电子信息科学与技术——毕业设计（论文）——倒计时实时时钟设计.doc

目 录 摘要 I ABSTRACT II 1 绪论 1 1.1 课题研究背景 1 1.2 课题研究意义 1 1.3 本文的结构 2 2 系统总体方案设计 2 2.1 时钟模块 3 2.2 显示模块 4 3 核心芯片介绍 5 3.1 DS1302简介 5 3.1.1 引脚功能和结构 5 3.1.2 DS1302的控制字节 6 3.1.3 数据输入/输出 6 3.1.4 DS1302的寄存器 7 3.1.5 对后备电源进行涓细电流充电 8 3.2 ATmega16介绍 9 3.2.1 ATmega16特点 9 3.2.2 ATmega16外部引脚与封装 9 4 系统硬件设计 10 4.1 应用系统结构 10 4.2 显示单元 11 4.2.1 数码管编码 11 4.2.2 系统显示面板部分 12 4.3 系统硬件的控制部分 13 5 系统软件设计 15 5.1 时钟芯片控制 16 5.2 倒计时信息计算 16 5.3 按键检测 17 6 系统调试 19 6.1 硬件调试 19 6.2 软件调试 21 6.3 软硬联调效果展示 22 7 总结 24 致 谢 25 参考文献 26 倒计时实时时钟设计 摘要 本文介绍了一个基于ATmega16单片机的倒计时实时时钟的设计，系统采用ATmega16作为主控核心，串行实时时钟芯片DS1302完成计时功能，采用7段数码管动态扫描显示。 文章主要分硬件设计和软件编程两个大方面。硬件设计主要包括中央处理单元电路、时钟电路。软件用C语言来实现，其系统主程序采用了状态机的分析设计思想，软件部分完成了对各个模块的控制、整合实倒计时实时时钟信息的显示键盘对时钟的设置时钟显示等功能。在Proteus和CodeVisionAVR软件上进行了仿真和调试实现了显示当前日期、时间以及剩余天数计算与显示，调整日期、时间达到了设计的要求和目的。 关键词：ATmega16单片机；DS1302；状态机；倒计时实时时钟A Design of Real-time Clock Countdown ABSTRACT This article describes a design of real-time clock countdown, this countdown based on ATmega16 microcontroller.ATmega16 as the main control core of the system, which using 7-segment digital tube display dynamic scanning, and serial real time clock chip DS1302 complete computing time function. Article focuses on two aspects, the one is hardware designing, the other is software programming. Hardware designing includes a central processing unit circuit and clock circuits. Software is written in C language, the main program of the system adopted the idea of state machine designing. The part of the software completes the control and integration of each module, and the realization of real-time countdown clock information display, and setting the clock by keyboard, and the clock display and so on. The simulation and debugging of the design are run on the software of the Proteus and CodeVisionAVR. The design realizes the functions such as displaying of current date and time, and the remaining number of days counting and displaying, and adjusting the date and time. This design meets