[Arm-netbook] EOMA-68-A20 Card, RTC?

[Henrik Nordström]

fre 2013-08-16 klockan 11:30 -0400 skrev Scott Sullivan:
> Does the first A20 card have a built in RTC?

Not really. There is an internal RTC in the SoC, but to my best
understanding the EOMA68-A20 module lacks a suitable backup power to the
RTC so it will loose time when you do a hard power off.

> What is the policy on where the RTC should live?
> The I/O board or the card?

Good questoin. It boils mostly down to where can a suitable power source
be fitted to keep the RTC powered. I/O card is probably most favorable.

> Is it acceptable that neither have one?

Depends on the use case.

> Which wins if both have an RTC? (luck of kernel driver order?)

Undefined.

> I/O Board for all of the above, with no RTC at all being acceptable 
> (think router). I favour the I/O board as usually has the luxury of 
> space to include it. It's also a part of any design that won't change much.

And also much easier to handle power management. An RTC requires a
durable (but very low in amps) power source to keep the clock running
reliably.

Regards
Henrik