基于TMS320F2812的数字频率计  

A Frequency Counter Based on TMS320F2812

作　　者：方敏[1] 侯其立[1] 李苗[1] 张巧云[1] 徐科军[1] 

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽合肥230009

出　　处：《实验室研究与探索》2009年第5期37-40,共4页Research and Exploration In Laboratory

基　　金：合肥工业大学2008年大学生创新性实验计划项目;安徽省高等学校省级教学研究项目;合肥工业大学教学改革研究项目

摘　　要：采用多周期测量原理,即用标准频率信号填充整数个周期的被测信号,从而消除了被测信号±1的计数误差,其测量精度仅与门控时间和标准频率有关,克服传统的直接测频或者直接测周法均不能全面满足高精度要求的缺陷。选用TMS320F2812型号的DSP芯片作为核心处理单元,结合其高精时钟和快速运算的优点,利用其内部的事件管理器:捕获单元,定时/计数单元,比较单元,脉宽调制电路PWM,实现高精度的频率测量,并实现了脉宽和占空比的测量。The measurement principle of multi-period signal was adopted in the design. It uses a standard frequency signal to fill the measured signal of integral number period in order to eliminate ＋ 1 counting error. Its measurement accuracy only relies on the gate control time and the standard frequency. This method overcomes the limitation of traditional direct measuring period or measuring frequency methods, and can satisfy the requirement of high accuracy. A DSP chip （TMS320F2812） is selected as the core-processing unit because it possesses the high-precision clock and can perform the fast calculation. Its event-managers including the capture unit, timer/counter unit, comparator unit and pulse-width modulation circuit （PWM） are utilized effectively to realize the high-precision frequency measurement, the pulse-width measurement and the occupancy ratio measurement.

关 键 词：高精度频率测量 脉宽 占空比 多周期测量原理 数字信号处理器 

分 类 号：TB939[一般工业技术—计量学]