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real time problem

Started by seba...@seareka.com April 2, 2008
Hi everyone,

I am working on DSK5416 and CCS.
I'm doing real-time using DMA and McBSP to communicate with the codec. I'm working with 16 bits words and with DSP/BIOS configuration.
I would like to know if the problem that I have is coming from data alignment.
After interruption (full buffer: 1024 words of 16 bits) I use the following function:
Interrupt function(){
int i=0,maxisync,maxicanal;
for (i=0;i OutBuffer[i]=InBuffer[i];
}
// Input FFT
cbrev(OutBuffer,OutBuffer,NFFT/2);
rfft(OutBuffer,NFFT,1);
// Matched Filter
for (i=0; i FiltreAdaptesync[i]=(OutBuffer[i]/10*chirpsync[i]/10);
}
/*cbrev(FiltreAdaptesync,FiltreAdaptesync,NFFT/2);
rifft(FiltreAdaptesync,NFFT,1);*/
}
I also have the following extra configuration file:

-l audioIODmacfg.cmd

SECTIONS{
InBufferSect: > IDATA PAGE 1,align(0x800)
OutBufferSect: > IDATA PAGE 1,align(0x800)
FAsyncBufferSect: > IDATA PAGE 1,align(0x800)
}
As you can see after interruption I’m doing an fft of the receive buffer and a matched filtering.
My problem is when I’m computing the ifft of vector FiltreAdaptesync the result of the fft OutBuffer is not good. However, when I don’t compute the ifft, then the result of OutBuffer fft is good. I don’t understand why.

Thank you for your help
getthematrix