基于单片机的频率特性测试仪设计大学学位论文.doc

基于单片机的频率特性测试仪 摘 要 在电子技术，频率是最基本参数之一，并且与多电参量的测量方案、测量结果都有密切关系，因频率的测量就显得更为重要。包括信号输入、信号放大、信号选择、时钟提供、数据显示等功能模块为实现智能化的计数测频，实现一个宽领域、高精度的频率计,有效的方法是将单片机用于频率计的设计当中。本介绍以51单片机作为核心器件。由于本设计采用了模块化的设计方法，提高测量频率的范围。测量；频率计；单片机；汇编 FREQUENCY CHARATERISTIC TEST INSTRUMENT BASED ON MCU ABSTRAC Among electronic technology, frequency is one of the most basic parameters,and result of measuring have a very close relation to a lot of electric parameters, so the measurement of frequency seems even more important. Frequency counter can take the system with pure hardware circuitry. It includes the signal input, signal amplification, signal selection, the clock provides the data display modules. In order to realize the counting of intellectualityexamines frequently, realize a wide-range, high-accuracy cymometer, an effective method is to use one-chip computer for the design of the cymometer. Thissubject recommends regarding 51 Single-Chip computer as the key device, include signal input, signalamplify, signal choose, clock offer, data person who reveal function digital design method of cymometer of module still in addition.The hardware circuit of the cymometer is drawing with Protel mapping software,the one-chip computer control procedure of the software part, wrote the assembler language. Because originally design the design method to adopt module, improve the range of measuring frequency. And the drawing of this design,including hardware and software programming Key words:? Measurement; Cymometer; Single-Chip computer; Compilation 目 录 1 引言 1 1.1 数字频率计的发展和意义 1 1.2 数字频率国内外的发展形势 2 2 系统总体设计 3 2.1 系统设计要求 3 2.2 测频方法 3 2.3 系统设计思路 3 2.4 系统设计框图 4 3 系统硬件设计 5 3.1 单片机模块 5 3.1.1 AT89C52介绍 5 3.1.2 单片机引脚分配 6 3.1.3 复位电路 6 3.1.4 定时/计数器 6 3.2 放大整形模块 8 3.2.1 与非门74LS00 8 3.2.2 放大整形模块原理图 8 3.3 分频模块 9 3.3.1 分频器74LS161芯片 9 3.3.2 多路选择器74LS151芯片 10 3.3.3 分频模块原理图 12 3.4 显示电路 12 3.4.1 频率数值显示电路 12 3.4.2 频率数值单位显示电路 13 4 系统软件设计 15 4.1 开始 15 4.2 初始化模块 16 4.3 频率测量模块和量程自动切换模块 16 4.4 显示模块 17 4.5 延时模