FFT on a ADAU1701?
Is the ADAU1701 a suitable part for performing processing & analysis in the frequency domain?
Specifically, I need to do an FFT, spectral power density, and singular value decomposition functions on 24 bit data. The SigmaStudio software does not offer an FFT function, so I would need to build an FFT from "scratch" using the basic add, multiply and delay blocks. This seems like a bad idea--if the part was designed to do an FFT, it would be a canned function in SigmaStudio, right? Can a 1024 point FFT be implemented on the ADAU1701? If so, how much of the ADAU1701's resources would be eaten up by doing this?
HI Jennifer:
The 1701 is not the part you should be looking at. Please consider either the 1452 or the Sharc for these type of processing. I don't recommend you do a 1024 size FFT. This is too memory consumming specially if you need to do this with some type of overlap add scheme on your application.
Can you tell us more about your application?
Regards
Miguel
Hi Jennifer,
The ADAU1701 does not support block processing since it is a sample-by-sample processing machine.,
The ADAU1452 (or ADAU1451/ADAU1450) however, does support block processing and we include FFT and IFFT blocks with SigmaStudio, and has the MIPS and memory to support it.
JT
Sorry, I just saw Miguel's reply that maybe 1K FFT sizes might be too expensive on the ADAU1452 (depends on the number of channels to process?), but the block processing is there to support the FFT.
-JT
John & Miguel,
Thank you for the quick responses, I will take a look at the ADAU1452. I suspect that some of constraints for the design will need to be relaxed. [The application is a general research board that can do "pretty good" frequency analysis of 24 bit A/D samples with a sample rate of 48kHz. "Pretty good" has yet to be defined based on what's reasonable to accomplish in the alloted time frame.] The SigmaDSP line is attractive since it offers the integrated A/D and the nice GUI drag & drop interface for DSP newbies such as myself.
Do you have a feel for what the maximum number of FFT points that can be used in the 1452 is, if no other processing is done? You indicated that 1024 is not recommended, so would 512 be reasonable? Also, is there a rule of thumb as far as MIPS needed in relation to FFT size?
Thanks again,
Jennifer
Hi John,
On what version of Sigma Studio do these Frequency Domain function (FFT etc ) exist ? I don't see on 3.11 or 3.12Beta ?
Thanks
Neil P.
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