基于FPGA的CIC滤波器的设计

Design of CIC Filter Based on FPGA

CIC(cascade integrator comb,CIC)滤波器是一种结构简单、规整,占用存储量小的滤波器,不需要乘法器,因此占用资源少、实现简单且速度高,是高分解速率滤波器的一种非常有效的结构,在高速抽取或插值系统中是非常有效的单元。介绍了一般CIC滤波器的结构,展示了组成CIC滤波器的2个基本单元,通过其传递函数分析CIC滤波器的本质意义;讨论了应用Hogenaur"剪除"理论解决CIC输出端产生的非运行时间溢出问题以及CIC滤波器在FPGA上的实现方法。

CIC （cascade integrator comb, CIC） filter was one kind of filter which had simple, neat structure, took few reserves and did not need the multiplier. Therefore, it took few resources, implemented simply and had higher speed. In the high speed extraction or interpolation system, this filter was an extremely effective unit and the one kind of extremely effective structures of high decomposition speed filter. The general structure of CIC filter was introduced and the 2 basic units of CIC filter were demonstrated and the essential significance of CIC filter was analyzed through its transfer function; Using Hogenaur ＂extermination＂ theory to solve the non-running time overflow problem produced at output point. The realization method of CIC filter on FPGA was discussed.