我寫的一個十進位制計數，可以復位，置數，使能，雙向計數，請參考

`timescale 1ns/100ps

module count(

clk,

nrst,

ncs,

s,

load,

load_data,

q

);

input clk;

input nrst;

input ncs;

input s;

input load;

input [3:0] load_data;

output [3:0] q;

reg [3:0] q;

always @(posedge clk or negedge nrst) begin

if(!nrst) begin

q

end else if(!ncs) begin

q

end else if(load==1"b1) begin

q

end else if(s==1"b1) begin

if(q==4"b1001) begin

q

end else begin

q

end

end else if(s==1"b0) begin

if(q==4"b0000) begin

q

end else begin

q

end

end

end

endmodule