playground/par_to_ser_tb.v


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`timescale 1us/1us

module par_to_ser_tb;

logic clk_i;
logic rst_i;
logic data_valid_i;
logic [7:0] dat_i;
logic dat_o;

par_to_ser uut (
  .clk_i(clk_i),
  .rst_i(rst_i),
  .data_valid_i(data_valid_i),
  .dat_i(dat_i),
  .dat_o(dat_o),
  .dat_valid_o()
);

string filename;
initial begin
`ifdef DUMP_FILE_NAME
  filename=`DUMP_FILE_NAME;
`else
  filename="par_to_ser.lxt2";
`endif
  $dumpfile(filename); $dumpvars();
  clk_i = 0;
  rst_i = 1'b1;
  data_valid_i = 1'b0;

  #1
  rst_i = 1'b0;
  #1
  rst_i = 1'b1;
end

always #10 clk_i = ~clk_i;

bit sollbit = 1'b0;

initial begin
  #13
  @(negedge clk_i);

  for (integer i = 0; i < 255; i++) begin
    // clock data in
    dat_i = i;
    data_valid_i = 1'b1;

    @(negedge clk_i);
    data_valid_i = 1'b0;

    for (integer j = 0; j < 8; j++) begin
      sollbit = (i >> j) & 1;
      assert(dat_o == sollbit)
      else $error("Expected bit to be %d, but was %d", sollbit, dat_o);

      @(negedge clk_i);
    end

    repeat(2) @(negedge clk_i);
  end

  $finish();
end

endmodule