2008-04-05 09:09:25     DMA Problem

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2008-04-05 09:09:25     DMA Problem

Appalayagari Sreedhar (INDIA)

Message: 53682   




I am working with BF533 rev 0.5. my board has 60fps display device, I am using dma sport buffers in autobuffer mode for transmitting and receiving audio data. I am using the ping pong concept.


DMA0 for PPI (GPIO mode) and Sport0 Rx DMA1 and Sport0 Tx DMA2.


when i try to run the codec I am hearing noise, can anyone provide some clues what might be happening.I could see that the ping and pong counts are not the same.


is it iam copying the audio data into the same sport dma buffer which i have copied in my previous interrupt service?.


Can anyone provide some idea how to debug this noise problem.


Thanks in advance, Sreedhar.






2008-04-05 23:49:07     Re: DMA Problem


Message: 53692    Sreedhar:


> when i try to run the codec I am hearing noise,


there is not enough details on your system to understand what could be going on.


did you try one of the existing audio drivers? You should not be writing audio drivers yourself.