Finite/Infinite Impulse Response Filter Generator

Explanation

This tool generates a Transposed Direct Form implementation of a Finite Impulse Response (FIR) filter, or an Infinite Impulse Response (IIR) filter, from a standard difference equation. The multiplier blocks within the design are generated from the Spiral Multiplier Block Generator. An FIR can be generated by simply setting a_0 to one and all other a_k constants to zero. The values of the b_k constants form the notches of the FIR. In the Transposed Direct Form I implementation, the IIR is generated from two separate FIR filters, connected by an adder. In the Transposed Direct Form II implementation, the FIR filter tool is not used at all, and the two multiplier block outputs are taken directly through adders and input into the flip flop array.

Standard Difference Equation

Transposed Direct Form
Finite Impulse Response Filter


Transposed Direct Form I Infinite Impulse Response Filter	Transposed Direct Form II Infinite Impulse Response Filter

Generator

Input:	Two lists of integer or fixed-point constants: a_0, ..., a_n-1 and b_0, ..., b_n-1
Output:	FIR/IIR Verilog code. The only operations used in the generated multiply blocks are additions, subtractions, shifts and negations.

Benchmarks

Reference

The filter generator uses the following paper work as core routine.

Yevgen Voronenko and Markus Püschel
Multiplierless Multiple Constant Multiplication
ACM Transactions on Algorithms, Vol. 3, No. 2, 2007

Copyrights to many of the above papers are held by the publishers. The attached PDF files are preprints. It is understood that all persons copying this information will adhere to the terms and constraints invoked by each author's copyright. These works may not be reposted without the explicit permission of the copyright holder. Some links to papers above connect to IEEE Xplore with permission from IEEE, and viewers must follow all of IEEE's copyright policies.

Software Download

Our software is available under GNU GPL license (a commercial license can be obtained on request): firgen.tgz (30 KB),

Note that the software needs the Spiral Multiplier block generator as subroutine.

Contact: help at spiral dot net