library IEEE; use IEEE.STD_LOGIC_1164.ALL; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; -- Uncomment the following lines to use the declarations that are -- provided for instantiating Xilinx primitive components. --library UNISIM; --use UNISIM.VComponents.all; entity dffen is Port ( reset : in std_logic; clk : in std_logic; en : in std_logic; din : in std_logic; qout : out std_logic); end dffen; architecture Behavioral of dffen is -- signals signal q : std_logic; begin qout <= q; process (reset, clk, en, din) begin if reset = '0' then q <= '0'; elsif (clk'event and clk = '1') then if en = '0' then q <= din; else q <= q; end if; end if; end process; end Behavioral;