EG915U & PCM audio

Hi,

I’m currently trying to setup audio communication between EG915U and our MCU.
When I send the command AT+QDAI=1,1,0,4,0,0,1,1 to configure the audio as PCM slave, the module replies OK, however this has no effect, and when I try to read the settings with AT+QDAI?, it alway replies with +QDAI: 3,1,1,4,0,0,1,1 (instead of 1,1,0,4,0,0,1,1).
Even after a reboot, the QDAI settings remains 3,1,1,4,0,0,1,1

One more thing, the AT+QAUDSW (Select Codec) doesn’t work either. Whenever I try to select external codec with AT+QAUDSW=0, the modem returns an error (+CME ERROR: 901)

Please help me to configure the module so it can send / receive PCM audio data.
Thanks,

Simon

Please check your schematic diagram.
The extenal codec maybe broken.