XCore Exchange

Hi,

Currently the USB Audio 2.0 Reference Design supports bit perfect audio data up to 24-bit @ 192kHz. Is it anyway to make to to support 32bit data @ 192kHz too?

Many thanks,

Pat

The audio codec used only supports 24 bits.

http://www.cirrus.com/en/pubs/proDatash ... 270_F1.pdf

Hi Pat,

At this moment in time the XMOS USB Audio 2.0 Reference Design is designed to support up to 24bit/192kHz.

It can be (and has been) modified by the user to support 32bit and up to 384kHz, but this is not included or supported in the reference design.

I hope this helps.

Kind Regards,
Corin

>The audio codec used only supports 24 bits.

Yes, correct. I will jumper out the I2S signal to another 32 bit DAC chip.

"It can be (and has been) modified by the user to support 32bit and up to 384kHz. "

There is MAX_FREQ in the firmware which I can now see to change the max supported freq.

What I am still unsure is the 32bit thing, as SPDIF standard only support a max audio date length of 24bit (20 + 4 AUX bits), how can one transmit a 32bit audio data via SPDIF?

Many thanks,

Pat

ah... let me answer my own question ... SPDIF can't do 32bit audio data. Yes USB can, but then USB must directly convert to I2S, can't convert to SPDIF first.

I still have the question, how do I modify the XMOS to make it stream 32bit USB audio data?

Many thanks,

Pat

patw,

I'm intrigued as to why you would want to do so.
The is not an ADC or DAC in the world that can resolve to one part in 4 billion.

there are DAC chip out there which support that resolution, whether it makes a difference in final listening is another matter.

Hi Corin,

"It can be (and has been) modified by the user to support 32bit and up to 384kHz, but this is not included or supported in the reference design."

Can you kindly give me some pointer in this matter, especially the 32bit support in the USB.

Many thanks for your help. :P

Pat

Does your question include a Windows driver for that or only the SW on the XMOS side ?