--乒乓球燈模塊
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity ball is
port(clk:in std_logic;--乒乓球燈前進(jìn)時(shí)鐘
	clr:in std_logic;--乒乓球燈清零
	way:in std_logic;--乒乓球燈前進(jìn)方向
	en:in std_logic;--乒乓球燈使能
	ballout:out std_logic_vector(7 downto 0));--乒乓球燈
end ball;
architecture ful of ball is
signal lamp:std_logic_vector(9 downto 0);
begin
process(clk,clr,en)
begin
if(clr='1') then--清零
	lamp<="1000000001";
elsif en='0' then
	elsif (clk'event and clk='1') then--使能允許，乒乓球燈前進(jìn)時(shí)鐘上升沿
		if(way='1') then--乒乓球燈右移
			lamp(9 downto 1)<=lamp(8 downto 0);
			lamp(0)<='0';
		else--乒乓球燈左移
			lamp(8 downto 0)<=lamp(9 downto 1);
			lamp(9)<='0';
		end if;
end if;
ballout<=lamp(8 downto 1);
end process;
end;