RTC Stops while on battery - RCM3315

Started by "all...@yahoo.com [rabbit-semi]" January 12, 2017
I am have an issue with a few RCM3315 based devices where the RTC stops counting when the device is powered OFF. BBRAM is fine. RTC start counting where it left off when power is re-applied.

My main board hasn't changed since 2005. I only have a few devices with this issue.

/RES, /RESET_IN and VRAM are unconnected.

VBAT_EXT is connected directly to a CR2032.

Any ideas where to start looking?
Hi
Almost in Rabbit RCM 3700 the problem is the reset pull up resistance. Yo
can disconnect the pull up resistance or put a higher pull up resistance
Omar
El 01/12/2017 14:52, "a...@yahoo.com [rabbit-semi]" <
r...> escribió:
> I am have an issue with a few RCM3315 based devices where the RTC stops
> counting when the device is powered OFF. BBRAM is fine. RTC start
> counting where it left off when power is re-applied.
> My main board hasn't changed since 2005. I only have a few devices with
> this issue.
>
> /RES, /RESET_IN and VRAM are unconnected.
>
> VBAT_EXT is connected directly to a CR2032.
> Any ideas where to start looking?
Hi
Almost in Rabbit RCM 3700 the problem is the reset pull up resistance. Yo
can disconnect the pull up resistance or put a higher pull up resistance
Omar
El 01/12/2017 14:52, "a...@yahoo.com [rabbit-semi]" <
r...> escribió:
> I am have an issue with a few RCM3315 based devices where the RTC stops
> counting when the device is powered OFF. BBRAM is fine. RTC start
> counting where it left off when power is re-applied.
> My main board hasn't changed since 2005. I only have a few devices with
> this issue.
>
> /RES, /RESET_IN and VRAM are unconnected.
>
> VBAT_EXT is connected directly to a CR2032.
> Any ideas where to start looking?
Thanks for the info.

I have no resistor connected to either the /RES or the /RESET_IN pins. So is it the resistor on the RCM3315 that is wrong? Or is there supposed to be on at /RES? We have been using the board design for nearly 12 years and only now we have this issue, and only with a very few.