题解 | #游戏机计费程序#
游戏机计费程序
http://www.nowcoder.com/practice/50188fb7e23b4eee86f8c463c8284f5e
`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 <= 10'b0;
else if(set)
remain <= remain + money;
else if(!boost)
remain <= remain - 1'b1;
else if(boost)
remain <= remain - 10'd2;
else if(remain == 10'd1 && boost) // 如果此时剩下一块钱但是却是在减两块的模式下得清零;
remain <= 10'd0;
else
remain <= remain;
end
always @ (posedge clk or negedge rst_n)begin
if(!rst_n)
yellow <= 1'd0;
else if(remain > 10'd0 && remain <10'd10)
yellow <= 1'b1;
else
yellow <= 1'b0;
end
always @ (posedge clk or negedge rst_n)begin
if(!rst_n)
red <= 1'd0;
else if(remain == 10'd0)
red <= 1'b1;
else
red <= 1'b0;
end
endmodule