decl7s.vhd

一个简单的交通灯程序(包括验证,主程序,和译码程序),在ALTER DE2板上实现

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 <="1000000";
   WHEN "0001" => LED7S <="1111001";
   WHEN "0010" => LED7S <="0100100";
   WHEN "0011" => LED7S <="0110000";
   WHEN "0100" => LED7S <="0011001";
   WHEN "0101" => LED7S <="0010010";
   WHEN "0110" => LED7S <="0000010";
   WHEN "0111" => LED7S <="1111000";
   WHEN "1000" => LED7S <="0000000";
   WHEN "1001" => LED7S <="0010000";
when others => null;
end  case;
end process;
end;