Simple filter implementation for TMS320C6748 on top of mcasp example from Starterware

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Hi guys,

This is my implementation of FIR filter (coeffs are generated by matlab fdatool, window(kneser), order 10):
However, the code is still not working what should I do?

1) I noticed that txBuf and rxBuf are in unsigned char type and 4 bytes per sample, does it mean that I need to take four consecutive chars as one value?

2) How data is stored in rxBuf, left and right channels are alternating?

3) Is the samples stored in rxBuf compressed, or it is raw data acquired from ADC?

I know that I need to copy new (ORDER-1) samples into the end of input buffer, but for now I don't want to deal with that problem.

Or, is there any other way where I can set a filter type and value, for example in codec?

Thanks,
YK


static float xBuf[AUDIO_BUF_SIZE+ORDER-1]; //input buffer
static float yBuf[AUDIO_BUF_SIZE]; //output buffer

const float COEFFS[ORDER]= {0.0593, 0.0383, -0.0397, -0.1522, -0.2519, 0.7083, -0.2519, -0.1522, -0.0397, 0.0383, 0.0593}; //coeffs are flipped

. . . . .

memcpy((void *)xBuf, (void *)rxBufPtr[lastFullRxBuf], AUDIO_BUF_SIZE);

for(i=0; i < AUDIO_BUF_SIZE; i++)
{
   sum = 0;
   for( j=0 ; j < ORDER ; j++)  
   {
      sum += xBuf[i+j]*COEFFS[j];
   }
   yBuf[i] = sum;
}

memcpy((void *)txBufPtr[lastSentTxBuf], (void *)yBuf, AUDIO_BUF_SIZE);

.....