代碼如下:
/*信號定義
clk : 標準時鐘信號,本例中,其頻率為4Hz;
clk_lk: 產生鬧鈴聲、報時音的時鐘信號,本例中其頻率為1024Hz
mode: 功能控制信號;為0:計時功能;
為1:鬧鐘功能;
為2:手動校時功能;
turn : 若按鍵,在手動校時功能時,選擇調小時還是分鐘;
若長時間按住該鍵,還可以使秒信號清零,用於精確調時;
change: 若按鍵,手動調整時,每按壹次,計數器加1;
若長按,則連續快速加1,用於快速調時和定時;
hour,min,sec: 此三信號分別輸出並顯示時、分、秒信號,
皆采用BCD碼計數,分別驅動6個數碼顯示時間;
alert : 輸出到揚聲器的信號,用於產生鬧鈴聲和報時聲;
鬧鈴聲為持續20秒的急促的“滴滴滴”聲,若按住“change”鍵;
則可以屏蔽該音;整點報時音為“滴滴滴滴-嘟”四短壹長音;
LD_alert: 按發光二極管,指示是否設置了鬧鐘功能;
LD_hour : 按發光二極管,指示當前調整的是小時信號;
LD_min : 按發光二極管,指示當前調整的是分鐘信號。
*/
module clock(clk,clk_lk,mode,change,turn,alert,hour,min,sec,
LD_alert,LD_hour,LD_min);
input clk;
input clk_lk;
input mode; //mode信號控制系統在三種功能間轉換;
input change;
input turn;
output [7:0] hour;
output [7:0] min;
output [7:0] sec;
output alert;
output LD_alert;
output LD_hour;
output LD_min;
reg [7:0] hour;
reg [7:0] min;
reg [7:0] sec;
reg [7:0] hour1;
reg [7:0] min1;
reg [7:0] sec1;
reg [7:0] ahour;
reg [7:0] amin;
reg [1:0] m;
reg [1:0] fm;
reg [1:0] num1;
reg [1:0] num2;
reg [1:0] num3;
reg [1:0] num4;
reg [1:0] loop1;
reg [1:0] loop2;
reg [1:0] loop3;
reg [1:0] loop4;
reg [1:0] sound;
reg LD_hour;
reg LD_min;
reg clk_1Hz; //由4Hz的輸入時鐘產生1Hz的時基
reg clk_2Hz;
reg minclk;
reg hclk;
reg alert1;
reg alert2;
reg ear; //ear信號用於產生或屏蔽聲音
reg count1;
reg count2;
reg counta;
reg countb;
wire ct1;
wire ct2;
wire cta;
wire ctb;
wire m_clk;
wire h_clk;
always @ (posedge clk)
begin
clk_2Hz <= ~clk_2Hz;
if(sound==3) begin sound <=0; ear<=1; end
else begin sound <=sound+1; ear<=0; end
end
always @ (posedge clk_2Hz)
clk_1Hz <= ~clk_1Hz;
always //該進程產生count1,count2,counta,countb四個信號;
begin
case(m)
2: begin if(fm)
begin
count1<=change;
{LD_min,LD_hour}<=2;
end
else
begin
counta<=change;
{LD_min,LD_hour}<=1;
end
{count2,countb}<=0;
end
1: begin if(fm)
begin
count2<=change;
{LD_min,LD_hour}<=2;
end
else
begin
countb<=change;
{LD_min,LD_hour}<=1;
end
{count1,counta}<=2'b0;
end
default: {count1,count2,counta,countb,LD_min,LD_hour}<=0;
endcase
end
always @ (negedge clk) //若長時間按下“change”鍵,則生成“num1”信號用於連續加1
if(count2) begin
if(loop1==3) num1<=1;
else begin
loop1<=loop1+1;
num1<=0;
end
end
else begin loop1<=0;num1<=0; end
always @ (negedge clk) //產生num2信號
if(countb) begin
if(loop2==3) num2<=1;
else begin
loop2<=loop2+1;
num2<=0;
end
end
else begin loop2<=0; num2<=0; end
always @ (negedge clk)
if(count1) begin
if(loop3==3) num3<=1;
else begin
loop3<=loop3+1;
num3<=0;
end
end
else begin loop3<=0; num3<=0; end
always @ (negedge clk)
if(counta) begin
if(loop4==3) num4<=1;
else begin
loop4<=loop4+1;
num4<=0;
end
end
else begin loop4<=0; num4<=0; end
assign ct1=(num3&clk)|(!num3&m_clk); //ct1用於計時、校時中的分鐘計數
assign ct2=(num1&clk)|(!num1&count2); //ct2用於定時狀態下調整分鐘信號
assign ct1=(num4&clk)|(!num4&h_clk); //cta用於計時、校時中的小時計數
assign ct1=(num2&clk)|(!num3&countb); //ctb用於定時狀態下調整小時信號
always @ (posedge clk_1Hz) //秒計時和秒調整進程
if(!(sec1^8'h59)|trun&(!m))
begin
sec1<=0;
if(!(turn&(!m)))
minclk<=1;
end //按住turn鍵壹段時間,秒信號可以清零,該功能用於手動精確調時
else begin
if(sec1[3:0]==4'b1111)
begin
sec1[3:0]<=4'b0;
sec1[7:4]<=sec1[7:4]+1;
end
end
assign m_clk=minclk|count1;
always @ (posedge ct1) //分計時和分調整進程
begin
if(min1==8'h59) begin
min1<=0;
hclk<=1;
end
else begin
if(min1[3:0]==4'hf) begin
min1[3:0]<=0;
min1[7:4]<=min1[7:4]+1;
end
else
min1[3:0]<=min1[3:0]+1;
hclk<=0;
end
end
always @ (posedge cta) //小時計時和小時調整進程
if(hour1==8'h23)
hour1<=0;
else if(hour1[3:0]<=4'hf)
begin
hour1[7:4]<=hour1[7:4]+1;
hour1[3:0]<=0;
end
else
hour1[3:0]<=hour1[3:0]+1;
always @ (posedge ct2) //鬧鐘定時功能中的分鐘調節進程
if(amin==8'h59) amin<=0;
else if(amin[3:0]==4'hf)
begin
amin[3:0]<=0;
amin[7:4]<=amin[7:4]+1;
end
else
amin[3:0]<=amin[3:0]+1;
always @ (posedge ctb) //鬧鐘定時功能中的小時調節進程
if(ahour==8'h23)
ahour<=0;
else if(ahour[3:0]==4'hf)
begin
ahour[3:0]<=0;
ahour[7:4]<=ahour[7:4]+1;
end
else
ahour[3:0]<=ahour[3:0]+1;
always //鬧鈴功能
if((min1==amin)&&(hour1==ahour)&&(amin|ahour)&&(!change))
if(sec1<8'h20) //若按住“change"鍵不放,可屏蔽鬧鈴聲
alert<=1; //控制鬧鈴的時間長短
else
alert<=0;
always //時、分、秒的顯示控制
case(m)
3'b00: begin hour<=hour1;min<=min1;sec<=sec1; end
//計時狀態下的時、分、秒顯示
3'b01: begin hour<=ahour;min<=amin;sec<=8'hzz; end
//定時狀態下的時、分、秒顯示
3'b10: begin hour<=hour1;min<=min1;sec<=8'hzz; end
//校時狀態下的時、分、秒顯示
endcase
assign LD_alert=(ahour|amin)?1:0; //指示是否進行了鬧鈴的定時
assign alert =((alert)?clk_lk&clk:0)|alert2; //產生鬧鈴音或整點報時音
always //產生整點報時信號alert2
begin
if((min1==8'h59)&&(sec1>8'h54)||(!(min1|sec1)))
if(sec1>8'h54)
alert2<=ear&clk_lk; //產生短音
else
alert2<=!ear&clk_lk;//產生長音
else
alert2<=0;
endmodule