RTC Hours corruption

[lpcware]

Content originally posted in LPCWare by GWS on Thu Mar 03 17:04:39 MST 2016
I have an LPC1768 running FreeRTOS/lwIP.
The RTC Hours reading becomes corrupted at random times, roughly once or twice per day.  The Minutes reading is always correct.

I put a data-breakpoint across the RTC memory space watching for writes.  The data-breakpoint does never triggers when Hours becomes corrupted, indicating that the RTC peripheral became corrupted spuriously, without a rogue software write.

Two different users reported a similar RTC problem on an LPC2378 in 2011 on the Keil forum: http://www.keil.com/forum/18413/rtc-problem-in-lpc2378/.  Unfortunately no clear solution was presented.

Has anyone seen this problem or have a solution for it?  Thank you for your help.

[lpcware]

bump

[lpcware]

Content originally posted in LPCWare by GWS on Thu Mar 10 11:57:00 MST 2016
An update:
After making some software changes, the RTC hour corruption is inexplicably gone.

The software changes included the following:
1) Now reading time only from "Consolidated time registers" (CTIME0, CTIME1, CTIME3).  Never reading time from "Time counter registers" (SEC, MIN, HOUR, etc.).
2) Reading time only from high-ish priority interrupt once per second.  Formerly time was read in the Idle task.