s_axis_tready_reg <= s_axis_tready_next;
if (swap_lanes || (lanes_swapped && !unswap_lanes)) begin
lanes_swapped <= 1'b1;
xgmii_txd_reg <= {xgmii_txd_next[31:0], swap_txd};
xgmii_txc_reg <= {xgmii_txc_next[3:0], swap_txc};
end else begin
lanes_swapped <= 1'b0;
xgmii_txd_reg <= xgmii_txd_next;
xgmii_txc_reg <= xgmii_txc_next;
end
// datapath
if (reset_crc) begin
crc_state <= 32'hFFFFFFFF;
end else if (update_crc) begin
crc_state <= crc_next7;
end
end
s_tdata_reg <= s_tdata_next;
s_tkeep_reg <= s_tkeep_next;
swap_txd <= xgmii_txd_next[63:32];
swap_txc <= xgmii_txc_next[7:4];
end
endmodule
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