FPGA项目实现：秒表设计

项目要求

设计一个时钟秒表，共六个数码管，前两位显示分钟，中间两位显示时间秒，后两位显示毫秒的高两位，可以通过按键来开始、暂停以及重新开始秒表的计数。

项目设计

为完成此项目共设计四个模块，按键消抖模块、时钟计时器模块、数码管显示模块以及顶层文件模块，详细代码设计如下：

按键消抖模块：

/** @Description: 按键销抖模块(延迟方法销抖)* @Author: Fu Yu* @Date: 2023-08-01 14:31:19* @LastEditTime: 2023-08-01 16:29:44* @LastEditors: Fu Yu*/module key_filter (input       wire        clk         ,input       wire        rst_n       ,input       wire        key_in      ,//按键输入，低有效output      wire        key_down       //按键输出,高有效
);parameter MAX_20MS = 20'd999_999;//20msreg key_r;//同步
reg key_r1;//打拍
reg key_r2;
wire nedge;//下降沿reg key_down_r;//保存key_down信号reg [19:0]  cnt_20ms;
reg flag;//计数开始标志信号
wire add_cnt_20ms;
wire end_cnt_20ms;//****************************************************************
//--同步打拍，检测下降沿
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginkey_r <= 1'b1;key_r1 <= 1'b1;key_r2 <= 1'b1;endelse beginkey_r <= key_in;key_r1 <= key_r;key_r2 <= key_r1;end
end//下降沿检测
assign nedge = ~key_r1 & key_r2;//****************************************************************
//--flag信号定义
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginflag <= 1'b0;endelse if(nedge) beginflag <= 1'b1;endelse if(end_cnt_20ms) beginflag <= 1'b0;endelse beginflag <= flag;end
end//****************************************************************
//--计数
//****************************************************************
always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_20ms <= 20'd0;end else if(add_cnt_20ms)begin if(end_cnt_20ms)begin cnt_20ms <= 20'd0;endelse begin cnt_20ms <= cnt_20ms + 1'b1;end end
end assign add_cnt_20ms = flag;
assign end_cnt_20ms = add_cnt_20ms && cnt_20ms == MAX_20MS;//****************************************************************
//--key_down
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginkey_down_r <= 1'b0;endelse if(end_cnt_20ms) beginkey_down_r <= ~key_r2;endelse beginkey_down_r <= 1'b0;end
endassign key_down = key_down_r;endmodule //key_filter

时钟计时器模块：

/** @Description: 通过输入的按键控制计数开始与暂停，实现秒表设计（毫秒、秒、分计时）* @Author: Fu Yu* @Date: 2023-08-01 14:46:43* @LastEditTime: 2023-08-01 15:53:12* @LastEditors: Fu Yu*/module counter_time (input       wire        clk         ,input       wire        rst_n       ,input       wire        key_in      ,//销抖后的脉冲信号，高有效output      wire [23:0] din_out         //输出当前计数的值
);parameter MAX_1MS = 16'd49_999;//1ms
parameter MAX_1S = 10'd999;//1ms*1000 = 1s
parameter MAX_1MIN = 6'd59;//1s*60 = 1min
parameter MAX_1H = 6'd59;//1min*60 = 1hreg flag;//开始、暂停结束信号reg [15:0] cnt_1ms;
wire add_cnt_1ms;
wire end_cnt_1ms;reg [9:0] cnt_1s;
wire add_cnt_1s;
wire end_cnt_1s;reg [5:0] cnt_1min;
wire add_cnt_1min;
wire end_cnt_1min;reg [5:0] cnt_1h;
wire add_cnt_1h;
wire end_cnt_1h;reg [7:0] data_min;//保存此时有多少分钟
reg [7:0] data_s;//保存此时有多少秒
reg [7:0] data_ms;//保存此时有多少毫秒,只取高两位//****************************************************************
//--flag
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginflag <= 1'b0;endelse if (key_in) beginflag <= ~flag;endelse beginflag <= flag;end
end//****************************************************************
//--1ms计数器
//****************************************************************
always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_1ms <= 16'd0;end else if(add_cnt_1ms)begin if(end_cnt_1ms)begin cnt_1ms <= 16'd0;endelse begin cnt_1ms <= cnt_1ms + 1'b1;end end
end assign add_cnt_1ms = flag;
assign end_cnt_1ms = add_cnt_1ms && cnt_1ms == MAX_1MS;//****************************************************************
//--1s计数器
//****************************************************************always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_1s <= 10'd0;end else if(add_cnt_1s)begin if(end_cnt_1s)begin cnt_1s <= 10'd0;endelse begin cnt_1s <= cnt_1s + 1'b1;end end
end assign add_cnt_1s = end_cnt_1ms;
assign end_cnt_1s = add_cnt_1s && cnt_1s == MAX_1S ;
//&& end_cnt_1ms//****************************************************************
//--1min计数器
//****************************************************************always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_1min <= 6'd0;end else if(add_cnt_1min)begin if(end_cnt_1min)begin cnt_1min <= 6'd0;endelse begin cnt_1min <= cnt_1min + 1'b1;end end
end assign add_cnt_1min = end_cnt_1s;
assign end_cnt_1min = add_cnt_1min && cnt_1min == MAX_1MIN ;
//&& end_cnt_1s
//****************************************************************
//--1h计数器
//****************************************************************
always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_1h <= 6'd0;end else if(add_cnt_1h)begin if(end_cnt_1h)begin cnt_1h <= 6'd0;endelse begin cnt_1h <= cnt_1h + 1'b1;end end
end assign add_cnt_1h = end_cnt_1min;
assign end_cnt_1h = add_cnt_1h && cnt_1h == MAX_1H;
// && end_cnt_1min
//****************************************************************
//--din_out
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) begindata_min <= 8'd0;data_s <= 8'd0;data_ms <= 8'd0;endelse begindata_min <= cnt_1h;data_s <= cnt_1min;data_ms <= cnt_1s/10;end
endassign din_out = {data_min,data_s,data_ms};endmodule //counter_time

数码管显示模块：

/** @Description: 数码管显示时钟，前两位显示分钟，中间两位显示秒，最后两位显示毫秒* @Author: Fu Yu* @Date: 2023-08-01 15:19:52* @LastEditTime: 2023-08-01 16:22:40* @LastEditors: Fu Yu*/module seg_sel (input       wire        clk         ,input       wire        rst_n       ,input       wire [23:0] din         ,output      wire [5:0]  sel         ,//位选信号output      wire [7:0]  dig             //段选信号
);parameter MAX_1MS = 16'd49_999;//1msparameter   ZERO  = 7'b100_0000,ONE   = 7'b111_1001,TWO   = 7'b010_0100,THREE = 7'b011_0000,FOUR  = 7'b001_1001,FIVE  = 7'b001_0010,SIX   = 7'b000_0010,SEVEN = 7'b111_1000,EIGHT = 7'b000_0000,NINE  = 7'b001_0000;reg [5:0]   point_n;//小数点位置
reg point_n_r;reg [15:0] cnt_1ms;
wire add_cnt_1ms;
wire end_cnt_1ms;reg [5:0]   sel_r;
reg [7:0]   dig_r;
reg [3:0]   disp_data   ;//每一位数码管显示的数值//****************************************************************
//--1ms计数器
//****************************************************************
always @(posedge clk or negedge rst_n)begin if(!rst_n)begincnt_1ms <= 16'd0;end else if(add_cnt_1ms)begin if(end_cnt_1ms)begin cnt_1ms <= 16'd0;endelse begin cnt_1ms <= cnt_1ms + 1'b1;end end
end assign add_cnt_1ms = 1'b1;
assign end_cnt_1ms = add_cnt_1ms && cnt_1ms == MAX_1MS;//****************************************************************
//--小数点
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginpoint_n <= 6'b111111;endelse beginpoint_n <= 6'b110101;end
end//****************************************************************
//--sel信号
//****************************************************************
always @(posedge clk or negedge rst_n) beginif(!rst_n) beginsel_r <= 6'b111110;endelse if(end_cnt_1ms) beginsel_r <= {sel_r[4:0],sel_r[5]};//循环左移end
endassign sel = sel_r;//****************************************************************
//--disp_data
//****************************************************************always @(posedge clk or negedge rst_n)begin if(!rst_n)begindisp_data <= 'd0;point_n_r <= 1'b1;end else begin case (sel_r)6'b111_110 : begin disp_data <= din[23:16]/10  ; point_n_r <= point_n[0]; end//第一位数码管显示的数值6'b111_101 : begin disp_data <= din[23:16]%10  ; point_n_r <= point_n[1]; end6'b111_011 : begin disp_data <= din[15:8]/10 ; point_n_r <= point_n[2]; end6'b110_111 : begin disp_data <= din[15:8]%10 ; point_n_r <= point_n[3]; end6'b101_111 : begin disp_data <= din[7:0]/10 ; point_n_r <= point_n[4]; end6'b011_111 : begin disp_data <= din[7:0]%10 ; point_n_r <= point_n[5]; enddefault: disp_data <= 'd0;endcaseend end//****************************************************************
//--dig
//****************************************************************
always @(*)begin case (disp_data)0 :  dig_r <= {point_n_r,ZERO  };1 :  dig_r <= {point_n_r,ONE   };2 :  dig_r <= {point_n_r,TWO   };3 :  dig_r <= {point_n_r,THREE };4 :  dig_r <= {point_n_r,FOUR  };5 :  dig_r <= {point_n_r,FIVE  };6 :  dig_r <= {point_n_r,SIX   };7 :  dig_r <= {point_n_r,SEVEN };8 :  dig_r <= {point_n_r,EIGHT };9 :  dig_r <= {point_n_r,NINE  };default: dig_r <= 8'hff;endcaseendassign dig = dig_r;endmodule //seg_sel

顶层文件模块：

module top (input       wire        clk         ,input       wire        rst_n       ,input       wire        key_in      ,output      wire [5:0]  sel         ,output      wire [7:0]  dig             
);wire key;
wire [23:0] data;key_filter u_key_filter(.       clk        (clk) ,.       rst_n       (rst_n),.       key_in      (key_in),.       key_down     (key)
);counter_time u_counter_time(. clk        (clk) ,. rst_n      (rst_n) ,. key_in     (key) ,. din_out      (data)
);seg_sel u_seg_sel(. clk      (clk)   ,. rst_n     (rst_n)  ,. din       (data)  ,. sel        (sel) ,. dig        (dig)  
);endmodule //top

效果展示：

秒表