8-3编程器

cs375612

于 2010-10-08 10:12:00 发布

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CC 4.0 BY-SA版权

文章标签：编程 output vector input library

本文链接：https://blog.youkuaiyun.com/cs375612/article/details/6507718

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY encoder8_3 IS
PORT(RESET:IN STD_LOGIC;
  INPUT:IN STD_LOGIC_VECTOR(7 DOWNTO 0);
  OUTPUT:OUT STD_LOGIC_VECTOR(2 DOWNTO 0));
END encoder8_3;
ARCHITECTURE Behavioral OF encoder8_3 IS
BEGIN
PROCESS(RESET,INPUT)
BEGIN
IF(RESET='1') THEN
OUTPUT<="000";
ELSE
  CASE INPUT IS
   WHEN"00000001"=>OUTPUT<="000";
   WHEN"00000010"=>OUTPUT<="001";
   WHEN"00000100"=>OUTPUT<="010";
   WHEN"00001000"=>OUTPUT<="011";
   WHEN"00010000"=>OUTPUT<="100";
   WHEN"00100000"=>OUTPUT<="101";
   WHEN"01000000"=>OUTPUT<="110";
   WHEN"10000000"=>OUTPUT<="111";
   WHEN OTHERS=>OUTPUT<="000";
  END CASE;
END IF;
END PROCESS;
END Behavioral;