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Blackfin 561 with IIR Filters

Question asked by CristiS on Apr 17, 2018
Latest reply on May 14, 2018 by CristiS

Hi! I've inherited a program that works with a BF561 but I am trying to switch from using a FIR filter to the library functions for IIR filters and I have a few questions:

1) There are so many settings in Matlab to export coefficients, I'm trying to make sure I get them right. If I'm using the library function iir_fr32(), what settings do I need to consider when I export? Export as SOS, I believe. 32 bits? Or is it 31? What about overflow? and Matlab keeps outputting scaling values. How do I use those or negate those in my filter settings?

2) If I'm reading the program I inherited correctly, it looks like the current filter I'm using filters one sample at a time. Would it work with the iir_fr32() function to send one sample through at a time? Or does it need to be a whole waveform? Or can it be just part of a waveform at a time?

I'm pretty new at using filters so any details you can help with would be appreciated.