用TMS320C25实现IIR数字滤波器

Implementation of IIR Digital Filter with TMS320C25

本文介绍了用TMS320C25单片数字信号处理器实现无限冲击响应(IIR)数字滤波器的实时滤波技术,阐述了以2阶基本节为子节的级联型结构IIR滤波器的实现原理.按照实时处理原则,重点放在如何减少处理时间和所需的数据存储单元,采用TMS320C25内部定时中断来控制采样速率.以实现级联型4阶IIR椭圆数字低通滤波器为例,给出了TMS320C25汇编语言源程序,并给出了所实现的滤波器频率响应.

In this paper, a technique for implementing Infinite Impulse Response (IIR) digital filter with TMS320C25 is introduced. A principle for implementing cascade structure IIR digital filter with second-order subsections is described. According to the rule of real time processing, emphasis is on minimizing both the execution time and the number of data memory location required. Using the internal timing interruption of TMS320C25, the specified sampling rate is controlcd. With an example of implementation of cascade structure fourth-order IIR elliptic lowpass filter, the TMS320C25 assembly language source code is presented, and the frequency response of the implemented filter is given.