LED同时开启和关闭

大家好，我是Vittorio，我是FPGA和vhdl的初学者，我正在使用spartan3-e demoboard和digilent的Lcd。
我有这个问题，也许一些专家可以帮助我理解。
请参阅下面的代码如果输入引脚上的转换发生变化，我想驱动四个LED。
如果输入引脚为“1”，则如果输入引脚为“0”，则希望相继打开芯片1毫秒，并依次关闭所有LED。
我的问题是LED同时开启和关闭......这是什么交易？
先谢谢你。
图书馆IEEE;
使用IEEE.STD_LOGIC_1164.ALL;
使用IEEE.STD_LOGIC_ARITH.ALL;
使用IEEE.STD_LOGIC_UNSIGNED.ALL;
----如果实例化，则取消注释以下库声明
----本代码中的任何Xilinx原语。
- 图书馆UNISIM;
- 使用UNISIM.VComponents.all;
实体Powersequencer是
端口（VDDCHK：STD_LOGIC;
CLK：在STD_LOGIC中;
VDD：输入STD_LOGIC;
VDDIN：输入STD_LOGIC;
VH：inout STD_LOGIC;
COMn：inout STD_LOGIC）;
结束权力顺序;
建筑行为的力量序列是
开始
过程（CLK，VDDCHK）
开始
如果VDDCHK ='1'那么
VDD VDDIN VH COMn elsif VDDCHK ='0'然后
VDD VDDIN VH COMn结束if;
结束过程;
结束行为;



以下为原文

Hello All, i'm Vittorio and i'm a beginner in fpga and vhdl, i'm using spartan3-e demoboard with Lcd from digilent. i have this issue and maybe some expert can help me to understand. pls see the code below i would like to drive four LED if a contition on the input pin change. If the input pin is "1" a would like turn on chip in sequence by 1millisecond from eachother and turn off all led in sequence if the input pin is "0". my problem is the LED turns on and off simultanusly... what's the deal? thank you in advance.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity Powersequencer is
    Port ( VDDCHK : in  STD_LOGIC;
           CLK : in  STD_LOGIC;
           VDD : inout  STD_LOGIC;
           VDDIN : inout  STD_LOGIC;
           VH : inout  STD_LOGIC;
           COMn : inout  STD_LOGIC);
end Powersequencer;

architecture Behavioral of Powersequencer is

begin

process (CLK, VDDCHK)

begin

if VDDCHK='1' then
VDD <='1' after 100 ms;
VDDIN<='1' after 200 ms;
VH<='1' after 300 ms;
COMn<='1' after 400 ms;
elsif VDDCHK='0' then
VDD <='0' after 100 ms;
VDDIN<='0' after 300 ms;
VH<='0' after 200 ms;
COMn<='0' after 100 ms;
end if;

end process;


end Behavioral;