module blinky ( input clki, output led1, output led2, output led3, output led4, output led5 ); BUFGCTRL clk_gb ( .I0(clki), .CE0(1'b1), .S0(1'b1), .O(clk) ); localparam BITS = 5; localparam LOG2DELAY = 21; reg [BITS+LOG2DELAY-1:0] counter = 0; reg [BITS-1:0] outcnt; always @(posedge clk) begin counter <= counter + 1; outcnt <= counter >> LOG2DELAY; end assign {led1, led2, led3, led4, led5} = outcnt ^ (outcnt >> 1); endmodule