文档介绍：毕业设计（论文）
题基于单片机的智能
电子计数器的设计
学 院：电信学院
专 业：电子科学与技术
学生姓名：
指导教师：
数字频率计是电子测量领域中最常见的测量仪器之一。它可以测量方波和正弦 波的频率、周期和脉冲宽度等时间参数。
本设计是由单片机控制的数字频率计设计。本文在讨论频率测量的常用方法与 原理的基础上，阐述了等精度测频系统的设计。系统包括稳压电源电路、信号放大 整形电路、测频电路、单片机电路模块、标准频率信号源、键盘模块、数码显示模 块等。采用软硬件结合的方法，频率、周期、脉宽和占空比的计算由单片机89C51 完成，外围电路其数字电路部分使用了 CPLD,并采用VHDL语言进行设计描述，其 输入通道由模拟电路来实现。
系统将单片机89C51的控制灵活性及CPLD芯片的现场可编程性相结合，不但大 大缩短了开发研制周期，而且使本系统具有结构紧凑、体积小、可靠性高、测频范 围宽、精度高等优点。
关键词：频率计单片机CPLD等精度
Abstract
Digital cymometer is one of the most common instruments of electronic measurement. It can measure time parameters such as the square wave and the sine wave frequency, cycle and pulse width, and so on.
The design is the digital cymometer based on the signal chip computer control. Based on the discussion of the commonly used method of measuring frequency and on the basis of principle, it describes the design of frequency measurement system with the same accuracy including the power supply system circuit, signal amplification plastic circuit, measuring frequency circuits, MCU circuit module, the standard frequency signal source, keyboard module, the digital display module, and so on. It takes the method of combination of hardware and software: frequency, period, pulse width and room-occupying ratio of calculation completed by the MCU 89C51, the external circuit part of its digital circuits used with the CPLD, input channels from analog circuits to achieve, and use of VHDL design Description. The system combines the control flexibility of 89C51 with programmable performance of CPLD, so not only can it shorten the period of the development and research but also has the advantages of compact structure little volume, high reliability, wide scope and high precision.
Key Words: cymometer; signal chip computer; CPLD; equal precision
目录
摘要 I
Abstract I
第一章引言 1
1
1
1
2
. 1 基本扌旨标 2
2
第二章系统硬件设计 1
1频率测量的方法的研究 1
2. 1. 1数字化直接测量频率的原理 1
2.