MIMXRT1060-EVKB + AUD-EXP-42448 Left-Right Channel swap when in Mono

[vascofsantos]

I configured an audio loopback from my soundcard, into the CS42448 ADC, using the SAI eDMA driver with a ping-pong buffer strategy, back into the CS42448 DAC and into my soundcard again.

I am using I2S mode with Left and Right channels.

When using the kSAI_Stereo mode, channels come back in the expected order, but either kSAI_MonoLeft or kSAI_MonoRight swaps the channels. 

Is this a known issue?

[EdwinHz · Accepted solution]

Hi @vascofsantos,

This channel swap should not cause many issues as the channels are already in Mono. However, I don't think it is an indented behavior, so I will definitely report this internally for their deliberation. Thank you for reporting this.

BR,
Edwin.

[vascofsantos]

Thanks for your reply, @EdwinHz.

Yes, I agree it is easy enough to just pick kSAI_MonoRight instead of kSAI_MonoLeft upon initializing the I2S interface.

Please note that I am not sure whether this applies only to I2S mode (out of TDM, left/right justified, etc).

Either way, this post might help other people encountering the same behavior.

Best regards,

Vasco.