emergency.vhd

vhdl语言编写的交通灯程序

library ieee;
use ieee.std_logic_1164.all;

entity Emergency is 
	port(
		BTN_in:in std_logic;
		BTN_out:out std_logic
		);
end Emergency;

architecture Emergency_arc of Emergency is
begin
	process(BTN_in)
	variable temp: std_logic;
	begin
		if BTN_in'event and BTN_in='1' then
			temp:= not temp;
		end if;
		BTN_out<=temp;
	end process;
end;