D_FLIP-FLOP ( Behavioral )

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

entity D_FF is

    Port ( clk, clr, pr,D :in STD_LOGIC ;

           Q ,Q_n : out  STD_LOGIC );

end D_FF;

architecture Behavioral of D_FF is

begin

process (clk, clr, pr,D)

begin

if pr = '0' then Q<='1';Q_n<='0';

elsif clr ='0' then Q<='0';Q_n<='1';

elsif clk='1' and clk'event then

      if D='0' then Q<='0';Q_n<='1';

       else Q<='1'; Q_n<='0';

      end if;

end if;

end process;

end Behavioral;