clkout2.v

（1）当乡村公路无车时

module clkout2(clkin,clkout);
input clkin;
output clkout;
reg clkout;
reg [10:0]j;
always@(posedge clkin)
begin
if(j==11'd500)
begin
clkout<=!clkout;
j<=0;
end 
else j<=j+1;
end

endmodule