电子时钟设计毕业论文.doc

电子时钟设计
摘要: 时间是人类生活必不可少的重要元素,从古代的沙漏、十二天干地支,到后来的机械钟表以及当今的石英钟,都充分显现出了时间的重要性。随着社会的发展,人们对时间计量的精度要求越来越高,应用越来越广,功能要求越来越多。普通的机械钟表与半机械钟表对于当代人忙碌的生活显然早已不太适应,随着科技的进步,电子时钟应运而生,它不仅给人们生产生活带来了极大的方便,而且大大地扩展了时钟原先的功能。本课题研究的主要目的就是设计一个基于单片机定时器的时钟系统,它以AT89S52芯片为核心,结合显示驱动芯片74LS373、74LS138,控制键以及LED显示电路完成其显示、计数功能。由于单片机定时器是一种用数字电路技术实现时、分、秒计时的装置,与机械式时钟相比具有更高的准确性和直观性,且无机械装置,具有更更长的使用寿命,因此得到了广泛的使用。
关键字: 时间;电子时钟;AT89S52单片机;便捷
The Design of Electronic clock
Abstract: Time is an important element of the human’s life, from the ancient hourglass and the twelve heavenly stems and earthly branches, mechanical clocks and the quartz clock, it fully shows the importance of time. Along with the society's development, people’s requirement is getting higher and higher towards the accuracy of the time measurements, wide utilization and the strong function. General mechanical semi-mechanical watches and clocks already can’t fit in the modern people’s requirement. With the development of the technical, the electronic clock arises at the historic moment, it not only gave the enormous convenient to people but also expanded the clock’s original function accordingly. The aim of this research is to design a circuit timer's clock system which based on the monolithic integrated, it takes AT89S52 chip as the core, combine display drivers chip 74 LS373 and 74 LS138, control key and LED display circuit plete its display and count function. Due to the microcontroller is a smart device which uses the digital technology to show the hour, minutes and second, so it is much correct and intuitive than the regular mechanical clock and have a longer life that was warmly ed by the customers and widely used in the modern life.
Key words :Time ; Electronic clock; AT89S52 microcontroller; Convenient.
目录
1 绪论 1
课题的背景 1
课题的意义 1
国内外研究现状 2
论文构成以及章节安排 2
2 系统方案 3
系统方案选择 3
系统方案论证 3
系统结构框图 3
3 硬件系统设计 5
主控电路 5
AT89S52单片机的介绍 5
定时计数器的工作原理 7
中断 8
晶振特性 9
主控电路图 10