實驗五 碼制轉換器實驗

library ieee;  use ieee.std_logic_1164.all; use ieee.numeric_std.all;  entity docoder_3_to_8 is    port     (       a,b,c,g1,g2a,g2b: in std_logic;             y: out std_logic_vector(7 downto 0));  end entity;    architecture rtl of  docoder_3_to_8 is  signal indata:std_logic_vector(2 downto 0);  begin     indata<=c&b&a;process(indata,g1,g2a,g2b)isbeginif(g1='1'and g2a='0'and g2b='0')then case indata is     when "000"=>y<="11111110";      when "001"=>y<="11111101";     when "010"=>y<="11111011";       when "011"=>y<="11110111";     when "100"=>y<="11101111";      when "101"=>y<="11011101";       when "110"=>y<="10111101";     when "111"=>y<="01111101";when others=>y<="XXXXXXXX";end case;else  y<="11111111";end if;end process;end architecture rtl;