jishu10.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;
use ieee.std_logic_unsigned.all;

entity jishu10 is
port(clk,clr,set:in std_logic;
               q:out std_logic_vector(3 downto 0));
end jishu10;

architecture rtl of jishu10 is
signal count:std_logic_vector(3 downto 0);
begin
  q(0)<=count(0);
  q(1)<=count(1);
  q(2)<=count(2);
  q(3)<=count(3);
 process(clk,clr)
   begin
    if(clr='1')then
      count<="0000";
    elsif(clk'event and clk='1')then
      if(set='1')then
        if(count="1001")then
           count<="0000";
        else count<=count+'1';
        end if;
      end if;
    end if;
 end process;
end rtl;