shifterin.vhd

来自「用于视频运动图像编码的HUFFMAN编码」· VHDL 代码 · 共 40 行

library ieee;
	use ieee.std_logic_1164.all;
	use ieee.std_logic_unsigned.all;
	use ieee.std_logic_arith.all;
	
	
entity SHIFTER is
	
	port(	CLK:	in 	std_logic;
		RESET,LOAD:in std_logic;
		DIN:	in 	std_logic;
		DOUT:	out 	std_logic_vector(15 downto 0)	);
end SHIFTER;

architecture BEHAVIORAL of SHIFTER is
	signal Q:std_logic_vector(15 downto 0);
	
begin
	DOUT<=Q;
	BEHAVIOR: process(RESET,CLK)
	begin
		if RESET= '0' then
			Q<="0000000000000000";
		elsif CLK'event and CLK='1' then
			if LOAD='1' then
				for INDEX IN 15 downto 1 loop
					Q(INDEX)<=Q(INDEX-1);
				end loop;
				Q(0)<=DIN;
			else 
			end if;
		end if;
	
	end process BEHAVIOR;
	
end BEHAVIORAL;