Polyphase Filtering in SigmaStudio

Hello logoho,

Unfortunately it is not possible to do multi-rate processing in this core. That is a good question regarding the polyphase filtering. I cannot help you with that but perhaps someone else on the forum might chime in.

Dave T

Hi Logoho:

Making a polyphase filtering will be possible for the 144x but has not being requested in the past. Do you have some documentation on the type of filtering you are specifically looking for? I can add it to a "todo" list or you may want to contract a 3rd party of this is more urgent.

My guess is that using a long FIR filter by itself is not possible because of the number of tabs you need?

FYI, the ADAU145x is able to execute 4 tabs in a cycle, making it ideal for long FIR filter applications.

Please comment.

Miguel

Hello mmmike,

thank you for your answer.

Yes, we need long FIR filters for linear phase subwoofer. But at the same time, also not polyphase filters should be computed by the DSP. Is this possible at all?

The possibility of making polyphase filters on the ADAU1442 would be very beneficial for us, since we need it because of its number of I2S connections. On the other side, it is not that urgend for us. What does that mean, how long would it take for your unit to implpement such a block?

Best regards,

logoho

p.s.: Here is a very good link how polyphase filters work. The coefficient will be calculated by MATLAB

http://www.ee.ic.ac.uk/hp/staff/dmb/courses/DSPDF/01200_Polyphase.pdf