library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_unsigned.all;

entity Digital_Clock_Display is
port(
		clk1: in std_logic;
		enable: in std_logic;
		--reset: in std_logic;
		ones_second: out std_logic_vector (6 downto 0);
		ones_tens: out std_logic_vector (6 downto 0);
		minutes_second: out std_logic_vector (6 downto 0);
		minutes_tens: out std_logic_vector (6 downto 0);
		first_hour: out std_logic_vector (6 downto 0);
		second_hour: out std_logic_vector (6 downto 0)
		);
end Digital_Clock_Display;

architecture implementation of Digital_Clock_Display is
signal sec_ones, sec_tens, min_ones, min_tens, hour_ones, hour_tens: integer range 0 to 9:= 0;
signal count: integer:= 1;
signal clock: std_logic:= '0';
begin
 --clk generation.For 100 MHz clock this generates 1 Hz clock.
process(clk1)
	begin
		if(clk1'event and clk1='1' and enable = '1') then
			count <= count+1;
				if(count = 250000) then --50,000,000 Hz clock cycle
					clock <= not clock;
					count <=1;
				end if;
		end if;
end process;
	
process(clock)   --period of clk is 1 second.
	begin
		if(clock'event and clock='1') then
			sec_ones <= sec_ones+ 1;-- increment seconds after each 50MHz cycle
				if(sec_ones = 9) then
					sec_ones <=0;
					sec_tens <= sec_tens + 1; --once ones(second) place reaches 9, increment tens(seconds) place and reset ones place to 0
					if(sec_tens = 9) then
						sec_tens <= 0;
						min_ones <= min_ones +1;--once tens(second) place reaches 5, increment (ones)minutes place and reset tens place to 0
							if(min_ones = 9) then
							min_ones <=0;
							min_tens <= min_tens + 1; --once ones(minutes) place reaches 9, increment (tens)minutes place and reset ones place to 0
								if(min_tens = 5) then
								min_tens <= 0;
								hour_ones <= hour_ones +1; --once minute(tens) place reaches 5, increment (ones)hour place and reset tens place to 0
									if(hour_ones = 9) then
										hour_ones <= 0;
										hour_tens <= hour_tens +1;----once ones(hour) place reaches 9, increment tens(hour) place and reset ones place to 0
										if((hour_tens = 5) AND (hour_ones = 9)) then
											hour_tens <= 0;
											hour_ones <= 0;
										end if;
									end if;
								end if;
							end if;
					end if;
				end if;
			end if;
end process;

process(sec_ones)
	begin
		if sec_ones = 0 then ones_second <= "1000000"; -- displays 0
		elsif sec_ones = 1 then ones_second <= "1111001"; -- displays 1
		elsif sec_ones = 2 then ones_second <= "0100100"; -- displays 2
		elsif sec_ones = 3 then ones_second <= "0110000"; -- displays 3
		elsif sec_ones = 4 then ones_second <= "0011001"; -- displays 4
		elsif sec_ones = 5 then ones_second <= "0010010"; -- displays 5
		elsif sec_ones = 6 then ones_second <= "0000010"; -- displays 6
		elsif sec_ones = 7 then ones_second <= "1111000"; -- displays 7
		elsif sec_ones = 8 then ones_second <= "0000000"; -- displays 8
		elsif sec_ones = 9 then ones_second <= "0010000"; -- displays 9
		else ones_second <= "0111111"; --displays error
		end if;
end process;

process(sec_tens)
	begin
		if sec_tens = 0 then ones_tens <= "1000000"; -- displays 0
		elsif sec_tens = 1 then ones_tens <= "1111001"; -- displays 1
		elsif sec_tens = 2 then ones_tens <= "0100100"; -- displays 2
		elsif sec_tens = 3 then ones_tens <= "0110000"; -- displays 3
		elsif sec_tens = 4 then ones_tens <= "0011001"; -- displays 4
		elsif sec_tens = 5 then ones_tens <= "0010010"; -- displays 5
		elsif sec_tens = 6 then ones_tens <= "0000010"; -- displays 6
		elsif sec_tens = 7 then ones_tens <= "1111000"; -- displays 7
		elsif sec_tens = 8 then ones_tens <= "0000000"; -- displays 8
		elsif sec_tens = 9 then ones_tens <= "0010000"; -- displays 9
		else ones_tens <= "0111111"; --displays error
		end if;
end process;

process(min_ones)
	begin
		if min_ones = 0 then minutes_second <= "1000000"; -- displays 0
		elsif min_ones = 1 then minutes_second <= "1111001"; -- displays 1
		elsif min_ones = 2 then minutes_second <= "0100100"; -- displays 2
		elsif min_ones = 3 then minutes_second <= "0110000"; -- displays 3
		elsif min_ones = 4 then minutes_second <= "0011001"; -- displays 4
		elsif min_ones = 5 then minutes_second <= "0010010"; -- displays 5
		elsif min_ones = 6 then minutes_second <= "0000010"; -- displays 6
		elsif min_ones = 7 then minutes_second <= "1111000"; -- displays 7
		elsif min_ones = 8 then minutes_second <= "0000000"; -- displays 8
		elsif min_ones = 9 then minutes_second <= "0010000"; -- displays 9
		else minutes_second <= "0111111"; --displays error
		end if;
end process;

process(min_tens)
	begin
		if min_tens = 0 then minutes_tens <= "1000000"; -- displays 0
		elsif min_tens = 1 then minutes_tens <= "1111001"; -- displays 1
		elsif min_tens = 2 then minutes_tens <= "0100100"; -- displays 2
		elsif min_tens = 3 then minutes_tens <= "0110000"; -- displays 3
		elsif min_tens = 4 then minutes_tens <= "0011001"; -- displays 4
		elsif min_tens = 5 then minutes_tens <= "0010010"; -- displays 5
		else minutes_tens <= "0111111"; --displays error
		end if;
end process;

process(hour_ones)
	begin
		if hour_ones = 0 then first_hour <= "1000000"; -- displays 0
		elsif hour_ones = 1 then first_hour <= "1111001"; -- displays 1
		elsif hour_ones = 2 then first_hour <= "0100100"; -- displays 2
		elsif hour_ones = 3 then first_hour <= "0110000"; -- displays 3
		elsif hour_ones = 4 then first_hour <= "0011001"; -- displays 4
		elsif hour_ones = 5 then first_hour <= "0010010"; -- displays 5
		elsif hour_ones = 6 then first_hour <= "0000010"; -- displays 6
		elsif hour_ones = 7 then first_hour <= "1111000"; -- displays 7
		elsif hour_ones = 8 then first_hour <= "0000000"; -- displays 8
		elsif hour_ones = 9 then first_hour <= "0010000"; -- displays 9
		else first_hour <= "0111111"; --displays error
		end if;
end process;

process(hour_tens)
	begin
		if hour_tens = 0 then second_hour <= "1000000"; -- displays 0
		elsif hour_tens = 1 then second_hour <= "1111001"; -- displays 1
		elsif hour_tens = 2 then second_hour <= "0100100"; -- displays 2
		elsif hour_tens = 3 then second_hour <= "0110000"; -- displays 3
		elsif hour_tens = 4 then second_hour <= "0011001"; -- displays 4
		elsif hour_tens = 5 then second_hour <= "0010010"; -- displays 5
		else second_hour <= "0111111"; --displays error
		end if;
end process;

end implementation;