基于PWM技术的可控频率触发器实现

范文编号:JD1165  范文字数:16237,页数:46  附任务书，开题报告，文献综述，外文翻译，中期检查

文档设计说明书（范文）中文摘要

 随着电子信息产业的不断发展，可调频率触发器在科技研究和实际应用中的作用日益重要。传统的频率触发器通常是用很多的逻辑电路和时序电路来实现的，这种电路一般运行缓慢，而且测量频率的范围比较小。考虑到上述问题，该文设计一个基于PWM技术的数字频率触发器。它可以产生方波和三角波，而且波形的频率和占空比可用程序控制改变。在单片机上加外围器件矩阵式键盘，通过键盘控制波形频率的增减以及波形的选择，并用LCD液晶显示器显示频率大小和占空比，也可通过上位机直接设置频率和占空比。该文从频率触发器的原理出发，介绍了基于单片机的数字频率触发器的设计方案，选择了实现系统得各种电路元器件，完成硬件并对硬件电路进行调试。

 关键词  P89LPC936单片机  PWM  频率计  LM8053液晶显示器  

文档设计说明书（范文）外文摘要

 Title      the controlled frequency trigger base on the pwm technology and aim to realize                                              
  ——The Hardware Design                                      

Abstract
Along with the development of the electronic information industry, Adjustable frequency triggers an increasingly important role in scientific research and practical applications. The traditional frequency flip-flop is usually a lot of logical circuit and the sequential circuits to fulfill.This circuit, general slowdown, And the measurement frequency range is relatively small. Taking into account the above-mentioned problems, This paper based on the design of PWM technology digital frequency trigger. It can produce square wave and triangle wave. And the frequency of the waveform and occupies emptiescompared available program control change. In the single and peripheral devices matrix keyboard, Through the keyboard control of the increase and decrease of the waveform and frequency wave of choice, And the LCD display shows the frequency size and duty cycle, Set frequency and duty cycle can also be directly through the PC. In this paper, the principle of frequency trigger. Introduces the design of microcontroller-based digital frequency trigger.Chosen to implement the system have a variety of circuit components Complete physical and cuit testing it.

 Keywords  P89LPC936 microcontroller  pwm  Frequency meter  LM8053 LCD monitor 

目  次

1  引言 1
1．1  概述 1
1．2  设计任务以及要求 1
2  方案论证 3
2．1  PWM脉冲波的产生设计的几种方案 3
2．2  软件语言 4
3  总体方案介绍 5
3．1  WM技术 5
4  硬件电路介绍 8
4．1  总体电路原理图 8
4．2  P89LPC933/934/935/936 Flash单片机 8
4．3  单片机时钟系统 10
4．4  捕获/比较单元（CCU） 10
4．5  UART 15
4．6  CD4069 反相器 16
4．7  主芯片系统 16
4．8  RS232接口 19
5  系统运行过程简介 21
5．1  总体及各个部分的程序流程图 21
6  调试 24
结论 25
致谢 26
参考文献 27
附录A:  源程序 28
图1：  原理图 41
表1：  元器件清单 43

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