old_decl7s.vhd

计数器和译码器的程序

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY DECL7S IS
 PORT (A: IN STD_LOGIC_VECTOR(3 DOWNTO 0);
  LED7S :OUT STD_LOGIC_VECTOR(6 DOWNTO 0));
END;
ARCHITECTURE one OF DECL7S IS
BEGIN
  PROCESS(A)
 BEGIN
 CASE A IS
   WHEN "0000"=>LED7S<="0111111";
   WHEN "0001"=>LED7S<="0000110";
   WHEN "0010"=>LED7S<="1011011";
   WHEN "0011"=>LED7S<="1001111";
   WHEN "0100"=>LED7S<="1100110";
   WHEN "0101"=>LED7S<="1101101";
   WHEN "0110"=>LED7S<="1111101";
   WHEN "0111"=>LED7S<="0000111";
   WHEN "1000"=>LED7S<="1111111";
   WHEN "1001"=>LED7S<="1101111";
   WHEN "1010"=>LED7S<="1110111";
   WHEN "1011"=>LED7S<="1111100";
   WHEN "1100"=>LED7S<="0111001";
   WHEN "1101"=>LED7S<="1011110";
   WHEN "1110"=>LED7S<="1111001";
   WHEN "1111"=>LED7S<="1110001";
   WHEN OTHERS => NULL;
   END CASE;
 END PROCESS;
END;