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RTC values reset to zero

Started by tayyaba_ch June 2, 2009
Hi
i am working with LPC 2368 and using 32k external crystal for RTC and cell as RTC power supply.
RTC is working fine, i can set and read RTC successfully, but some times it resets to 0(hour,minutes,seconds,day,week,month,year) randomly and by setting again its value it works properly.
Regards

An Engineer's Guide to the LPC2100 Series

Hi
i am working with LPC 2368 and using 32k external crystal for RTC and cell as
RTC power supply.
RTC is working fine, i can set and read RTC successfully, but some times it
resets to 0(hour,minutes,seconds,day,week,month,year) randomly and by setting
again its value it works properly.
Regards

Hi:
There could be several reasons why the RTC resets:

1. MCU Reset: have you check that the RTC reset doesn't coincide with a full MCU reset?

2. It could be possible that you're overwritting the RTC Timer Counter registers with 0. Maybe a rogue pointer?

3. Or resetting the RTC (see CCR register)?

Regards,

Alex

--- In l..., "tayyaba_ch" wrote:
>
> Hi
> i am working with LPC 2368 and using 32k external crystal for RTC and cell as RTC power supply.
> RTC is working fine, i can set and read RTC successfully, but some times it resets to 0(hour,minutes,seconds,day,week,month,year) randomly and by setting again its value it works properly.
> Regards
>

--- In l..., "tayyaba_ch" wrote:
>
> Hi
> i am working with LPC 2368 and using 32k external crystal for RTC and cell as
> RTC power supply.
> RTC is working fine, i can set and read RTC successfully, but some times it
> resets to 0(hour,minutes,seconds,day,week,month,year) randomly and by setting
> again its value it works properly.
> Regards
>

So, do you have a question ?

Sounds like a hardware problem.
What is the rest of the software doing ?
Did you write the code yourself ?

When you power down the system, does the battery (cell) also power down ?

don

Hi,

Check your time settings that is it is 12 hr or 24 hrs.
It will shows the time 00:00:00 at 12:0:0 .

On Wed, Jun 3, 2009 at 8:22 AM, tayyaba_ch wrote:
> Hi
> i am working with LPC 2368 and using 32k external crystal for RTC and cell
> as
> RTC power supply.
> RTC is working fine, i can set and read RTC successfully, but some times it
> resets to 0(hour,minutes,seconds,day,week,month,year) randomly and by
> setting
> again its value it works properly.
>
> Regards

--
Thanks & Regards,
Chetna N.Kharkar