-- 延遲，起時鐘同步作用。因為HELLO模塊有時鐘同步，所以送出的列值比送到
--端口上的列選擇信號玩一個時鐘周期。此模塊延時使HELLO模塊與tingche模塊同步。
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity delay is
	port(
		clk: in std_logic;
		a  : in std_logic_vector(2 downto 0);
		q  : out std_logic_vector(2 downto 0)
		);
end delay;

architecture delay of delay is
	begin
		process(clk)
		begin
			if clk'event and clk='1' then
				q<=a;
			end if;
		end process;
end delay;