decode47.vhd

电子抢答器 系统复位后进行抢答．超前抢答显示犯规信号

library ieee;
use ieee.std_logic_1164.all;
entity decode47 is port
	(adr		:in std_logic_vector(3 downto 0);
	 decodeout	:out std_logic_vector(6 downto 0)
	);
end decode47;

architecture truthtable of decode47 is
begin
	process(adr)
		begin
				case adr is
					when "0000"=>decodeout<="1111110";
					when "0001"=>decodeout<="0110000";
					when "0010"=>decodeout<="1101101";
					when "0011"=>decodeout<="1111001";
					when "0100"=>decodeout<="0110011";
					when "0101"=>decodeout<="1011011";
					when "0110"=>decodeout<="1011111";
					when "0111"=>decodeout<="1110000";
					when "1000"=>decodeout<="1111111";
					when others=>decodeout<="1111011";
				end case;
	end process;
end truthtable;