| `default_nettype none | 
 | `timescale 1ns / 1ps | 
 |  | 
 | `include "../src/message_formatter.v" | 
 |  | 
 | // ============================================================================ | 
 |  | 
 | module tb; | 
 |  | 
 | // ============================================================================ | 
 |  | 
 | reg CLK; | 
 | initial CLK <= 1'b0; | 
 | always #0.5 CLK <= !CLK; | 
 |  | 
 | reg [3:0] rst_sr; | 
 | initial rst_sr <= 4'hF; | 
 | always @(posedge CLK) rst_sr <= rst_sr >> 1; | 
 | wire RST; | 
 | assign RST = rst_sr[0]; | 
 |  | 
 | // ============================================================================ | 
 |  | 
 | initial begin | 
 |     $dumpfile("waveforms.vcd"); | 
 |     $dumpvars; | 
 | end | 
 |  | 
 | integer cycle_cnt; | 
 | initial cycle_cnt <= 0; | 
 |  | 
 | always @(posedge CLK) | 
 |     if (!RST) cycle_cnt <= cycle_cnt + 1; | 
 |  | 
 | always @(posedge CLK) | 
 |     if (!RST && cycle_cnt >= 150) | 
 |         $finish; | 
 |  | 
 | // ============================================================================ | 
 |  | 
 | wire i_stb = (cycle_cnt == 10); | 
 | wire [32*2-1:0] i_dat = 64'h01234567_ABCD4321; | 
 |  | 
 | wire o_stb; | 
 | wire [7:0] o_dat; | 
 |  | 
 | message_formatter # | 
 | ( | 
 | .WIDTH          (32), | 
 | .COUNT          (2), | 
 | .TX_INTERVAL    (4) | 
 | ) | 
 | dut | 
 | ( | 
 | .CLK    (CLK), | 
 | .RST    (RST), | 
 |  | 
 | .I_STB  (i_stb), | 
 | .I_DAT  (i_dat), | 
 |  | 
 | .O_STB  (o_stb), | 
 | .O_DAT  (o_dat) | 
 | ); | 
 |  | 
 | always @(posedge CLK) | 
 |     if (o_stb) | 
 |         $display("%c", o_dat); | 
 |  | 
 | endmodule | 
 |  |