PRSNT0 and PRSNT1 signals

Please what is the purpose of the PRSNT0 and PRSNT1 signals? I haven’t found anything in the documentation.
Do I need to implement these signals when designing custom carrier board?

I’ve seen that this was already asked in

but there was not clear answer if these signals are needed or not

Many thanks

It is to prevent hot-plug, better to follow the design.

I’m very sorry, but I’m not sure I know how to interpret this answer:

  1. “prevent hot plug” => SoM is screwed to the carrier board so there is no chance of any hot plugging. Or was it meant differently?

  2. “follow the design” => what design? There is no description of these signals in the manual, except that they are listed in the pin list.

I would really appreciate bit more insight into the functionality of these 2 signals, so our designers can make own qualified decision how to implement it.

Many thanks

There will be related description in new OEM DG doc. You can leave them unused if no hot-plug risk on your design. What we suggested is better to keep the PRSNT0 and PRSNT1 same as schematic as backup design since it is a simple circuit.

Ok so recomended is:

  • PRSNT0 to GND (as in carrier board design) => clear
  • PRSTN1 -The functionality of Carrier board is not clear to me, there is mechanical switch (S501) and 4k7 pull-up to 3V3 and pull-down to GND (probably not populated?). Which of this circuitry is recommended ? Is just 4k7 pull-up sufficient or do I need something more ? (we control the power-up sequence by another CPU and plan no mechanical switches in the design)

Many thanks

“PRSNT0 to GND” + “PRSNT1 with 4.7k pu to 3.3v”.

Ok, perfect. Thx a lot for this recomendation