verilog实现数码管静态显示

一、任务要求

六个数码管同时间隔0.5s显示0-f。要求：使用一个顶层模块，调用计时器模块和数码管静态显示模块。

二、实验代码

module time_count(
	input	     clk  ,//50MHz时钟信号
	input		 rst_n,//复位信号
	output	reg  flag//一个时钟周期的脉冲信号
);
parameter	 MAX_NUM = 25'd25_000_000;//计数器最大计数值
reg  [24:0]	 cnt                     ; //时钟分频计数器

//计数器对时钟计数，每0.5s，输出一个时钟周期脉冲信号
always @(posedge clk or negedge rst_n)begin
	if(!rst_n)begin//按复位时
		cnt <= 25'd0;//计数器清零
	end
	else if(cnt == MAX_NUM - 1'b1)begin//如果没到时间
		cnt <= 0;//计数器正常累计+1
	end
	else begin //否则到时间	
		cnt <= cnt + 1'b1;
	end
end

always @(posedge clk or negedge rst_n) begin
    if(~rst_n) begin
       flag <= 1'b0;//信号为0
    end
    else if(cnt == MAX_NUM - 1'b1)begin
        flag <= 1'b1;//信号为0
    end
    else begin
       flag <= 1'b0;//信号变为1
    end
end

endmodule

module	seg_led_static(
	input		      clk     ,
	input		      rst_n   ,
	input		      flag    ,
	output	reg [5:0] sel     ,//数码管位选信号
	output	reg [7:0] seg  //数码管段选信号
);
parameter   ZERO =  8'b1100_0000,
			ONE  =  8'b1111_1000,
			TWO  =  8'b1010_0100,
			THREE =  8'b1011_0000,
			FOUR = 8'b1001_1001,
			FIVE =  8'b1001_0010,
			SIX =  8'b1000_0010,
			SEVEN =  8'b1111_1000,
			EIGHT =  8'b1000_0000,
			NINE =  8'b1001_0000,
			A =  8'b1000_1000,
			B =  8'b1000_0011,
			C =  8'b1100_0110,
			D =  8'b1010_0001,
			E =  8'b1000_0110,
			F =  8'b1000_1110;
reg [3:0]	num;//数码管显示十六进制数
//控制数码管位选信号(注:低电平有效),选中所有的数码管
always @(posedge clk or negedge rst_n)begin
	if(!rst_n)//如果按复位键0
		sel <= 6'b111111;//则默认为高电平
	else 
		sel <= 6'b000000;//否则为低电平
end
//每次通知信号flag到达时，数码管计数加1
always @(posedge clk or negedge rst_n)begin
	if(!rst_n)
		num <=	4'h0;
	else if(flag)begin
		if(num < 4'hf)
			num <= num + 1'h1;
		else 
			num <= 4'h0;
	end
	else begin
		num <= num;
	end
end
//根据数码管显示的数值，控制段选信号
always @(posedge clk or negedge rst_n)begin
	if(!rst_n)
		seg <= 8'b0;
	else begin
		case(num)//匹配16进制数
			4'h0:    seg <= 8'b1100_0000;//匹配到后参考共阳极真值表
	        4'h1:    seg <= 8'b1111_1001;
	        4'h2:    seg <= 8'b1010_0100;
	        4'h3:    seg <= 8'b1011_0000;
	        4'h4:    seg <= 8'b1001_1001;
	        4'h5:    seg <= 8'b1001_0010;
	        4'h6:    seg <= 8'b1000_0010;
	        4'h7:    seg <= 8'b1111_1000;
	        4'h8:    seg <= 8'b1000_0000;
	        4'h9:    seg <= 8'b1001_0000;
	        4'ha:    seg <= 8'b1000_1000;
	        4'hb:    seg <= 8'b1000_0011;
	        4'hc:    seg <= 8'b1100_0110;
	        4'hd:    seg <= 8'b1010_0001;
	        4'he:    seg <= 8'b1000_0110;
	        4'hf:     seg <= 8'b1000_1110;
	      	default : seg <= 8'b1100_0000;
		endcase
	end
end
endmodule

module  top_seg_led_static(
	input	 	         clk  ,//50MHz系统时钟
	input		         rst_n,//系统复位信号(低有效)
	output		[5:0]	 sel  ,//数码管位选
	output	    [7:0]	 seg//数码管段选
);
 
parameter	MAX_NUM = 25'd25_000_000;// 数码管变化的时间间隔0.5s
wire		add_flag				;// 数码管变化的通知信号
//每隔0.5s产生一个时钟周期的脉冲信号
time_count #(.MAX_NUM(MAX_NUM)) u_time_count(
	.clk		(clk)  ,//50MHz时钟信号
	.rst_n		(rst_n),//复位信号
	.flag		(add_flag)//一个时钟周期的脉冲信号
);
//每当脉冲信号到达时，使数码管显示的数值加1
seg_led_static u_seg_led_static(
	.clk		(clk)	  ,
	.rst_n		(rst_n)	  ,
	.flag	    (add_flag),
	.sel		(sel)	  ,
	.seg		(seg)
);
endmodule

三、仿真代码

`timescale 1ns/1ns
module top_seg_led_static_tb();

reg   		 	clk    ;
reg  		 	rst_n  ;
wire    [5:0]	sel	   ;
wire 	[7:0]  	seg    ;
parameter CYCLE = 5'd20;//周期20ns
parameter MAX_NUM = 8'd100;//调小间隔时间100*20ns
always #(CYCLE/2) clk = ~clk;//翻转时钟

initial begin
	clk   = 0		   ;//时钟初始为0
	rst_n = 0		   ;//复位初始为0
	#(CYCLE)		   ;//延迟20ns
	rst_n = 1		   ;//复位置1
	#(16*MAX_NUM*CYCLE);//显示0-f时间
	$stop			   ;//停止
	
	
end 
top_seg_led_static#(.MAX_NUM (MAX_NUM))	u_top_seg_led_static(
.clk  	(clk)  ,//50MHz系统时钟
.rst_n	(rst_n),//系统复位信号(低有效)
.sel  	(sel)  ,//数码管位选
.seg	(seg)	//数码管段选
);
endmodule