Re: RFC: osmo-clk-gen v2

2. allow different output voltages for two of the four banks of the Silabs chip https://osmocom.org/issues/3905

I'd use the DAC for software voltage tuning. Use 0R to select which bank uses which (default rail or programmable one, with just default to have 1/2 bank being the programmable vio).

3. should we keep the VCTCXO?

No. As you explained I think it's better to split functions and not overload this board.

4. Use SAMD XOSC / PLL / GCLK to allow lower reference frequencies https://osmocom.org/issues/3857 Where we'd actually use one of the SAMD GCLK outputs as one of the intputs to the Si5351C, and expose a GCLK input of the SAMD on an external header. This way, much lower frequencies can be used to driver the Si5351C. Or one could even go for deriving them from the SAMD RTC XTAL.

Does that mean the SAMD core would be running from the reference clock ? (and so wouldn't run if there is no reference connected)

Cheers,

Sylvain