There are possibilities to configure the usb app to run as i2s slave (some discussion in an earlier thread ). In my application I do want to run the app on xcore-200 chip and use it as an usb-to-i2s bridge. I have a DSP that will act as i2s master.
My question is if I still need to supply an audio clock (either 22.6 or 24.6MHz) to the xmos chip (on the MCA board, the clock pins XS1_PORT_1F and XS1_PORT_1L (tile1))?
In principle, the following clock signals should suffice
- LRCLK from DSP
- BCLK from DSP
- 24MHz main processor clock
AudioHwConfig() needs audio clock, but should be fine without since the app is not responsible for any external configurations in my system (e.g. ADC/DAC), besides eventually telling the DSP about the sample rate from the USB.
In my usb_app (example, see thread) I will also perform sample rate conversion with lib_src. But as far as I can see, src_manager does not use the audio clock frequency.
/AJ
required clocks running sw_usb_audio in i2s slave mode Topic is solved
-
- Active Member
- Posts: 35
- Joined: Wed Jan 24, 2018 9:13 am
-
- XCore Legend
- Posts: 1913
- Joined: Thu Jun 10, 2010 11:43 am
Hi. Not an audio developer but believe infiniteimprobability references this topic here:
http://www.xcore.com/viewtopic.php?f=7& ... ave#p32680
http://www.xcore.com/viewtopic.php?f=7& ... ave#p32680