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verilog-ethernet/rtl/eth_axis_rx_64.v
Alex Forencich fb4abb6b39 Fix widths
2019-03-14 14:44:00 -07:00

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Verilog
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/*
Copyright (c) 2014-2018 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 ethernet frame receiver (AXI in, Ethernet frame out, 64 bit datapath)
*/
module eth_axis_rx_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,
/*
* Ethernet frame output
*/
output wire m_eth_hdr_valid,
input wire m_eth_hdr_ready,
output wire [47:0] m_eth_dest_mac,
output wire [47:0] m_eth_src_mac,
output wire [15:0] m_eth_type,
output wire [63:0] m_eth_payload_axis_tdata,
output wire [7:0] m_eth_payload_axis_tkeep,
output wire m_eth_payload_axis_tvalid,
input wire m_eth_payload_axis_tready,
output wire m_eth_payload_axis_tlast,
output wire m_eth_payload_axis_tuser,
/*
* Status signals
*/
output wire busy,
output wire error_header_early_termination
);
/*
Ethernet frame
Field Length
Destination MAC address 6 octets
Source MAC address 6 octets
Ethertype 2 octets
This module receives an Ethernet frame on an AXI stream interface, decodes
and strips the headers, then produces the header fields in parallel along
with the payload in a separate AXI stream.
*/
localparam [2:0]
STATE_IDLE = 3'd0,
STATE_READ_HEADER = 3'd1,
STATE_READ_PAYLOAD = 3'd2;
reg [2:0] state_reg = STATE_IDLE, state_next;
// datapath control signals
reg store_hdr_word_0;
reg store_hdr_word_1;
reg flush_save;
reg transfer_in_save;
reg [7:0] frame_ptr_reg = 8'd0, frame_ptr_next;
reg s_axis_tready_reg = 1'b0, s_axis_tready_next;
reg m_eth_hdr_valid_reg = 1'b0, m_eth_hdr_valid_next;
reg [47:0] m_eth_dest_mac_reg = 48'd0;
reg [47:0] m_eth_src_mac_reg = 48'd0;
reg [15:0] m_eth_type_reg = 16'd0;
reg busy_reg = 1'b0;
reg error_header_early_termination_reg = 1'b0, error_header_early_termination_next;
reg [63:0] save_axis_tdata_reg = 64'd0;
reg [7:0] save_axis_tkeep_reg = 8'd0;
reg save_axis_tlast_reg = 1'b0;
reg save_axis_tuser_reg = 1'b0;
reg [63:0] shift_axis_tdata;
reg [7:0] shift_axis_tkeep;
reg shift_axis_tvalid;
reg shift_axis_tlast;
reg shift_axis_tuser;
reg shift_axis_s_tready;
reg shift_axis_extra_cycle;
// internal datapath
reg [63:0] m_eth_payload_axis_tdata_int;
reg [7:0] m_eth_payload_axis_tkeep_int;
reg m_eth_payload_axis_tvalid_int;
reg m_eth_payload_axis_tready_int_reg = 1'b0;
reg m_eth_payload_axis_tlast_int;
reg m_eth_payload_axis_tuser_int;
wire m_eth_payload_axis_tready_int_early;
assign s_axis_tready = s_axis_tready_reg;
assign m_eth_hdr_valid = m_eth_hdr_valid_reg;
assign m_eth_dest_mac = m_eth_dest_mac_reg;
assign m_eth_src_mac = m_eth_src_mac_reg;
assign m_eth_type = m_eth_type_reg;
assign busy = busy_reg;
assign error_header_early_termination = error_header_early_termination_reg;
always @* begin
shift_axis_tdata[15:0] = save_axis_tdata_reg[63:48];
shift_axis_tkeep[1:0] = save_axis_tkeep_reg[7:6];
shift_axis_extra_cycle = save_axis_tlast_reg && (save_axis_tkeep_reg[7:6] != 0);
if (shift_axis_extra_cycle) begin
shift_axis_tdata[63:16] = 48'd0;
shift_axis_tkeep[7:2] = 6'd0;
shift_axis_tvalid = 1'b1;
shift_axis_tlast = save_axis_tlast_reg;
shift_axis_tuser = save_axis_tuser_reg;
shift_axis_s_tready = flush_save;
end else begin
shift_axis_tdata[63:16] = s_axis_tdata[47:0];
shift_axis_tkeep[7:2] = s_axis_tkeep[5:0];
shift_axis_tvalid = s_axis_tvalid;
shift_axis_tlast = (s_axis_tlast && (s_axis_tkeep[7:6] == 0));
shift_axis_tuser = (s_axis_tuser && (s_axis_tkeep[7:6] == 0));
shift_axis_s_tready = !(s_axis_tlast && s_axis_tvalid && transfer_in_save);
end
end
always @* begin
state_next = STATE_IDLE;
s_axis_tready_next = 1'b0;
flush_save = 1'b0;
transfer_in_save = 1'b0;
store_hdr_word_0 = 1'b0;
store_hdr_word_1 = 1'b0;
frame_ptr_next = frame_ptr_reg;
m_eth_hdr_valid_next = m_eth_hdr_valid_reg && !m_eth_hdr_ready;
error_header_early_termination_next = 1'b0;
m_eth_payload_axis_tdata_int = 64'd0;
m_eth_payload_axis_tkeep_int = 8'd0;
m_eth_payload_axis_tvalid_int = 1'b0;
m_eth_payload_axis_tlast_int = 1'b0;
m_eth_payload_axis_tuser_int = 1'b0;
case (state_reg)
STATE_IDLE: begin
// idle state - wait for data
frame_ptr_next = 8'd0;
flush_save = 1'b1;
s_axis_tready_next = !m_eth_hdr_valid_reg;
if (s_axis_tready && s_axis_tvalid) begin
// got first word of packet
if (s_axis_tlast) begin
// tlast asserted on first word
error_header_early_termination_next = 1'b1;
state_next = STATE_IDLE;
end else begin
// move to read header state
frame_ptr_next = 8'd8;
store_hdr_word_0 = 1'b1;
transfer_in_save = 1'b1;
state_next = STATE_READ_HEADER;
end
end else begin
state_next = STATE_IDLE;
end
end
STATE_READ_HEADER: begin
// read header state
s_axis_tready_next = 1'b1;
if (s_axis_tready && s_axis_tvalid) begin
// word transfer in - store it
frame_ptr_next = frame_ptr_reg + 8'd8;
transfer_in_save = 1'b1;
state_next = STATE_READ_HEADER;
case (frame_ptr_reg)
8'h00: store_hdr_word_0 = 1'b1;
8'h08: begin
store_hdr_word_1 = 1'b1;
m_eth_hdr_valid_next = 1'b1;
s_axis_tready_next = m_eth_payload_axis_tready_int_early;
state_next = STATE_READ_PAYLOAD;
end
endcase
if (s_axis_tlast) begin
if (s_axis_tkeep[7:6] != 2'd0) begin
s_axis_tready_next = 1'b0;
state_next = STATE_READ_PAYLOAD;
end else begin
flush_save = 1'b1;
m_eth_hdr_valid_next = 1'b0;
error_header_early_termination_next = 1'b1;
s_axis_tready_next = !m_eth_hdr_valid_reg;
state_next = STATE_IDLE;
end
end
end else begin
state_next = STATE_READ_HEADER;
end
end
STATE_READ_PAYLOAD: begin
// read payload
s_axis_tready_next = m_eth_payload_axis_tready_int_early && shift_axis_s_tready;
m_eth_payload_axis_tdata_int = shift_axis_tdata;
m_eth_payload_axis_tkeep_int = shift_axis_tkeep;
m_eth_payload_axis_tvalid_int = shift_axis_tvalid;
m_eth_payload_axis_tlast_int = shift_axis_tlast;
m_eth_payload_axis_tuser_int = shift_axis_tuser;
if (m_eth_payload_axis_tready_int_reg && shift_axis_tvalid) begin
// word transfer through
transfer_in_save = 1'b1;
if (shift_axis_tlast) begin
flush_save = 1'b1;
s_axis_tready_next = !m_eth_hdr_valid_reg;
state_next = STATE_IDLE;
end else begin
state_next = STATE_READ_PAYLOAD;
end
end else begin
state_next = STATE_READ_PAYLOAD;
end
end
endcase
end
always @(posedge clk) begin
if (rst) begin
state_reg <= STATE_IDLE;
frame_ptr_reg <= 8'd0;
s_axis_tready_reg <= 1'b0;
m_eth_hdr_valid_reg <= 1'b0;
save_axis_tlast_reg <= 1'b0;
busy_reg <= 1'b0;
error_header_early_termination_reg <= 1'b0;
end else begin
state_reg <= state_next;
frame_ptr_reg <= frame_ptr_next;
s_axis_tready_reg <= s_axis_tready_next;
m_eth_hdr_valid_reg <= m_eth_hdr_valid_next;
error_header_early_termination_reg <= error_header_early_termination_next;
busy_reg <= state_next != STATE_IDLE;
if (flush_save) begin
save_axis_tlast_reg <= 1'b0;
end else if (transfer_in_save) begin
save_axis_tlast_reg <= s_axis_tlast;
end
end
// datapath
if (store_hdr_word_0) begin
m_eth_dest_mac_reg[47:40] <= s_axis_tdata[ 7: 0];
m_eth_dest_mac_reg[39:32] <= s_axis_tdata[15: 8];
m_eth_dest_mac_reg[31:24] <= s_axis_tdata[23:16];
m_eth_dest_mac_reg[23:16] <= s_axis_tdata[31:24];
m_eth_dest_mac_reg[15: 8] <= s_axis_tdata[39:32];
m_eth_dest_mac_reg[ 7: 0] <= s_axis_tdata[47:40];
m_eth_src_mac_reg[47:40] <= s_axis_tdata[55:48];
m_eth_src_mac_reg[39:32] <= s_axis_tdata[63:56];
end
if (store_hdr_word_1) begin
m_eth_src_mac_reg[31:24] <= s_axis_tdata[ 7: 0];
m_eth_src_mac_reg[23:16] <= s_axis_tdata[15: 8];
m_eth_src_mac_reg[15: 8] <= s_axis_tdata[23:16];
m_eth_src_mac_reg[ 7: 0] <= s_axis_tdata[31:24];
m_eth_type_reg[15:8] <= s_axis_tdata[39:32];
m_eth_type_reg[ 7:0] <= s_axis_tdata[47:40];
end
if (transfer_in_save) begin
save_axis_tdata_reg <= s_axis_tdata;
save_axis_tkeep_reg <= s_axis_tkeep;
save_axis_tuser_reg <= s_axis_tuser;
end
end
// output datapath logic
reg [63:0] m_eth_payload_axis_tdata_reg = 64'd0;
reg [7:0] m_eth_payload_axis_tkeep_reg = 8'd0;
reg m_eth_payload_axis_tvalid_reg = 1'b0, m_eth_payload_axis_tvalid_next;
reg m_eth_payload_axis_tlast_reg = 1'b0;
reg m_eth_payload_axis_tuser_reg = 1'b0;
reg [63:0] temp_m_eth_payload_axis_tdata_reg = 64'd0;
reg [7:0] temp_m_eth_payload_axis_tkeep_reg = 8'd0;
reg temp_m_eth_payload_axis_tvalid_reg = 1'b0, temp_m_eth_payload_axis_tvalid_next;
reg temp_m_eth_payload_axis_tlast_reg = 1'b0;
reg temp_m_eth_payload_axis_tuser_reg = 1'b0;
// datapath control
reg store_eth_payload_int_to_output;
reg store_eth_payload_int_to_temp;
reg store_eth_payload_axis_temp_to_output;
assign m_eth_payload_axis_tdata = m_eth_payload_axis_tdata_reg;
assign m_eth_payload_axis_tkeep = m_eth_payload_axis_tkeep_reg;
assign m_eth_payload_axis_tvalid = m_eth_payload_axis_tvalid_reg;
assign m_eth_payload_axis_tlast = m_eth_payload_axis_tlast_reg;
assign m_eth_payload_axis_tuser = m_eth_payload_axis_tuser_reg;
// enable ready input next cycle if output is ready or the temp reg will not be filled on the next cycle (output reg empty or no input)
assign m_eth_payload_axis_tready_int_early = m_eth_payload_axis_tready || (!temp_m_eth_payload_axis_tvalid_reg && (!m_eth_payload_axis_tvalid_reg || !m_eth_payload_axis_tvalid_int));
always @* begin
// transfer sink ready state to source
m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_reg;
temp_m_eth_payload_axis_tvalid_next = temp_m_eth_payload_axis_tvalid_reg;
store_eth_payload_int_to_output = 1'b0;
store_eth_payload_int_to_temp = 1'b0;
store_eth_payload_axis_temp_to_output = 1'b0;
if (m_eth_payload_axis_tready_int_reg) begin
// input is ready
if (m_eth_payload_axis_tready || !m_eth_payload_axis_tvalid_reg) begin
// output is ready or currently not valid, transfer data to output
m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_int;
store_eth_payload_int_to_output = 1'b1;
end else begin
// output is not ready, store input in temp
temp_m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_int;
store_eth_payload_int_to_temp = 1'b1;
end
end else if (m_eth_payload_axis_tready) begin
// input is not ready, but output is ready
m_eth_payload_axis_tvalid_next = temp_m_eth_payload_axis_tvalid_reg;
temp_m_eth_payload_axis_tvalid_next = 1'b0;
store_eth_payload_axis_temp_to_output = 1'b1;
end
end
always @(posedge clk) begin
if (rst) begin
m_eth_payload_axis_tvalid_reg <= 1'b0;
m_eth_payload_axis_tready_int_reg <= 1'b0;
temp_m_eth_payload_axis_tvalid_reg <= 1'b0;
end else begin
m_eth_payload_axis_tvalid_reg <= m_eth_payload_axis_tvalid_next;
m_eth_payload_axis_tready_int_reg <= m_eth_payload_axis_tready_int_early;
temp_m_eth_payload_axis_tvalid_reg <= temp_m_eth_payload_axis_tvalid_next;
end
// datapath
if (store_eth_payload_int_to_output) begin
m_eth_payload_axis_tdata_reg <= m_eth_payload_axis_tdata_int;
m_eth_payload_axis_tkeep_reg <= m_eth_payload_axis_tkeep_int;
m_eth_payload_axis_tlast_reg <= m_eth_payload_axis_tlast_int;
m_eth_payload_axis_tuser_reg <= m_eth_payload_axis_tuser_int;
end else if (store_eth_payload_axis_temp_to_output) begin
m_eth_payload_axis_tdata_reg <= temp_m_eth_payload_axis_tdata_reg;
m_eth_payload_axis_tkeep_reg <= temp_m_eth_payload_axis_tkeep_reg;
m_eth_payload_axis_tlast_reg <= temp_m_eth_payload_axis_tlast_reg;
m_eth_payload_axis_tuser_reg <= temp_m_eth_payload_axis_tuser_reg;
end
if (store_eth_payload_int_to_temp) begin
temp_m_eth_payload_axis_tdata_reg <= m_eth_payload_axis_tdata_int;
temp_m_eth_payload_axis_tkeep_reg <= m_eth_payload_axis_tkeep_int;
temp_m_eth_payload_axis_tlast_reg <= m_eth_payload_axis_tlast_int;
temp_m_eth_payload_axis_tuser_reg <= m_eth_payload_axis_tuser_int;
end
end
endmodule
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