However the required ULPI pins are not all available on the board's GPIO pins so it is next to impossible to connect an external PHY.
You will need HS for any modern audio rate (192k, 24bit as 32bit stereo for example).
Internal PHY makes it easier to implement but external support is achievable but the PCB design needs to support the higher frequencies. Probably also needs a 4 layer board as a minimum.
Internal PHY makes it easier to implement but external support is achievable but the PCB design needs to support the higher frequencies. Probably also needs a 4 layer board as a minimum.
This is good but not mandatory, I've successfully made few HS devices with ULPI USB PHY on 2 layers boards.
UAC2 works also with USB FS up to 96k/24. USB HS would be useful if an external dac is used instead of the on-board dac.
Not having to support UAC1. Most of these development boards have audio codecs that only support 96k/24 so FS is sufficient.
Not clear.
UAC1 is much easy than UAC2, what the sense to use UAC2 with 96/42 max.?
(I'm talking of course not about UAC1 at PCM27xx or PCM29xx, with adaptive sync, but about microcontroller and UAC1 with async. sync.)
UAC1 is much easy than UAC2, what the sense to use UAC2 with 96/42 max.?
(I'm talking of course not about UAC1 at PCM27xx or PCM29xx, with adaptive sync, but about microcontroller and UAC1 with async. sync.)
UAC1 and UAC2 are relatively as easy to implement. I have implemented both and the difference is mainly in the setup & control requests. Makes much more sense to implement just UAC2.
