摘要：在日常生活和工作中，我们常常用到计时控制，如扩印过程中的曝光计时等。早期常用的一些时间控制单元都使用模拟电路设计制作的，其计时准确性和重复精度都不是很理想，现在基本上都是基于数字技术的新一代产品，随着单片机性能价格比的不断提高，新一代产品的应用也越来越广泛，大可构成复杂的工业过程控制系统，完成复杂的控制功能。小则可以用于家电控制，甚至可以用于儿童电子玩具。它功能强大，体积小，质量轻，灵活好用，配以适当的接口芯片，可以构造各种各样、功能各异的微电子产品。数字电子钟的设计方法有多种，例如，可用中小规模集成电路组成电子钟，也可以利用专用的电子钟芯片配以显示电路及其所需要的外围电路组成电子钟：还可以利用单片机来实现电子钟等等。这些方法都各有特点，其中，利用单片机实现的电子钟具有编程灵活，便于电子钟功能的扩充，精确度高等。

关键词：单片机、数字时钟、程序设计

Abstract：In daily life and work, we often used for timing control, such as Print process, such as exposure time to time. Early common control unit for some time to use the analog circuit design, and its timing accuracy and repeatability are not very satisfactory, and now are basically a new generation of digital technology-based products, with the constant cost-effective single-chip increase the application of a new generation of products has become increasingly widespread, they could constitute a complex industrial process control system, the completion of complex control functions. Small appliances can be used to control, or even electronic toys for children. It is powerful, small size, light weight, flexible and easy to use, with appropriate interface chip, can construct a wide range, functions of different micro-electronics products. The design of digital electronic clock a number of means, for example, can be used integrated circuits composed of small and medium-sized electronic bell, can also use a dedicated chip with an electronic clock display circuit and its peripheral circuits needed for the composition of electronic bell: can also use a single machine to achieve the electronic bell and so on. These methods have different characteristics, which, using an electronic bell Singlechip with programming flexibility, ease of electronic bell function of the expansion of higher accuracy.

Key words: single-chip, digital clock, program design