bcd7.vhd

数字秒表具有正及时倒计时功能包括一些设计要求和原资料

 LIBRARY  IEEE;
   USE  IEEE.STD_LOGIC_1164.ALL;
   USE  IEEE.STD_LOGIC_UNSIGNED.ALL;
   ENTITY  BCD7  IS
       PORT(BCD:IN  STD_LOGIC_VECTOR(3 DOWNTO 0);
          LED:OUT  STD_LOGIC_VECTOR(6 DOWNTO 0));
   END  BCD7;
   ARCHITECTURE  ART  OF  BCD7  IS
          BEGIN
          LED<= "1111110"WHEN  BCD="0000"ELSE
                "0110000"WHEN  BCD="0001"ELSE
                "1101101"WHEN  BCD="0010"ELSE
                "1111001"WHEN  BCD="0011"ELSE
                "0110011"WHEN  BCD="0100"ELSE
                "1011011"WHEN  BCD="0101"ELSE
                "1011111"WHEN  BCD="0110"ELSE
                "1110000"WHEN  BCD="0111"ELSE
                "1111111"WHEN  BCD="1000"ELSE
                "1111011"WHEN  BCD="1001"ELSE
                "0000000";
END  ART;