主程序实现：1.时分秒显示

2.定时输出判断功能

中断程序功能：1.年月日显示

2.时间单元进位

3.时间设定时

4.调整时间设定时

按键切换：实现系统功能选择-Main program to achieve: 1. At 2 minutes and seconds display. From time to time determine the function of the output interruption program features: 1. 2 day of show. Time binary unit 3. Time settings 4. To adjust the time setting button switch: the realization of system options