dff.txt

用vhdl编写的D触发器

library ieee;
use ieee.std_logic_1164.all;
entity dff is
port(d,clk:in std_logic;
      q    :out std_logic);
end;
architecture behavior of dff is
 begin
  process (clk)
   begin
    if(clk'event and clk='1') then q<=d;
   end if;
 end process;
end behavior;