SAI synchronous audio mode - CTIMER

[mrecoskie]

Hi,

I am running the RT1064 EVK board.  MCUXpresso IDE v11.5

I am trying to convert the 'composite_hid_audio_unified' sample to synchronous audio transmission.  When enabling the ‘USB_DEVICE_AUDIO_USE_SYNC_MODE’ define it requires a CTimer implementation (specifically ‘fsl_ctimer.h’)

I can’t find what should be enabled through the ‘Manage SDK Components’ menu to make this work.  Does someone know how CTimer can be enabled?

Thanks

Mark

[kerryzhou]

Hi @mrecoskie ,

    I already get the internal information.

   For USB IP on RT4bit series chip, it doesn't have the SCTimer to adjust the audio clock. So our SDK for RT4bit series only use the Asynchronous mode. Actually, the Asynchronous mode is the most reliable way to sync usb audio. 

   Please help to check, whether your Host do not support the Asynchronous mode or not?

   If you must use the Asynchronous mode, please let me know, our internal side have ever implemented a project that use synchronous mode, it uses the sof interrupt to adjust the audio pll, but I still don't have it, if you need it, we will apply for it internally.

   So, please tell me, whether you must need to use synchronous mode.

Best Regards,

Kerry

[mrecoskie]

Hi Kerry,

Yes - we need synchronous mode.  Are you able to provide us a solution?

Thanks

Mark

[kerryzhou]

Hi @mrecoskie ,

  Please check the synchronous project in the private message.

Wish it helps you!

Best Regards,

kerry

[kerryzhou]

Hi @mrecoskie ,

   I think, you mention this part:

In fact, the ctimer is not the RT1064 peripheral, it is the RT600&LPC peripheral, that's why you can't add it.

So, ctimer can't be used in the RT10XX.

Wish it helps you!

Best Regards,

Kerry

[mrecoskie]

Hi Kerry,

Yes.  This is the part I'm referring to.  

What would you recommend using as an alternative to the ctimer for synchronous audio mode?  And is there any example usage?

Thanks,

Mark

[kerryzhou]

Hi @mrecoskie ,

  From the directly SDK project with ‘USB_DEVICE_AUDIO_USE_SYNC_MODE’ define, I think it can't be supported for the SYNC_MODE.

  Please keep patient, I already help you to check it internally, whether it has any other method or not, any updated information, I will let you know, thanks a lot for your understanding.

Best Regards,

Kerry