基于单片机的等精度频率计设计

中文摘要

频率的测量方法有：直接测量法,间接测量法,例如周期测频法、V-F转换法等。基于传统测频原理的频率计的测量精度将随被测信号频率的变化而降低针对传统测频原理的频率计的测量精度随被测信号频率的下降而降低，在实用中有较大的局限性，在对等精度测量原理和测量误差进行详尽介绍和分析的基础上，介绍了基于单片机的等精度频率计的系统构成和工作原理，以及系统的硬、软件设计。本文采用单片机MCS-51作为系统控制单元,辅以适当的软、硬件资源完成以单片机为核心的等精度频率计设计.通过单片机对同步门的控制,使被测信号和标准信号在闸门时间内同步测量,为了提高精度,将传统的测频功能转为测周期,采用多用期同步测量技术,实现了等精度测量.等精度频率测量方法消除了量化误差,可以在整个测试频段内保持高精度不变,其精度不会因被测信号频率的高低而发生变化。

关键词：周期测频法，单片机控制，软硬件结合。

Abstract

Frequency measurement method: direct measurement, indirect measurement, such as cycle frequency measurement method, V-F conversion method. Based on the traditional frequency measurement principle of the frequency of measurement accuracy will be tested with the frequency change and reduce the traditional frequency measurement principle of measurement accuracy with the measured signal frequency and reduce the decline, in the more practical limitations, in equal precision measurement principle and measurement error in detail introduction and Analysis on the basis, introduces the equal precision frequency meter based on microcontroller system composition and working principle of the system, and the hardware, software design. This paper adopts the single chip MCS-51 as the system control unit, supplemented by appropriate software, hardware resources in order to complete single-chip microcomputer as the core design of equal precision frequency meter. By means of single chip controlling the synchronous gate, so that the measured signal and standard signal in the gate time synchronization measurement, in order to improve the accuracy, the traditional frequency measurement function for measuring cycle, using multiple period synchronization measurement technology, realizes the equal precision measurement. The equal precision frequency measuring the quantization error can be eliminated, in the beta band to maintain the high accuracy constant, its precision is not due to the frequency of measured signal and change.

Key words : the cycle frequency measurement, single chip control, the combination of hardware and software.

目录

毕业设计（论文）任务书 (2)

中文摘要 (1)

Abstract (2)

一绪论 (8)

1.1课题研究的背景 (8)

1.2等精度频率计的测量原理 (5)

1.3 设计思路及技术指标 (7)

二 MCS-51单片机系统结构和原理 (9)

2.1 MCS-51单片机的简介 (9)

2.2 MCS-51单片机的结构 (9)

2.2.1 MCS-51单片机的结构特点 (9)

2.2.2 MCS—51单片机的结构框图 (10)

2.3 MCS—51单片机的外部引脚功能 (10)

2.3.1引脚功能描述 (11)

2.4 MCS-51单片机内部存储器 (13)

2.4.1 内部数据存储器（RAM） (16)

2.4.2内部程序存储器（ROM） (15)

2.5单片机输入输出端口 (19)

2.5.1并行I/O口 (19)

2.5.2串行I/O口 (19)

三硬件设计 (20)

3.1系统的整体框图 (23)