led1.txt

此源码可以在EASYFPGA是实现跑马灯程序

// my_led.v

module  led(
            clk48M,
            RSTn,
            LED
            );
input       	clk48M;
input       	RSTn;
output  [3:0]   LED;

reg     [3:0]   LED;
reg     [22:0]  Count;


always@(posedge clk48M or negedge RSTn)
begin
    if(!RSTn)
      begin
        LED<=4'h8;
        Count<=23'h0;
      end
    else
    begin
       Count<=Count+1;

        if(Count==23'hff_ff_ff)
           begin
             LED<=LED>>1;
             Count =0;
             if(LED==4'h0)
               LED<=4'h8;

           end
    end
end


endmodule