| /* Binary counter displayed on LEDs (the 4 green ones on the right). |
| * Changes value about once a second. |
| */ |
| |
| `ifndef CLK_MHZ |
| `define CLK_MHZ 24 |
| `endif |
| |
| module top ( |
| input clk, |
| output LED2, |
| output LED3, |
| output LED4, |
| output LED5 |
| ); |
| |
| localparam BITS = 4; |
| localparam LOG2DELAY = $clog2($rtoi(`CLK_MHZ * 1e6)); |
| |
| reg [BITS+LOG2DELAY-1:0] counter = 0; |
| reg [BITS-1:0] outcnt = 0; |
| |
| always @(posedge clk) begin |
| counter <= counter + 1; |
| outcnt <= counter >> LOG2DELAY; |
| end |
| |
| assign {LED2, LED3, LED4, LED5} = outcnt; |
| endmodule |
