qiduanyima.vhd

本程序利用VHDL语言实现拔河游戏机的功能

library ieee;
use ieee.std_logic_1164.all;

entity qiduanyima is
 port(a,b,c,d:in std_logic;
            y:out std_logic_vector(6 downto 0));
end qiduanyima;

architecture one of qiduanyima is
signal data:std_logic_vector(3 downto 0);
begin
 data<=d&c&b&a;
  process(data)
  begin 
   case data is
    when"0000"=>y<="0111111";
    when"0001"=>y<="0000110";
    when"0010"=>y<="1011011";
    when"0011"=>y<="1001111";
    when"0100"=>y<="1100110";
    when"0101"=>y<="1101101";
    when"0110"=>y<="1111101";
    when"0111"=>y<="0100111";
    when"1000"=>y<="1111111";
    when"1001"=>y<="1101111";
    when others=>y<="1111111";
   end case;
  end process;
end one;