Multi ADAT I/O with UAC 2.0?

[dtns]

I am using the sw_usb_audio-_sw_v8_1_0 for a project and wondering what has to be adjusted to allow for 2x (16ch) or 4x (32 ch) ADAT IO (without mixing).
Is increasing XUA_ADAT_TX / XUA_ADAT_RX enough?

[Ross]

"out of the box" the design only allows for one ADAT Rx and one Tx instance.

Some work would be required to:
- instantiate multiple ADAT rx/tx threads
- plum in the communications etc.

Adding an additional tx instance should be too much trouble, the SR/SMUX will be fixed for both.

Multiple rx will have wider issues - i.e. which one to clock off? - they'd both have to be from a related clock source to operate correctly at the sane time. Otherwise some sort of rate conversion would be required. This is typically why most off the shelf units only allow for one digital rx stream to be present.

If handling SMUX/sample-rates independently is required that would be a headache. The design currently uses 3 (8, 4 & 2 channels) interface alternates to select channel count (and therefore keep the channel count under the maximum for higher sample-rates). To have them independently set you'd need 3² interfaces alternates for two ADAT interfaces... Likely imposing some user restrictions on the design would be more tractable.