【转载】FPGA Verilog HDL 系列实例 电子琴 电子钟

这是我从论坛上转载过来的，觉得写的还不错，暂时先转载过来，等有空的时候再验证下。

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控制说明：
　　1、电子琴：程序设计采用八个输入端口，分别与实验箱上的按键8~1引脚相连接，采用一个输出端口，与扬声器的引脚连接，时钟频率采用6MHz和4Hz。按键7~1分别用于中音的七个音符的发音（DO，RE，MI，FA，SO，LA，SI），按键8用于控制乐曲的播放。程序的编写采用状态机的编写方法，对按键的状态进行判断，对应相应的音符或乐曲。
　　2、电子钟：程序的设计模块有：时钟初始化模块、时钟工作模块、时钟设置模块、闹钟设置模块、闰年的月份天数判断模块、数码管显示模块、闹钟铃声模块及其它的设置模块。程序使用8个输入分别与8个按键连接，用按键8对应时钟工作状态（work_state），当work_state为0时，时钟正常工作，当work_state为1时，进入时钟设置状态。按键7对应输入端口display_set控制时钟显示状态（display_state），每按2次（用于产生上升沿触发）则数码管的输出不同。Display_state与work_state相结合使用，以区分设置的参数。按键6~4对应输入个脚in_set，该参数共有三位，用以表示三个状态：state_yorh （设置年或小时）、state_morm（设置月份或分钟）、 state_dors（设置日期或秒钟）。按键3~2对应数值设置端口up各down。Up用于产生上升沿触发，当down为0时，则每一个上升沿产生时，相应的参数加1，当down为1时，则每一个上升沿产生时，相应的参数减1。按键1与输入端口clock_on相连，用于闹钟的开与关，当 clock_on为1时开闹钟，否则关闹钟。扬声器与输出端口speaker相连，用于输出闹钟铃声。

附录：源程序

一、 电子琴： 
module piano(in,clk_6MHz,clk_4Hz,song,speaker); 
input in,clk_6MHz,clk_4Hz,song; 
output speaker; 
reg speaker; 
reg[7:0] state; 
reg song_on; 
wire[6:0] in; 

reg[3:0] high,med,low; 
reg[13:0] divider,origin; 
reg[7:0] counter; 
reg out; 
wire carry; 

reg[20:0] i; 
parameter zero=8'b0000_0000, 
  one=8'b0000_0001, 
two=8'b0000_0010, 
three=8'b0000_0100, 
four=8'b0000_1000, 
five=8'b0001_0000, 
six=8'b0010_0000, 
seven=8'b0100_0000; 
initial  
begin 
song_on<=0; 
end 


always @(posedge song) 
begin 
song_on<=~song_on; 
end 

always @(posedge clk_6MHz) 
   
begin 
if(song_on) 
speaker<=out; 
else 
begin 
case(in) 
zero:begin 
speaker<=0; 
i<=0; 
end 
one:begin                //do 
if(i>=11451) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
two:begin //re 
if(i>=10204) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
three:begin //mi 
if(i>=9091) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
four:begin // fa 
if(i>=8596) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
five:begin //so 
if(i>=7653) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
six:begin //lo 
if(i>=6818) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
seven:begin //si 
if(i>=6073) 
begin 
speaker=!speaker; 
i<=0; 
end 
else 
i<=i+1; 
end 
default:begin 
speaker<=0; 
i<=0; 
end 
endcase 
end 
end 


assign carry=(divider==16383); 
always @(posedge clk_6MHz) 
begin  
if(carry)  
divider<=origin; 
else  
divider<=divider+1; 
end 
always @(posedge carry) 
begin 
out<=~out; //2 分频产生方波信号 
end 
always @(posedge clk_4Hz) 
begin 
case({high,med,low}) //分频比预置 
'b000000000011: origin<=7281; 
'b000000000101: origin<=8730; 
'b000000000110: origin<=9565; 
'b000000000111: origin<=10310; 
'b000000010000: origin<=10647; 
'b000000100000: origin<=11272; 
'b000000110000: origin<=11831; 
'b000001010000: origin<=12556; 
'b000001100000: origin<=12974; 
'b000100000000: origin<=13516; 
'b000000000000: origin<=16383; 
endcase 
end 
always @(posedge clk_4Hz) 
begin 
if(counter==63)  
counter<=0; //计时，以实现循环演奏 
else  
counter<=counter+1; 
case(counter) //记谱 
0: {high,med,low}<='b000000000011; //低音“3” 
1: {high,med,low}<='b000000000011; //持续4 个时钟节拍 
2: {high,med,low}<='b000000000011; 
3: {high,med,low}<='b000000000011; 
4: {high,med,low}<='b000000000101; //低音“5” 
5: {high,med,low}<='b000000000101; //发3 个时钟节拍 
6: {high,med,low}<='b000000000101; 
7: {high,med,low}<='b000000000110; //低音“6” 
8: {high,med,low}<='b000000010000; //中音“1” 
9: {high,med,low}<='b000000010000; //发3 个时钟节拍 
10: {high,med,low}<='b000000010000; 
11: {high,med,low}<='b000000100000; //中音“2” 
12: {high,med,low}<='b000000000110; //低音“6” 
13: {high,med,low}<='b000000010000; 
14: {high,med,low}<='b000000000101; 
15: {high,med,low}<='b000000000101; 
16: {high,med,low}<='b000001010000; //中音“5” 
17: {high,med,low}<='b000001010000; //发3 个时钟节拍 
18: {high,med,low}<='b000001010000; 
19: {high,med,low}<='b000100000000; //高音“1” 
20: {high,med,low}<='b000001100000; 
21: {high,med,low}<='b000001010000; 
22: {high,med,low}<='b000000110000; 
23: {high,med,low}<='b000001010000; 
24: {high,med,low}<='b000000100000; //中音“2” 
25: {high,med,low}<='b000000100000; //持续11 个时钟节拍 
26: {high,med,low}<='b000000100000; 
27: {high,med,low}<='b000000100000; 
28: {high,med,low}<='b000000100000; 
29: {high,med,low}<='b000000100000; 
30: {high,med,low}<='b000000100000; 
31: {high,med,low}<='b000000100000; 
32: {high,med,low}<='b000000100000; 
33: {high,med,low}<='b000000100000; 
34: {high,med,low}<='b000000100000; 
35: {high,med,low}<='b000000110000; //中音“3” 
36: {high,med,low}<='b000000000111; //低音“7” 
37: {high,med,low}<='b000000000111; 
38: {high,med,low}<='b000000000110; //低音“6” 
39: {high,med,low}<='b000000000110; 
40: {high,med,low}<='b000000000101; //低音“5” 
41: {high,med,low}<='b000000000101; 
42: {high,med,low}<='b000000000101; 
43: {high,med,low}<='b000000000110; //低音“6” 
44: {high,med,low}<='b000000010000; //中音“1” 
45: {high,med,low}<='b000000010000; 
46: {high,med,low}<='b000000100000; //中音“2” 
47: {high,med,low}<='b000000100000; 
48: {high,med,low}<='b000000000011; //低音“3” 
49: {high,med,low}<='b000000000011; 
50: {high,med,low}<='b000000010000; //中音“1” 
51: {high,med,low}<='b000000010000; 
52: {high,med,low}<='b000000000110; 
53: {high,med,low}<='b000000000101; //低音“5” 
54: {high,med,low}<='b000000000110; 
55: {high,med,low}<='b000000010000; //中音“1” 
56: {high,med,low}<='b000000000101; //低音“5” 
57: {high,med,low}<='b000000000101; //持续8 个时钟节拍 
58: {high,med,low}<='b000000000101; 
59: {high,med,low}<='b000000000101; 
60: {high,med,low}<='b000000000101; 
61: {high,med,low}<='b000000000101; 
62: {high,med,low}<='b000000000101; 
63: {high,med,low}<='b000000000101; 
endcase 
end 
endmodule 

二、电子钟 
module clock(work_state,clock_on,clk_6MHz,clk_4Hz,in_set,display_set,clk_1024Hz,up,down,out1,out2,out3,out4,out5,out6,out7,out8,speaker); 

input work_state,clk_1024Hz,up,down,display_set,clk_6MHz,in_set,clock_on,clk_4Hz; 
output out1,out2,out3,out4,out5,out6,out7,out8,speaker; 
wire[2:0] in_set; 
reg[3:0] out1,out2,out3,out4,out5,out6,out7,out8; 
reg[2:0] display_state; 
reg[7:0] hour,minute,second,year,month,day,day_max; 
reg[7:0] hour_set,minute_set,second_set,day_set,month_set,year_set,day_set_max; 
integer century=20; 
integer i=0; 
reg speaker; 

reg[7:0] clock_hour,clock_minute,clock_second; 

reg[3:0] high,med,low; 
reg[13:0] divider,origin; 
reg[7:0] counter; 
reg out; 
wire carry; 

//*****各初始值设置时对应的状态********// 
parameter state_yorh=3'b100,    //设置年或小时对应的按键状态 
  state_morm=3'b010, //设置月或分对应的按键状态 
  state_dors=3'b001; //设置日或秒对应的按键状态 


//***初始化时钟:08年08月08日00:00:00*****// 
initial 
begin 
year<=8; 
year_set<=8; 
month<=8; 
month_set<=8; 
day<=8; 
day_set<=8; 
hour<=0; 
minute<=0; 
second<=0; 
clock_hour<=0; 
clock_minute<=0; 
clock_second<=0; 
display_state<=0; 
end 


//******电子钟正常工作状态下/work_state等于0时,时钟处于工作状态*******// 
always @(posedge clk_1024Hz)         //频率选择1024HZ 
begin 
if(i>=1023) 
begin 
i<=0; 
if(work_state) 
begin 
second<=second_set; 
minute<=minute_set; 
hour<=hour_set; 
day<=day_set; 
month<=month_set; 
year<=year_set; 
end 
else 
begin 
if(second>=59) 
begin 
second<=0; 
if(minute>=59) 
begin 
minute<=0; 
if(hour>=23) 
begin 
hour<=0; 
if(day>=day_max) 
begin 
day<=1; 
if(month>=12) 
begin 
month<=1; 
if(year>=99) 
year<=0; 
else 
year<=year+1; 
end 
else 
month<=month+1; 
end 
else 
day<=day+1; 
end 
else 
hour<=hour+1; 
end 
  else 
minute<=minute+1; 
end 
else 
second<=second+1; 
end 
end 
else 
i<=i+1; 
end 

//******数码管显示状态设置*******// 
always @(posedge display_set) 
begin 
if(display_state>=2) 
display_state<=0; 
else 
display_state<=display_state+1; 
end 

//*闹钟模块设置，用clock_on控制闹钟，闹钟铃声播放时间为一分钟，可手动关闭闹钟**// 
always @(posedge clk_6MHz) 
begin  
if(clock_on) 
begin 
if(clock_hour==hour&&clock_minute==minute) 
speaker<=out; 
else speaker<=0; 
end 
else speaker<=0; 
end 

//*************设置时钟的初值*************************// 
/*用up来触发,当down=0时,一个上升沿触发来时加1,否则减1.***/ 
always @( posedge up) 
begin 
if(!work_state)       //时间处于正常工作状态时,使要设置的初始值保持同步 
begin 
    second_set<=second; 
minute_set<=minute; 
hour_set<=hour; 
day_set<=day; 
month_set<=month; 
year_set<=year; 
end 
else 
begin 
if(display_state==1)//当display_state==1时,则是设置年月日的初始值,否则是设置时间. 
begin 
if(down==0) 
begin 
case(in_set) 
state_yorh:begin 
if(year_set>=99) 
year_set<=0; 
else 
year_set<=year_set+1; 
end 
     state_morm:begin 
if(month_set>=12) 
month_set<=1; 
else 
month_set<=month_set+1; 
end 
     state_dors:begin 
if(day_set>=day_set_max) 
day_set<=1; 
else 
day_set<=day_set+1; 
end 
endcase 
end 
else  
begin 
case(in_set) 

state_yorh:begin 
if(year_set<=0) 
year_set<=99; 
else 
year_set<=year_set-1; 
end 
     state_morm:begin 
if(month_set<=1) 
month_set<=12; 
else 
month_set<=month_set-1; 
end 
     state_dors:begin 
if(day_set<=1) 
day_set<=day_set_max; 
else 
day_set<=day_set-1; 
end 

endcase 
end 
end 
else if(display_state==0) 
begin 
if(down==0) 
begin 
case(in_set) 

state_yorh:begin 
if(hour_set>=23) 
hour_set<=0; 
else 
hour_set<=hour_set+1; 
end 
     state_morm:begin 
if(minute_set>=59) 
minute_set<=0; 
else 
minute_set<=minute_set+1; 
end 
     state_dors:begin 
if(second_set>=59) 
second_set<=0; 
else 
second_set<=second_set+1; 
end 

endcase 
end 
else  
begin 
case(in_set) 

state_yorh:begin 
if(hour_set<=0) 
hour_set<=23; 
else 
hour_set<=hour_set-1; 
end 
     state_morm:begin 
if(minute_set<=0) 
minute_set<=59; 
else 
minute_set<=minute_set-1; 
end 
     state_dors:begin 
if(second_set<=0) 
second_set<=59; 
else 
second_set<=second_set-1; 
end 

endcase 
end 
end 
else if(display_state==2) 
begin 
if(down==0) 
begin 
case(in_set) 

state_yorh:begin 
if(clock_hour>=23) 
clock_hour<=0; 
else 
clock_hour<=clock_hour+1; 
end 
     state_morm:begin 
if(clock_minute>=59) 
clock_minute<=0; 
else 
clock_minute=clock_minute+1; 
end 
     state_dors:begin 
if(clock_second>=59) 
clock_second<=0; 
else 
clock_second<=clock_second+1; 
end 

endcase 
end 
else  
begin 
case(in_set) 

state_yorh:begin 
if(clock_hour<=0) 
clock_hour<=23; 
else 
clock_hour<=clock_hour-1; 
end 
     state_morm:begin 
if(clock_minute<=0) 
clock_minute<=59; 
else 
clock_minute<=clock_minute-1; 
end 
     state_dors:begin 
if(clock_second<=0) 
clock_second<=59; 
else 
clock_second<=clock_second-1; 
end 

endcase 
end 

end 
end 
end 


//**********本年度当前月的天数的计算**********// 
always @(day or day_set)//当日期变化时,则其所处月份的天数; 
begin 
if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)  
day_max<=31; 
else if(month==4||month==6||month==9||month==11)  
day_max<=30; 
else  
begin 
if(({century,year}%400==0)||(({century,year}%4==0)&&({century,year}%10!=0)))  
day_max<=29; 
else day_max<=28; 
end 

if(month_set==1||month_set==3||month_set==5||month_set==7||month_set==8||month_set==10||month_set==12)  
day_set_max<=31; 
else if(month_set==4||month_set==6||month_set==9||month_set==11)  
day_set_max<=30; 
else  
begin 
if(({century,year_set}%400==0)||(({century,year_set}%4==0)&&({century,year_set}%10!=0)))  
day_set_max<=29; 
else day_set_max<=28; 
end 
end 

//**********数码管显示模块,display_state=1时,显示年月日,否则显示时间//// 

always @(posedge clk_6MHz) 
begin 
if(!work_state) 
begin 
if(display_state==1) 
begin 
out8<=year%10; 
out7<=year/10; 
out6<=13; 
out5<=month%10; 
out4<=month/10; 
out3<=13; 
out2<=day%10; 
out1<=day/10; 
end 
else if(display_state==0) 
begin 
out8<=hour%10; 
out7<=hour/10; 
out6<=15; 
out5<=minute%10; 
out4<=minute/10; 
out3<=15; 
out2<=second%10; 
out1<=second/10; 
end 
else if(display_state==2) 
begin 
out8<=clock_hour%10; 
out7<=clock_hour/10; 
out6<=12; 
out5<=clock_minute%10; 
out4<=clock_minute/10; 
out3<=12; 
out2<=clock_second%10; 
out1<=clock_second/10; 
end 
end 
else 
begin 
if(display_state==1) 
begin 
out8<=year_set%10; 
out7<=year_set/10; 
out6<=13; 
out5<=month_set%10; 
out4<=month_set/10; 
out3<=13; 
out2<=day_set%10; 
out1<=day_set/10; 
end 
else if(display_state==0) 
begin 
out8<=hour_set%10; 
out7<=hour_set/10; 
out6<=15; 
out5<=minute_set%10; 
out4<=minute_set/10; 
out3<=15; 
out2<=second_set%10; 
out1<=second_set/10; 
end 
else if(display_state==2) 
begin 
out8<=clock_hour%10; 
out7<=clock_hour/10; 
out6<=12; 
out5<=clock_minute%10; 
out4<=clock_minute/10; 
out3<=12; 
out2<=clock_second%10; 
out1<=clock_second/10; 
end 
end 
end 

//*******用乐曲《梁祝》作为闹钟铃声*************// 

assign carry=(divider==16383); 
always @(posedge clk_6MHz) 
begin  
if(carry)  
divider<=origin; 
else  
divider<=divider+1; 
end 
always @(posedge carry) 
begin 
out<=~out; //2 分频产生方波信号 
end 
always @(posedge clk_4Hz) 
begin 
case({high,med,low}) //分频比预置 
'b000000000011: origin<=7281; 
'b000000000101: origin<=8730; 
'b000000000110: origin<=9565; 
'b000000000111: origin<=10310; 
'b000000010000: origin<=10647; 
'b000000100000: origin<=11272; 
'b000000110000: origin<=11831; 
'b000001010000: origin<=12556; 
'b000001100000: origin<=12974; 
'b000100000000: origin<=13516; 
'b000000000000: origin<=16383; 
endcase 
end 
always @(posedge clk_4Hz) 
begin 
if(counter==63)  
counter<=0; //计时，以实现循环演奏 
else  
counter<=counter+1; 
case(counter) //记谱 
0: {high,med,low}<='b000000000011; //低音“3” 
1: {high,med,low}<='b000000000011; //持续4 个时钟节拍 
2: {high,med,low}<='b000000000011; 
3: {high,med,low}<='b000000000011; 
4: {high,med,low}<='b000000000101; //低音“5” 
5: {high,med,low}<='b000000000101; //发3 个时钟节拍 
6: {high,med,low}<='b000000000101; 
7: {high,med,low}<='b000000000110; //低音“6” 
8: {high,med,low}<='b000000010000; //中音“1” 
9: {high,med,low}<='b000000010000; //发3 个时钟节拍 
10: {high,med,low}<='b000000010000; 
11: {high,med,low}<='b000000100000; //中音“2” 
12: {high,med,low}<='b000000000110; //低音“6” 
13: {high,med,low}<='b000000010000; 
14: {high,med,low}<='b000000000101; 
15: {high,med,low}<='b000000000101; 
16: {high,med,low}<='b000001010000; //中音“5” 
17: {high,med,low}<='b000001010000; //发3 个时钟节拍 
18: {high,med,low}<='b000001010000; 
19: {high,med,low}<='b000100000000; //高音“1” 
20: {high,med,low}<='b000001100000; 
21: {high,med,low}<='b000001010000; 
22: {high,med,low}<='b000000110000; 
23: {high,med,low}<='b000001010000; 
24: {high,med,low}<='b000000100000; //中音“2” 
25: {high,med,low}<='b000000100000; //持续11 个时钟节拍 
26: {high,med,low}<='b000000100000; 
27: {high,med,low}<='b000000100000; 
28: {high,med,low}<='b000000100000; 
29: {high,med,low}<='b000000100000; 
30: {high,med,low}<='b000000100000; 
31: {high,med,low}<='b000000100000; 
32: {high,med,low}<='b000000100000; 
33: {high,med,low}<='b000000100000; 
34: {high,med,low}<='b000000100000; 
35: {high,med,low}<='b000000110000; //中音“3” 
36: {high,med,low}<='b000000000111; //低音“7” 
37: {high,med,low}<='b000000000111; 
38: {high,med,low}<='b000000000110; //低音“6” 
39: {high,med,low}<='b000000000110; 
40: {high,med,low}<='b000000000101; //低音“5” 
41: {high,med,low}<='b000000000101; 
42: {high,med,low}<='b000000000101; 
43: {high,med,low}<='b000000000110; //低音“6” 
44: {high,med,low}<='b000000010000; //中音“1” 
45: {high,med,low}<='b000000010000; 
46: {high,med,low}<='b000000100000; //中音“2” 
47: {high,med,low}<='b000000100000; 
48: {high,med,low}<='b000000000011; //低音“3” 
49: {high,med,low}<='b000000000011; 
50: {high,med,low}<='b000000010000; //中音“1” 
51: {high,med,low}<='b000000010000; 
52: {high,med,low}<='b000000000110; 
53: {high,med,low}<='b000000000101; //低音“5” 
54: {high,med,low}<='b000000000110; 
55: {high,med,low}<='b000000010000; //中音“1” 
56: {high,med,low}<='b000000000101; //低音“5” 
57: {high,med,low}<='b000000000101; //持续8 个时钟节拍 
58: {high,med,low}<='b000000000101; 
59: {high,med,low}<='b000000000101; 
60: {high,med,low}<='b000000000101; 
61: {high,med,low}<='b000000000101; 
62: {high,med,low}<='b000000000101; 
63: {high,med,low}<='b000000000101; 
endcase 
end 

endmodule