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Add simple UDP Ethernet packet generator

This commit is contained in:
Konstantin Pavlov 2023-05-23 13:07:08 +03:00
parent bb0897a409
commit 213e17c657
2 changed files with 385 additions and 0 deletions

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//------------------------------------------------------------------------------
// udp_packet.sv
// published as part of https://github.com/pConst/basic_verilog
// Konstantin Pavlov, pavlovconst@gmail.com
//------------------------------------------------------------------------------
// INFO ------------------------------------------------------------------------
// A simple hardcoded UDP packet generator
//
/* --- INSTANTIATION TEMPLATE BEGIN ---
udp_packet #(
.MODE( "BYTES" ) // "BYTES" or "NIBBLES"
) UP1 (
.clk( clk ),
.nrst( nrst ),
.tx_en( ),
.od( )
);
--- INSTANTIATION TEMPLATE END ---*/
module udp_packet #( parameter
MODE = "BYTES" // "BYTES" or "NIBBLES"
)(
input clk,
input nrst,
output logic tx_en = 1'b0,
output logic [7:0] od = '0
);
logic [15:0] seq_cntr = '0;
logic nibble_high = 1'b0;
logic [7:0] data_byte;
// tx_en and od signals are late one cycle after their respective seq_cntr[]
always_ff @(posedge clk) begin
if( ~nrst ) begin
tx_en = 1'b0;
od[7:0] = '0;
seq_cntr[15:0] <= '0;
nibble_high <= 1'b0;
end else begin
if ( MODE == "BYTES" ) begin
tx_en <= ( (seq_cntr[15:0] >=0) &&
(seq_cntr[15:0] <72) );
od[7:0] <= data_byte[7:0];
if (seq_cntr[15:0] == 255 ) begin
// sequence reset
seq_cntr[15:0] <= '0;
end else begin
seq_cntr[15:0] <= seq_cntr[15:0] + 1'b1;
end
end else begin
tx_en <= ( (seq_cntr[15:0] >=0) &&
(seq_cntr[15:0] <72) );
if( nibble_high ) begin
od[7:0] <= {4'h0,data_byte[3:0]};
if (seq_cntr[15:0] == 127 ) begin
// sequence reset
seq_cntr[15:0] <= '0;
end else begin
seq_cntr[15:0] <= seq_cntr[15:0] + 1'b1;
end
end else begin
od[7:0] <= {4'h0,data_byte[7:4]};
end // if
nibble_high <= !nibble_high;
end // if
end
end
always_comb begin
case ( seq_cntr[15:0] )
// Sending the preambule and asserting tx_en
0 : data_byte[7:0] <= 8'h55;
1 : data_byte[7:0] <= 8'h55;
2 : data_byte[7:0] <= 8'h55;
3 : data_byte[7:0] <= 8'h55;
4 : data_byte[7:0] <= 8'h55;
5 : data_byte[7:0] <= 8'h55;
6 : data_byte[7:0] <= 8'h55;
7 : data_byte[7:0] <= 8'hd5;
// Sending the UDP/IP-packet itself
8 : data_byte[7:0] <= 8'hd8;
9 : data_byte[7:0] <= 8'hd3;
10: data_byte[7:0] <= 8'h85;
11: data_byte[7:0] <= 8'h26;
12: data_byte[7:0] <= 8'hc5;
13: data_byte[7:0] <= 8'h78;
14: data_byte[7:0] <= 8'h00;
15: data_byte[7:0] <= 8'h23;
16: data_byte[7:0] <= 8'h54;
17: data_byte[7:0] <= 8'h3c;
18: data_byte[7:0] <= 8'h47;
19: data_byte[7:0] <= 8'h1b;
20: data_byte[7:0] <= 8'h08;
21: data_byte[7:0] <= 8'h00;
22: data_byte[7:0] <= 8'h45;
23: data_byte[7:0] <= 8'h00;
24: data_byte[7:0] <= 8'h00;
25: data_byte[7:0] <= 8'h2e;
26: data_byte[7:0] <= 8'h00;
27: data_byte[7:0] <= 8'h00;
28: data_byte[7:0] <= 8'h00;
29: data_byte[7:0] <= 8'h00;
30: data_byte[7:0] <= 8'hc8;
31: data_byte[7:0] <= 8'h11;
32: data_byte[7:0] <= 8'hd6;
33: data_byte[7:0] <= 8'h73;
34: data_byte[7:0] <= 8'hc0;
35: data_byte[7:0] <= 8'ha8;
36: data_byte[7:0] <= 8'h4d;
37: data_byte[7:0] <= 8'h21;
38: data_byte[7:0] <= 8'hc0;
39: data_byte[7:0] <= 8'ha8;
40: data_byte[7:0] <= 8'h4d;
41: data_byte[7:0] <= 8'hd9;
42: data_byte[7:0] <= 8'hc3;
43: data_byte[7:0] <= 8'h50;
44: data_byte[7:0] <= 8'hc3;
45: data_byte[7:0] <= 8'h60;
46: data_byte[7:0] <= 8'h00;
47: data_byte[7:0] <= 8'h1a;
48: data_byte[7:0] <= 8'h00;
49: data_byte[7:0] <= 8'h00;
50: data_byte[7:0] <= 8'h01;
51: data_byte[7:0] <= 8'h02;
52: data_byte[7:0] <= 8'h03;
53: data_byte[7:0] <= 8'h04;
54: data_byte[7:0] <= 8'h01;
55: data_byte[7:0] <= 8'h01;
56: data_byte[7:0] <= 8'h01;
57: data_byte[7:0] <= 8'h01;
58: data_byte[7:0] <= 8'h01;
59: data_byte[7:0] <= 8'h01;
60: data_byte[7:0] <= 8'h01;
61: data_byte[7:0] <= 8'h01;
62: data_byte[7:0] <= 8'h01;
63: data_byte[7:0] <= 8'h01;
64: data_byte[7:0] <= 8'h01;
65: data_byte[7:0] <= 8'h01;
66: data_byte[7:0] <= 8'h01;
67: data_byte[7:0] <= 8'h01;
// CRC32 checksum
68: data_byte[7:0] <= 8'he3;
69: data_byte[7:0] <= 8'h8e;
70: data_byte[7:0] <= 8'hdf;
71: data_byte[7:0] <= 8'h1f;
default: data_byte[7:0] <= '0; // pause
endcase
end
endmodule

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//------------------------------------------------------------------------------
// udp_packet_tb.sv
// published as part of https://github.com/pConst/basic_verilog
// Konstantin Pavlov, pavlovconst@gmail.com
//------------------------------------------------------------------------------
// INFO ------------------------------------------------------------------------
// udp_packet testbench
// use this define to make some things differently in simulation
`define SIMULATION yes
`timescale 1ns / 1ps
module udp_packet_tb();
initial begin
// Print out time markers in nanoseconds
// Example: $display("[T=%0t] start=%d", $realtime, start);
$timeformat(-9, 3, " ns");
// seed value setting is intentionally manual to achieve repeatability between sim runs
$urandom( 1 ); // SEED value
end
logic clk200;
sim_clk_gen #(
.FREQ( 200_000_000 ), // in Hz
.PHASE( 0 ), // in degrees
.DUTY( 50 ), // in percentage
.DISTORT( 10 ) // in picoseconds
) clk200_gen (
.ena( 1'b1 ),
.clk( clk200 ),
.clkd( )
);
logic nrst_once;
logic [31:0] clk200_div;
clk_divider #(
.WIDTH( 32 )
) cd1 (
.clk( clk200 ),
.nrst( nrst_once ),
.ena( 1'b1 ),
.out( clk200_div[31:0] )
);
logic [31:0] clk200_div_rise;
edge_detect ed1[31:0] (
.clk( {32{clk200}} ),
.anrst( {32{nrst_once}} ),
.in( clk200_div[31:0] ),
.rising( clk200_div_rise[31:0] ),
.falling( ),
.both( )
);
// external device "asynchronous" clock
logic clk33;
logic clk33d;
sim_clk_gen #(
.FREQ( 200_000_000 ), // in Hz
.PHASE( 0 ), // in degrees
.DUTY( 50 ), // in percentage
.DISTORT( 1000 ) // in picoseconds
) clk33_gen (
.ena( 1'b1 ),
.clk( clk33 ),
.clkd( clk33d )
);
logic rst;
initial begin
rst = 1'b0; // initialization
repeat( 1 ) @(posedge clk200);
forever begin
repeat( 1 ) @(posedge clk200); // synchronous rise
rst = 1'b1;
//$urandom( 1 ); // uncomment to get the same random pattern EVERY nrst
repeat( 2 ) @(posedge clk200); // synchronous fall, controls rst pulse width
rst = 1'b0;
repeat( 100 ) @(posedge clk200); // controls test body width
end
end
logic nrst;
assign nrst = ~rst;
logic rst_once;
initial begin
rst_once = 1'b0; // initialization
repeat( 1 ) @(posedge clk200);
repeat( 1 ) @(posedge clk200); // synchronous rise
rst_once = 1'b1;
repeat( 2 ) @(posedge clk200); // synchronous fall, controls rst_once pulse width
rst_once = 1'b0;
end
//logic nrst_once; // declared before
assign nrst_once = ~rst_once;
// random pattern generation
logic [31:0] rnd_data;
always_ff @(posedge clk200) begin
rnd_data[31:0] <= $urandom;
end
initial forever begin
@(posedge nrst);
$display("[T=%0t] rnd_data[]=%h", $realtime, rnd_data[31:0]);
end
// helper start strobe appears unpredictable up to 20 clocks after nrst
logic start;
initial forever begin
start = 1'b0; // initialization
@(posedge nrst); // synchronous rise after EVERY nrst
repeat( $urandom_range(0, 20) ) @(posedge clk200);
start = 1'b1;
@(posedge clk200); // synchronous fall exactly 1 clock after rise
start = 1'b0;
end
initial begin
// #10000 $stop;
// #10000 $finish;
end
// sweeping pulses
logic sp = 1'b1;
logic [4:0] sp_duty_cycle = 8'd0;
initial forever begin
if( sp_duty_cycle[4:0] == 0 ) begin
sp = 1'b1;
repeat( 10 ) @(posedge clk200);
end
sp = 1'b0;
repeat( 1 ) @(posedge clk200);
sp = 1'b1;
repeat( 1 ) @(posedge clk200);
sp = 1'b0;
repeat( sp_duty_cycle ) @(posedge clk200);
sp_duty_cycle[4:0] = sp_duty_cycle[4:0] + 1'b1; // overflow is expected here
end
// Module under test ===========================================================
logic [15:0] seq_cntr = '0;
logic [31:0] id = '0;
always_ff @(posedge clk200) begin
if( ~nrst_once ) begin
seq_cntr[15:0] <= '0;
id[31:0] <= '0;
end else begin
// incrementing sequence counter
if( seq_cntr[15:0]!= '1 ) begin
seq_cntr[15:0] <= seq_cntr[15:0] + 1'b1;
end
if( seq_cntr[15:0]<300 ) begin
id[31:0] <= '1;
//id[31:0] <= {4{rnd_data[15:0]}};
end else begin
id[31:0] <= '0;
end
end
end
udp_packet #(
.MODE( "BYTES" ) // "BYTES" or "NIBBLES"
) M1 (
.clk( clk200 ),
.nrst( nrst_once ),
.tx_en( ),
.od( )
);
udp_packet #(
.MODE( "NIBBLES" ) // "BYTES" or "NIBBLES"
) M2 (
.clk( clk200 ),
.nrst( nrst_once ),
.tx_en( ),
.od( )
);
endmodule