ADLD_Digital_Clock

module clock(out,reset,clk,seg,enable,hours,stopwatch);
input reset,clk,stopwatch;//reset,clk and stopwatch is the input of digital clock.
output reg [7:0]out;//out is a 8 bit output,which is used for LED.
output reg [3:0]enable,seg;//4 bit enable and segment signal are used.
reg [25:0]count1,count2;//count1 and count2 is used for count the posedge of clock.
reg [3:0]sec0,sec1,min0,min1;//sec0,sec1,min0,min1 are 4 bit counters.
reg clk_1s,clk_count ;//clk_1s will goes high in every 1 second and clk_count is used for switching.
reg [3:0]counter;//4 bit counter is used.
output reg [4:0]hours;//5 bit binary output is used for hours.
always @(posedge clk)
begin
if(reset)
count1=26'd0;
else if
(count1 == 26'd25000000)//this always block is used for generating clock of 1 second.
            begin
            clk_1s = ~clk_1s;
count1 = 26'd0; end
else if(stopwatch==1'b1)//if stopwatch is high then our output will stop.
clk_1s=1'b0;
else
count1 = count1+26'd1;
end

always@(posedge clk)
begin
if(count2==26'd10000)//this always block is used for switching the 7 segment LED.
begin
clk_count=~clk_count;
count2<=26'd0;
end
else
count2<=count2+1;
end



always@(posedge clk_1s )
begin
if(reset==1'b1) begin //this always block works on 1 second of clock.
    sec0=0;
             sec1=0;
             min0=0;
             min1=0;  end
else if(sec0<9)//if LSB bit of second is less than 9 then it will increse.
      sec0=sec0+1;
else if(sec1<5) //if MSB bit of second is less than 5 then it will increse
begin          //and LSB bit of second will become 0.
      sec1=sec1+1;
      sec0=0;
end
else if(min0<9) //if LSB bit of minute is less than 9 then it will increse
begin          //and LSB bit of second will become 0.


min0=min0+1;  //and MSB bit of second will become 0.
sec0=0;
sec1=0;
end
else if(min1<5)//if MSB bit of minute is less than 5 then it will increse
begin         //and MSB bit of second will become 0.
min1=min1+1; //and LSB bit of second will become 0.
sec0=0;     //and LSB bit of minute will become 0.
sec1=0;
min0=0;
end
else if(min1==4'd5&&min0==4'd9&&sec0==4'd9&&sec1==4'd5)
begin     //if minute is 59 and second is 59 then it will work.
sec0=0;  //if all the above conditions are satisfied then
sec1=0; // all the minutes and seconds will become 0
min0=0;// and hours will incremented and give binary output.
min1=0;
hours=hours+5'd1;
end
else if(hours==5'd24)
begin
hours=5'b00000;//if hours is greater than 24 then
sec0=0;       //all the minutes,seconds and hours will start from 0.
sec1=0;
min0=0;
min1=0; end
end



always @(posedge clk_count)//this always block is used for enabling the LED
begin                 //and assigning the value of minute and second in seg
if(reset)            //and enabling the dot on 7 segment LED.
    counter=0;
else
counter=counter+1;
case(counter)
4'b0001 :
begin     enable=4'b1110;
           seg <= sec0;
           out[7]<=1;                              end
4'b0010 :
begin     enable=4'b1101;
          seg <= sec1;
                            out[7]<=1;           end
4'b0011 :
begin     enable=4'b1011;
          seg <= min0;
                            out[7]<=clk_1s;  end
4'b0100 :
begin    enable=4'b0111;
         seg <= min1;
         out[7]<=1;                              end
default : counter=4'b0000;
endcase
end

//this always block is used as BCD to 7 segment converter.
always@(seg)
begin
case(seg)//this case is working on seg.
                4'b0000 :out[6:0] = 7'b0000001;
             4'b0001 :out[6:0] = 7'b1001111;
             4'b0010 :out[6:0] = 7'b0010010;
             4'b0011 :out[6:0] = 7'b0000110;
             4'b0100 :out[6:0] = 7'b1001100;
             4'b0101 :out[6:0] = 7'b0100100;
             4'b0110 :out[6:0] = 7'b0100000;
             4'b0111 :out[6:0] = 7'b0001111;
             4'b1000 :out[6:0] = 7'b0000000;
             4'b1001 :out[6:0] = 7'b0000100;

endcase
end
endmodule