1、　　利用8031作为主控制器组成一个电子跑表，采用4位LED显示器。

2、　　上电或RESET后能启动显示当前（时：分）：首次上电复位显示为0时0分，以后各次RESET均显示正确的当前时间。

3、　　当按下START键时，作为跑表使用，显示范围是：000.0-999.9秒，当按下STOP键时，跑表停止运行，并保留所停位置的时间显示不变。

4、　　利用H键作为时钟校正，即当按下H键时，显示的当前小时值以每秒加一的速度递增（24点即为0点），利用N键作为分校正，使用方法同H键，但60分钟即为0分。

-one, using 8031 as the main controller of an electronic stopwatch, using four LED display. 2, or RESET power can be activated after the current show (am : pm) : the first power-on reset showed At 0000 hours, after the meeting RESET show correct the present time. 3, press the START button, as the stopwatch use, display area is :000.0 - 999.9 seconds, when pressed STOP button, stopwatch stop running, and stop location to which the reservation is the time displayed unchanged. 4, H keys as the clock correction, that is, when? H bonds, shows the current value of an hour to a second increase at a rate (24 points shall be 12:00 a.m.), as the use of N bond is at, with the use of H keys, but 60 minutes shall be 0.