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Audio noise depends on buffer-size of I2S DMA

Question asked by paintedman on Apr 9, 2015
Latest reply on May 14, 2015 by paintedman
Hi! I am using STM405RGT6 and TI PCM3060 audio codec. I use DMA to RX and TX I2S data. I2S configured to 96000 Hz. 

When I set buffer size, for example, 64 samples I get parasitic frequency peaks at every 1,5 kHz (96000/64 = 1500) - 1.5 kHz, 3 kHz, 4.5 kHz... If I set buffer size 256 samples I get parasitic frequency peaks at every 375 Hz and so on. Level of this noise is about -60 dB. I am just send recieved data back to codec, not using any processing.

How can I remove this noise?