一、实现功能
1. 能正常完成时钟的时、分、秒走时；
2. 使用LED闪烁或者改变颜色等方式实现秒的指示，要求闪烁频率或者颜色切换频率为1Hz；
3. 使用两位七段数码管显示时和分，其切换方式为：默认显示“分钟”，按住K4键显示“小时”，按下K3显示秒针；
4. 关上开关sw2，使用K1和K2键调整时间，分别为“+”和“-”，则K1和K2调整“分钟”，当K4按下，则K1和K2调整“小时”，当K3按下，则K1和K2调整“秒针”；
5. 整点报时：当时间到达每个整点，则全彩LED以某种固定颜色按1Hz频率闪烁相应次数（按24小时制）；
6. 闹钟设置，将sw3开关设置为1，开始设置固定时钟和分钟，当时间计时到达时，八个led灯闪烁一分钟；
二、实验
1.整体结构
2.主函数
// Module Function:时钟设计
module time_clock (clk,rst,seg_led_1,seg_led_2,led,key,sw2,sw3,led_rgb1,led_rgb2);
input clk,rst;
input [3:0]key;
input sw2,sw3;
output reg [8:0] seg_led_1;
output reg [8:0] seg_led_2;
output reg [7:0] led;
output reg [2:0] led_rgb1=3'b 111;
output reg [2:0] led_rgb2=3'b 111;
reg [3:0] cnt1 ; //定义了一个4位的计数器
reg [3:0] count1;
reg [3:0] count_set_1;
reg [3:0] cnt2 ;
reg [3:0] count2;
reg [3:0] count_set_2;
reg [3:0] cnt3 ; //定义了一个4位的计数器
reg [3:0] count3;
reg [3:0] count_set_3;
reg [3:0] cnt4 ;
reg [3:0] count4;
reg [3:0] count_set_4;
reg [3:0] cnt5 ; //定义了一个4位的计数器
reg [3:0] count5;
reg [3:0] count_set_5;
reg [3:0] cnt6 ;
reg [3:0] count6;
reg [3:0] count_set_6;
reg [30:0]count_1s;
reg [30:0]count_05s;
reg [15 : 0] count;
reg [15 : 0] count0;
reg [8:0] seg [9:0];
wire clk1s; //定义一个中间变量，表示分频得到的时钟，用作计数器的触发
//间隔脉冲模块，产生一个 秒针 时钟信号
parameter N1 = 12000000;
always@(posedge clk) begin
if(!rst)
count_1s <= 0;
else if(count_1s == N1-1)
count_1s<=0;
else
count_1s<= count_1s + 1;
end
//间隔脉冲模块，产生一个调整 间隔 信号时钟信号
parameter N2 = 1500000;
always@(posedge clk) begin
if(!rst)
count_05s <= 0;
else if(count_05s == N2-1)
count_05s<= 0;
else
count_05s<= count_05s + 1;
end
divide #(.WIDTH(32),.N(12000000)) u2 ( //传递参数
.clk(clk),
.rst_n(rst), //例化的端口信号都连接到定义好的信号
.clkout(clk1s)
);
always @(posedge clk or negedge rst)
begin
if (!rst) //---------------------------------------------异步清零
begin
cnt1 <= 0;
cnt2<=0;
cnt3 <= 0;
cnt4<=0;
cnt5 <= 0;
cnt6<=0;
end
//----------------------------------------开始计时
else
begin
if(sw2==1)//sw2调整时间的开关 1：开始计时 0：调整时间 sw3为闹钟设置开关 设置闹钟模式sw3：1 退出设置闹钟模式sw3：0
begin
if(count_1s==N1-1 )
begin
//秒
if((cnt2==5)&&(cnt1==9))
begin
cnt1<=0;
cnt2<=0;
//分钟
if((cnt4==5)&&(cnt3==9))
begin
cnt3<=0;
cnt4<=0;
//小时
if((cnt6==2)&&(cnt5==3))
begin
cnt5<=0;
cnt6<=0;
end
else if(cnt5==9)
begin
cnt5<=0;
cnt6<=cnt6+1;
end
else
begin
cnt5<=cnt5+1;
end
//小时
end
else if(cnt3==9)
begin
cnt3<=0;
cnt4<=cnt4+1;
end
else
begin
cnt3<=cnt3+1;
end
end
//分钟
else if(cnt1==9)
begin
cnt1<=0;
cnt2<=cnt2+1;
end
else
begin
cnt1<=cnt1+1;
end
//秒
end
end
//-------------------------------------------------------------------暂停调整时间
if(sw2==0 && sw3==0)
begin
if(key[2]==1 && key[3]==1)//-----------------------------------------------调整分针
begin
if( key[0]==0 )
begin
if(count_05s==N2-1)
begin
if((cnt4==5)&&(cnt3==9))
begin
cnt3<=0;
cnt4<=0;
end
else if(cnt3==9 )
begin
cnt3<=0;
cnt4<=cnt4+1;
end
else
begin
cnt3<=cnt3+1;
end
end
end
else if(key[1]==0)
begin
if(count_05s==N2-1)
begin
if(cnt3==0 && cnt4==0)
begin
cnt3<=9;
cnt4<=5;
end
else if(cnt3==0)
begin
cnt3<=9;
cnt4<=cnt4-1;
end
else
cnt3<=cnt3-1;
end
end
else
begin
cnt3<=cnt3;
cnt4<=cnt4;
end
end
else if(key[2]==1 && key[3]==0)//-----------------------------------------------调整时针
begin
if( key[0]==0 )
begin
if(count_05s==N2-1)
begin
if((cnt6==2)&&(cnt5==3))
begin
cnt5<=0;
cnt6<=0;
end
else if(cnt5==9)
begin
cnt5<=0;
cnt6<=cnt6+1;
end
else
begin
cnt5<=cnt5+1;
end
end
end
else if(key[1]==0)
begin
if(count_05s==N2-1)
begin
if(cnt5==0 && cnt6==0)
begin
cnt5<=3;
cnt6<=2;
end
else if(cnt5==0)
begin
cnt5<=9;
cnt6<=cnt6-1;
end
else
cnt5<=cnt5-1;
end
end
else
begin
cnt5<=cnt5;
cnt6<=cnt6;
end
end
else if(key[2]==0 && key[3]==1)//-----------------------------------------------调整秒针
begin
if( key[0]==0 )
begin
if(count_05s==N2-1)
begin
if((cnt2==5)&&(cnt1==9))
begin
cnt1<=0;
cnt2<=0;
end
else if(cnt1==9)
begin
cnt1<=0;
cnt2<=cnt2+1;
end
else
begin
cnt1<=cnt1+1;
end
end
end
else if(key[1]==0)
begin
if(count_05s==N2-1)
begin
if(cnt1==0 && cnt2==0)
begin
cnt1<=9;
cnt2<=5;
end
else if(cnt1==0)
begin
cnt1<=9;
cnt2<=cnt2-1;
end
else
cnt1<=cnt1-1;
end
end
else
begin
cnt1<=cnt1;
cnt2<=cnt2;
end
end
end
//-----------------------------------------------设置闹钟
if(sw3==1 )
begin
if(key[2]==1 && key[3]==1)//-----------------------------------------------调整分针
begin
if( key[0]==0 )
begin
if(count_05s==N2-1)
begin
if((count_set_4==5)&&(count_set_3==9))
begin
count_set_3<=0;
count_set_4<=0;
end
else if(count_set_3==9 )
begin
count_set_3<=0;
count_set_4<=count_set_4+1;
end
else
begin
count_set_3<=count_set_3+1;
end
end
end
else if(key[1]==0)
begin
if(count_05s==N2-1)
begin
if(count_set_3==0 && count_set_4==0)
begin
count_set_3<=9;
count_set_4<=5;
end
else if(count_set_3==0)
begin
count_set_3<=9;
count_set_4<=count_set_4-1;
end
else
count_set_3<=count_set_3-1;
end
end
else
begin
count_set_3<=count_set_3;
count_set_4<=count_set_4;
end
end
else if(key[2]==1 && key[3]==0)//-----------------------------------------------调整时针
begin
if( key[0]==0 )
begin
if(count_05s==N2-1)
begin
if((count_set_6==2)&&(count_set_5==3))
begin
count_set_5<=0;
count_set_6<=0;
end
else if(count_set_5==9)
begin
count_set_5<=0;
count_set_6<=count_set_6+1;
end
else
begin
count_set_5<=count_set_5+1;
end
end
end
else if(key[1]==0)
begin
if(count_05s==N2-1)
begin
if(count_set_5==0 && count_set_6==0)
begin
count_set_5<=3;
count_set_6<=2;
end
else if(count_set_5==0)
begin
count_set_5<=9;
count_set_6<=count_set_6-1;
end
else
count_set_5<=count_set_5-1;
end
end
else
begin
count_set_5<=count_set_5;
count_set_6<=count_set_6;
end
end
end
end
end
//--------------------------------------------------------------------数码管显示
//在过程块中只能给reg型变量赋值，Verilog中有两种过程块always和initial
initial //initial和always不同，其中语句只执行一次
begin
seg[0] = 9'h3f; //对存储器中第一个数赋值9'b00_0011_1111,相当于共阴极接地，DP点变低不亮，7段显示数字 0
seg[1] = 9'h06; //7段显示数字 1
seg[2] = 9'h5b; //7段显示数字 2
seg[3] = 9'h4f; //7段显示数字 3
seg[4] = 9'h66; //7段显示数字 4
seg[5] = 9'h6d; //7段显示数字 5
seg[6] = 9'h7d; //7段显示数字 6
seg[7] = 9'h07; //7段显示数字 7
seg[8] = 9'h7f; //7段显示数字 8
seg[9] = 9'h6f; //7段显示数字 9
end
always @(posedge clk)
begin
if(sw3==0)
begin
if(key[2]==1 && key[3]==0)
begin
count5<=cnt5;
count6<=cnt6;
seg_led_1<=seg[count6];
seg_led_2<=seg[count5];
end
else if(key[2]==0 && key[3]==1)
begin
count1<=cnt1;
count2<=cnt2;
seg_led_1<=seg[count2];
seg_led_2<=seg[count1];
end
else
begin
count4<=cnt4;
count3<=cnt3;
seg_led_1<=seg[count4];
seg_led_2<=seg[count3];
end
end
else
begin
if(key[2]==1 && key[3]==0)
begin
count5<=count_set_5;
count6<=count_set_6;
seg_led_1<=seg[count6];
seg_led_2<=seg[count5];
end
else if(key[2]==0 && key[3]==1)
begin
count1<=count_set_1;
count2<=count_set_2;
seg_led_1<=seg[count2];
seg_led_2<=seg[count1];
end
else
begin
count4<=count_set_4;
count3<=count_set_3;
seg_led_1<=seg[count4];
seg_led_2<=seg[count3];
end
end
end
//--------------------------------------------整点--三色灯闪烁
always @(posedge clk1s)
begin
led_rgb2[0]<=~led_rgb2[0];//--------------------------------------------三色灯秒钟闪烁
if(cnt3==0 && cnt4==0)
begin
led_rgb1[0]<=~led_rgb1[0];
end
else
begin
led_rgb1[0]<=1;
end
end
//-------------------------------------------闹钟闪烁
always @(posedge clk1s)
begin
if(count_set_3 == cnt3 && count_set_4 == cnt4 && count_set_5 == cnt5 && count_set_6 == cnt6)
begin
led<=~led;
end
else
begin
led<=8'b 11111111;
end
end
endmodule3.分频器
// Module Function:任意整数时钟分频
module divide ( clk,rst_n,clkout);
input clk,rst_n; //输入信号，其中clk连接到FPGA的C1脚，频率为12MHz
output clkout; //输出信号，可以连接到LED观察分频的时钟
//parameter是verilog里常数语句
parameter WIDTH = 24; //计数器的位数，计数的最大值为 2**WIDTH-1
parameter N = 12_000_000; //分频系数，请确保 N < 2**WIDTH-1，否则计数会溢出
reg [WIDTH-1:0] cnt_p,cnt_n; //cnt_p为上升沿触发时的计数器，cnt_n为下降沿触发时的计数器
reg clk_p,clk_n; //clk_p为上升沿触发时分频时钟，clk_n为下降沿触发时分频时钟
//上升沿触发时计数器的控制
always @ (posedge clk or negedge rst_n ) //posedge和negedge是verilog表示信号上升沿和下降沿
//当clk上升沿来临或者rst_n变低的时候执行一次always里的语句
begin
if(!rst_n)
cnt_p<=0;
else if (cnt_p==(N-1))
cnt_p<=0;
else cnt_p<=cnt_p+1; //计数器一直计数，当计数到N-1的时候清零，这是一个模N的计数器
end
//上升沿触发的分频时钟输出,如果N为奇数得到的时钟占空比不是50%；如果N为偶数得到的时钟占空比为50%
always @ (posedge clk or negedge rst_n)
begin
if(!rst_n)
clk_p<=0;
else if (cnt_p<(N>>1)) //N>>1表示右移一位，相当于除以2去掉余数
clk_p<=0;
else
clk_p<=1; //得到的分频时钟正周期比负周期多一个clk时钟
end
//下降沿触发时计数器的控制
always @ (negedge clk or negedge rst_n)
begin
if(!rst_n)
cnt_n<=0;
else if (cnt_n==(N-1))
cnt_n<=0;
else cnt_n<=cnt_n+1;
end
//下降沿触发的分频时钟输出，和clk_p相差半个时钟
always @ (negedge clk)
begin
if(!rst_n)
clk_n<=0;
else if (cnt_n<(N>>1))
clk_n<=0;
else
clk_n<=1; //得到的分频时钟正周期比负周期多一个clk时钟
end
assign clkout = (N==1)?clk:(N[0])?(clk_p&clk_n):clk_p; //条件判断表达式
//当N=1时，直接输出clk
//当N为偶数也就是N的最低位为0，N（0）=0，输出clk_p
//当N为奇数也就是N最低位为1，N（0）=1，输出clk_p&clk_n。正周期多所以是相与
endmodule 4.广角分配文章来源：https://www.toymoban.com/news/detail-504655.html
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