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Problem with the IIR accelerator on the ADSP-21469 Ez-Kit with Audio Extension

Question asked by on Apr 29, 2013
Latest reply on May 14, 2013 by Mitesh


I'm wanted to include a IIR filtering into a program which is based on the Sample Based Talkthrough example. Therefore I started with the Talkthrough_IIR_Accelerator example and modified it slightly (different Block Size, and different filter coeffs). This example works as expected. A linear sweep is faded out as it should. I attached a picture of a loopback I recorded with Adobe Audition.


When I now try to use the IIR Accelerator Code in my Sample_Based_Talkthrough I get the following warnings from the compiler, although I use exactly the same code, as in the IIR accelerator example:


.\IIR_Accelerator.C", line 55: cc0144: {D} warning: a value of type "float *"

          cannot be used to initialize an entity of type "int"

  input_left,// II = Input data index register


\IIR_Accelerator.C", line 69: cc0513: {D} warning: a value of type "int *"

          cannot be assigned to an entity of type "int"



.\IIR_Accelerator.C", line 88: cc0513: {D} warning: a value of type "int *"

          cannot be assigned to an entity of type "unsigned int"



The audio output is also corrupted. You can see what happens on the picture Audition_Matrix_out.png.

I already tried to cast the variables. This kept the warnings away, but the audio output was still the same. I'm trying to solve this issue for quite some time now, but I don't see what I did different to the IIR accelerator example.


Thanks in advance,