结合键盘，数码管等外设，利用51单片机实现一些确定的具有实用性的功能。
程序可实现功能如下：
1、　　时钟显示及调节：
2、　　日期显示及调节：
3、　　闹钟显示及设置：
当时钟与闹钟时间相同蜂鸣器响铃
4、　　秒表启停及清零：(Combined with keyboard, digital control and other peripherals, the use of 51 single-chip microcomputer to achieve some of the identified, practical function.
Procedures can be implemented as follows:
clock display and adjustment:
date display and regulation:
alarm clock display and settings:
The clock is the same as the alarm clock, and the buzzer rings
stopwatch start stop and cleared:)