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/*******************************************************************************

 *

 * Copyright 2012, Sinclair R.F., Inc.

 *

 * Test bench for hello_world.v.

 *

 ******************************************************************************/

`timescale 1ns/1ps

module tb;

// 100 MHz clock (as per hello_world.9x8/baudmethod)

reg s_clk = 1'b1;

always @ (s_clk) s_clk <= #5 ~s_clk;

reg s_rst = 1'b1;

initial begin

  repeat (5) @ (posedge s_clk);

  s_rst <= 1'b0;

  repeat((13+1)*10*((100_000_000+115200/2)/115200+12)) @ (posedge s_clk);

  $finish;

end

wire s_UART_Tx;

hello_world uut(

  // synchronous reset and processor clock

  .i_rst        (s_rst),

  .i_clk        (s_clk),

  // outport ports

  .o_UART_Tx    (s_UART_Tx)

);

localparam baud = 115200;

localparam dt_baud = 1.0e9/baud;

reg [8:0] deser = 9'h1FF;

initial forever begin

  @ (negedge s_UART_Tx);

  #(dt_baud/2.0);

  repeat (9) begin

    #dt_baud;

    deser = { s_UART_Tx, deser[1+:8] };

  end

  if (deser[8] != 1'b1)

    $display("%13d : Malformed UART transmition", $time);

  else if ((8'h20 <= deser[0+:8]) && (deser[0+:8]<=8'h80))

    $display("%13d : Sent 0x%02H : %c", $time, deser[0+:8], deser[0+:8]);

  else

    $display("%13d : Sent 0x%02H", $time, deser[0+:8]);

end

initial begin

  $dumpfile("tb.vcd");

  $dumpvars();

end

endmodule