playground/led_toggle_tb.v


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`timescale 1us/1us

module led_toggle_tb;

logic clk_i;
logic rst_i;
logic key_i;

logic [5:0] led;

led_toggle #(.STABLE_PERIOD(2)) uut (
  .rst_i(rst_i),
  .clk_i(clk_i),
  .key_i(key_i),
  .led(led)
);

string filename;
initial begin
`ifdef DUMP_FILE_NAME
  filename=`DUMP_FILE_NAME;
`else
  filename="led_toggle.lxt2";
`endif
  $dumpfile(filename); $dumpvars();
  clk_i = 0;
  key_i = 1'b1;
  #1
  rst_i = 0;
  #1
  rst_i = 1;
end

always #10 clk_i = ~clk_i;


initial begin
  // initial key press
  #13
  key_i = ~key_i;
  repeat(2) @(negedge clk_i);
  key_i = ~key_i;

  // try bouncing

  repeat(3) @(negedge clk_i);

  for (integer i=0; i < 19; i = i + 1) begin
    @(negedge clk_i);
    key_i = ~key_i;
  end
  repeat(10) @(negedge clk_i);
  key_i = ~key_i;

  repeat(10) @(negedge clk_i);
  $finish();
end

endmodule