摘 要
近年来随着计算机在社会领域的渗透和大规模集成电路的发展，单片机的应用正在不断地走向深入，由于它具有功能强，体积小，功耗低，价格便宜，工作可靠，使用方便等特点，因此特别适合于与控制有关的系统，越来越广泛地应用于自动控制，智能化仪器，仪表，数据采集，军工产品以及家用电器等各个领域，单片机往往是作为一个核心部件来使用，在根据具体硬件结构，以及针对具体应用对象特点的软件结合，以作完善。单片机技术起着不可忽视的作用并且在智能控制领域有着举足轻重的地位。本设计就是利用Atmel 公司生产的单片机AT89S52芯片和AT24C02芯片（存储芯片），以及利用DS1302用作时钟芯片（具有实时显示当前时间，按设定时间用蜂鸣器报时，能修改当前时钟（闹钟）等功能）。在以单片机为核心的基础上加上其外围设备实现的小的系统——自动打铃系统。网上购书电子商务系统
abstract
In recent years, with the computer in the social sector infiltration and large scale integrated circuit of development, the application of SCM is continuously to the deepening, because it has a strong function, small volume, low power consumption, low price and reliable work, use convenient wait for a characteristic, therefore particularly suitable for related control and system, widely used in automatic control, intelligent instruments, meters, data acquisition, military products and home appliances and other fields, microcontroller is often as a core component to use, according to the specific hardware structure, and the view of the specific application object characteristics of software combines, make the perfect. Microcontroller technology plays an important role in the field of intelligent control and play a significant role. This design is using Atmel company produces the monolithic integrated circuit AT89S52 chips and AT24C02 chip (memory chip), and the use of DS1302 used for clock chip (with real-time display the current time, according to the set time with buzzer hour, can modify the current alarm clock () function). In based on singlechip basis plus its peripherals to realize the small system - automatic ringing the bell system.