题解 | 自动贩售机2

`timescale 1ns/1ns

module seller2(
	input wire clk  ,
	input wire rst  ,
	input wire d1 ,
	input wire d2 ,
	input wire sel ,
	
	output reg out1,
	output reg out2,
	output reg out3
);
//*************code***********//

reg [3:0] cnt;
    always@(posedge clk or negedge rst)begin
        if(!rst)begin
            cnt <= 0;
            out1 <= 0;
            out2 <= 0;
			out3 <= 0;
        end
        else begin
			if(sel==0)begin
				if(d1) cnt <= cnt + 1;
            	else if(d2) cnt <= cnt + 2;
            	else if(cnt == 3)begin
					out1 <= 1;
					out2 <= 0;
					out3 <= 0;
					cnt <= 0;
				end
            	else if(cnt == 4)begin
					out1 <= 1;
					out2 <= 0;
					out3 <= 1;
					cnt <= 0;
				end
				else begin
            	    out1 <= 0;
            	    out2 <= 0;
            	    out3 <= 0;
            	end
			end
			else begin
                if(d1) cnt <= cnt + 1;
            	else if(d2) cnt <= cnt + 2;
            	else if(cnt == 5)begin
					out1 <= 0;
					out2 <= 1;
					out3 <= 0;
					cnt <= 0;
				end
            	else if(cnt == 6)begin
					out1 <= 0;
					out2 <= 1;
					out3 <= 1;
					cnt <= 0;
				end
				else begin
            	    out1 <= 0;
            	    out2 <= 0;
            	    out3 <= 0;
            	end
            end
        end
    end
//*************code***********//
endmodule