EZ 收徒

module top_module (
    input clk,
    input reset,   // Synchronous active-high reset
    output [3:1] ena,
    output [15:0] q);

    always@(posedge clk)begin
        if(reset)begin
            ena <= 0;
        end
        else begin
            if(q[3:0]==8)
                ena[1]<=1;
            else
                ena[1]<=0;
            if(q[3:0]==8&&q[7:4]==9)
                ena[2]<=1;
            else
                ena[2]<=0;
            if(q[3:0]==8&&q[7:4]==9&&q[11:8]==9)
                ena[3]<=1;
            else
                ena[3]<=0;
            
        end
    end

    autoAdder adder1(1, clk, reset, q[3:0]);
    autoAdder adder2(ena[1], clk, reset, q[7:4]);
    autoAdder adder3(ena[2], clk, reset, q[11:8]);
    autoAdder adder4(ena[3], clk, reset, q[15:12]);

endmodule


module autoAdder(
    input ena,
    input clk,
    input reset,
    output [3:0]q
);
    always@(posedge clk)begin
        
            if(reset)begin
                q <= 0;
            end
            else if(ena) begin
                if(q==4'd9)
                    q<=0;
                else
                    q <= q + 1;
            end
            else
                q <= q;
        
    end

endmodule