dff.vhd

VHDL子程序集,包括各种例程资料以及源码.

--*********************************
--*    D Filp Flop (COMPONENT     *
--*        Filename : DFF         *
--*********************************

library IEEE;
use IEEE.std_logic_1164.all;

entity DFF is
    port (
          D:     in STD_LOGIC;
          CLK:   in STD_LOGIC;
          RESET: in STD_LOGIC;
          Q:     out STD_LOGIC
         );
end DFF;

architecture DFF_arch of DFF is

begin
process (CLK,RESET)
begin
    if RESET = '1' then
       Q <= '0';
    elsif CLK'event and CLK = '1' then
       Q <= D;
    end if;
end process;    
 
end DFF_arch;