ARM + DSP managing interrupts during FFT calculations.

Other Parts Discussed in Thread: OMAPL138

Dear Sirs,

I'm using an OMAPL138 processor to perform FFT calculations during sampling from an ADC via SPI.

I read that FFT from DSPLIB c647 is not interruptible: for me is a problem, because the fft takes approx. 20 us to elaborate 1024 pts, and in the meanwhile I would like to take samples from an ADC via SPI, managing interrupts and chip select.

For example, if I sample at 1MHz, I've got one interrupt every 1 us, and FFT is forced to fail by these interrupts.

Now, I'm arguing if it's possible to manage these interrupts with the ARM, write the samples to the DSP memory, then send a message to the DSP and perform the FFT. The DSP writes results on an output buffer, then ARM reads and do the other stuffs.

Do you think that ARM interrupts can disturb the fft on the DSP side? Do you think that this method could work? Can you suggest me a better method?

Thank you in advance for your useful kindness.

Best Regards,

Michele Canepa, University of Genoa.