topic RTC on LPC1788 counts wierd? in LPC Microcontrollers

RTC on LPC1788 counts wierd?

lpcware — Wed, 15 Jun 2016 18:02:36 GMT

Content originally posted in LPCWare by FrankAndersen on Tue Apr 08 05:36:13 MST 2014
Hi All,

I think I have seen this in a forum somewhere before, but I can not find it.

I have a design with LPC1788, where I want to use the internal RTC. On some of the boards, it counts time just fine.

But now I have one where it increases both hours, minutes and seconds every seconds, it is proberly some kind of test mode.

But where is it enabled/ disabled, and why does it not disapear when the power is removed from the RTC.

I am begining to have doubts about using the internal RTC of the LPC1788, as I see all kind of topics regarding this?

Best regards,

Frank Andersen

Re: RTC on LPC1788 counts wierd?

lpcware — Wed, 15 Jun 2016 18:02:37 GMT

Content originally posted in LPCWare by LabRat on Tue Apr 08 07:12:23 MST 2014
Welcome to the Internal test mode :)

UM:

Quote:
Internal test mode controls. These bits must be 0 for normal RTC operation.

IIRC this mode can be enabled in CCR register. Check all bits there and reset the unused...

Re: RTC on LPC1788 counts wierd?

lpcware — Wed, 15 Jun 2016 18:02:37 GMT

Content originally posted in LPCWare by FrankAndersen on Tue Apr 08 23:03:09 MST 2014
Thank you.

Some how I came to the conclussion that 0x09, was Clk bit and Cal bit.

So now I am able to get it counting right.

Anyone out there using the internal rtc in LPC1788, with good expirences?

Best Regards,

Frank Andersen