题解 | #游戏机计费程序#

1. 根据boost类型确定每分钟/周期消费金额，注意充值所在分钟/周期是不消费的。
2. 两个灯(red yellow)不能同时亮起，先判断红灯是否满足条件，再判断黄灯。

完整代码

`timescale 1ns/1ns

module game_count
    (
		input rst_n, //异位复位信号，低电平有效
        input clk, 	//时钟信号
        input [9:0]money,
        input set,
		input boost,
		output reg[9:0]remain,
		output reg yellow,
		output reg red
    );
    
    always@(posedge clk or negedge rst_n)begin
        if(~rst_n)
            remain <= 0;
        else begin
            if(boost==0)
                remain <= set==1? remain+money: remain-1;
            else if(boost==1)
                remain <= set==1? remain+money: remain-2;
        end
    end
    
    always@(posedge clk or negedge rst_n)begin
        if(~rst_n)begin
            yellow <= 0;
            red <= 0;
        end
        else begin
            if(remain < 1)begin
                yellow <= 0;
                red <= 1;
            end
            else if(remain < 10)begin
                yellow <= 1;
                red <= 0;
            end
            else begin
                yellow <= 0;
                red <= 0;
            end
        end
    end

endmodule