I'm developing a product based on this board (variation of this design though...).
I have looked into the example BSP for this board that I have downloaded. I have couple of questions:
1. Currently, the USB audio supports only 16-bit samples. How do I change it to support 24-bit audio sample coming from the USB host?
2. Continue the above question, are there any other changes in the audio path that are required when receiving 24-bit audio samples instead of 16-bit?
3. I'm planning to support only 48KHz sample rate. Should the ASRC module still be used? If so, how should I configure it (output frequency to the DAC should be also 48KHz, unless there are benefits to upscale it to 96KHz, which the DAC supports).
Regards,
Yair Raz
Innovo Concepts, Inc.
10:10pm
Hi Yair,
You'll see that in ithe ST BSP's on our website, the USB data coming in is 16-bits. The AWE Core requires that 32-bit data be pumped into the signal processing design, so you will have to convert your 24-bit data into 32-bit data, as well as potentially changing the size of certain buffers. You can use the existing code as a reference and follow the audio path and update as required.
The ASRC provided as part of the ST BSPs only supports 32 kHz <--> 48 kHz and 48 kHz <--> 48 kHz conversions. When getting audio from USB, you should continue to use the ASRC since the clock from the USB source and your targets clock will not be synchronous.
-Axel