题解 | #游戏机计费程序#

`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)begin
        remain <= 0;
    end
    else begin
        if(set)begin
            remain <= remain + money;
        end
        else begin
            if(boost)begin
                remain <= remain - 2;
            end
            else begin
                remain <= remain - 1;
            end
        end
    end
end

always @(posedge clk or negedge rst_n)begin
    if(!rst_n)begin
        yellow <= 1'b0;
    end
    else begin
        if(remain < 10 && remain > 0)begin
            yellow <= 1'b1;
        end
        else begin
            yellow <= 1'b0;
        end
    end
end

always @(posedge clk or negedge rst_n)begin
    if(!rst_n)begin
        red <= 1'b0;
    end
    else begin
        if(boost)begin
            if(remain < 2)begin
                red <= 1'b1;
            end
            else begin
                red <= 1'b0;
            end
        end
        else begin
            if(remain < 1)begin
                red <= 1'b1;
            end
            else begin
                red <= 1'b0;
            end
        end       
    end
end

endmodule