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	[2:0]	money;//0.5Y = 001,1Y=010,

always@(posedge clk or negedge rst)
	if(!rst)
		money	<=	3'd0;
	else	if((!sel && money>=3) || (sel && money>=5))
		money	<=	3'd0;
	else	if(d1)
		money	<=	money + 1;
	else	if(d2)
		money	<=	money + 2;
	else
		money	<=	money;
//output
always@(posedge clk or negedge rst)
	if(!rst)
		begin
			out1	<=	1'b0;
			out2	<=	1'b0;
			out3	<=	1'b0;
		end
	else	if(!sel && money>=3)
		begin
			out1	<=	1'b1;
			out2	<=	1'b0;
			out3	<=	money - 3'd3;
		end	
	else	if(sel && money>=5)
		begin
			out1	<=	1'b0;
			out2	<=	1'b1;
			out3	<=	money - 3'd5;
		end	
	else
		begin
			out1	<=	1'b0;
			out2	<=	1'b0;
			out3	<=	1'b0;
		end

//*************code***********//
endmodule