Download "Digital Filter Analyzer". (Zipped file, freeware) Here is Online Help This application makes you design FIR/IIR filters, analyze frequency response, check filtered output, quantize coefficients and generate VHDL codes. This may complete whole things for digital filters !? You can design FIR filters. LPF, HPF, BPF, BRF are available. You can design IIR filters, too. The coefficients are listed on the text window. You can also quantize those. And you can get VHDL code of the filter you designed!! Bit length of data and coefficients are reflected on the code. Download "Digital Filter Analyzer". (Zipped file, freeware) Upgraded on 10 September, 2004 (ver 2.6) See "Bug Information" for detail.