LIBRARY IEEE;		--定義消抖電路
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY xiaodou IS 
	PORT(shuru,CP:IN STD_LOGIC; 	shuchu:OUT STD_LOGIC);--B為時鐘信號
END xiaodou;
ARCHITECTURE xiaodou_arc OF xiaodou IS 
	COMPONENT D_FF IS 
		PORT(A,B:IN STD_LOGIC; 	C,D:OUT STD_LOGIC);
	END COMPONENT;
	SIGNAL T1,T2,T3,T4,T5,T6:STD_LOGIC;
	signal q1,q2,temp,timetick:std_logic;
	signal counter:integer range 0 to 5000;
	
	BEGIN

fenpin:process(cp)
begin
	if cp'event and cp='1' then
		if counter=5000 then
			counter<=0;timetick<=not timetick;
		else counter<=counter+1;
		end if;
	end if;
end process fenpin;

		T2<=NOT (shuru AND T1);
		T1<=NOT (T2 AND T3);
		U2:D_FF   PORT MAP(T2,timetick,T4,T3);--CP為時鐘信號，T4為Q1
		U3:D_FF   PORT MAP(T4,timetick,T6,T5);--T6為Q2，T5為Q2非
		temp<=T4 AND T5;

weifen:process(timetick)
begin
	if timetick'event and timetick='1' then
		q1<=temp;
		q2<=q1;
	end if;
	shuchu<=q1 and not q2;
end process weifen;

END xiaodou_arc;