binary_to_gray.vhd

将二进制数转化为格备码

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library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity binary_to_gray is
	port(
		binary_code: in std_logic_vector(3 downto 0);
		gray_code: out std_logic_vector(3 downto 0));
end entity;

architecture behavior of binary_to_gray is

	signal code: std_logic_vector(3 downto 0);
	
begin
	process(binary_code)
	begin
		code(3) <= binary_code(3);
		code(2) <= binary_code(2) xor binary_code(3);
		code(1) <= binary_code(1) xor binary_code(2);
		code(0) <= binary_code(0) xor binary_code(1);
	end process;
	
	gray_code <= code;
end architecture;