LabVIEW Embedded
Blackfin real-time FFT
Hello,
I have a Blackfin BF537 ez-kit for implementing FIR filters. At first I tried the BF specific FIR filter and
managed to run it real-time with 300 something taps. I then thought I might be able to improve this number by
doing an overlap-add/save(multiplication in freq domain) implementation with an FFT and it all works fine BUT I
can't run it real-time. I made a simple FFT->IFFT(without any filtering in between) and measured the time it takes as seen below.
(I did some testing in MATLAB with standard FIR and overlap-add method and the overlap-add really improved
performance even for smaller buffers.)
Im running the application as follows:
At a buffer size of 512 each iteration takes 17.45 ms. Changing the buffer size doesn't improve this. For a real
-time application this has to be done in about 10.7ms at a sampling frequency of 48kHz.
Am I doing something wrong or is it not possible to implement a real-time FFT @ 48kHz on a BF537?
If it is possible, how do I do it?
If anyone has any experience of this PLEASE let me know, Im in dire need of information regarding this!
/ Anders
