通过P1.0端口以1HZ的频率输出信号，使用该信号点亮一个LED指示灯，

并将信号接入到INT1，统计中断的次数。

将中断的次数通过两个七段数码管采用十进制显示出来。当超过99次后，清零并 重新计数。-1HZ by P1.0 port to the frequency output signal, using the signal light an LED indicator, and signal access to the INT1, statistics the number of interrupts. The number of times will break through the adoption of the decimal two seven-segment digital tube display. When more than 99 times, cleared and re-count.