说明：  数字时钟设计 利用实验仪，完成数字时钟设计，能实现时间的调整、定时时间的设定，输出等功能。系统的功能选择由SB0、SB1、SB2、SB3 完成。其中SB0为时间校对，定时器调整功能键，按SB0 进入调整状态。按SB1键，依次进入时间时位校对、分位校对、秒位校对状态。不管是进入那种状态，按动SB2 皆可以使被调整位进行不进位增量加1 变化。各预置量设置完成后，系统将所有的设置存入RAM 中，按SB3 退出调整状态。上电后，系统自动进入计时状态，起始于00时00分00秒。定时时间到，二极管发亮。显示时间的格式为XX：XX：XX。
(Single Chip Microcomputer is widely used in Real-time Control, Intelligent Instrument, Instrumentation Communication and Domestic Appliance. It is adapted to lots of basic knowledge such as Computer Science, Electronics, and System Dynamics and so on. The Hardware Design this time is based on the 51 Single Chip Microcomputer bought on line. And it can control the display of HOUR, MINUTE and SECOND. The three can display on the 8 bits Nixie light .The LED attempts the 24-hour time measurement . If you could adjust the clock to certain time ,the LED lights will shine and also the alarm will ring. LED Display employ Dynamic Scan Display and the 12M-frequency crystal.)