M4 appears blocked while RTC registers are updating.

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by philippschrader on Fri May 29 10:43:28 MST 2015
Hi all,

I'm looking for some insight into some behaviour I'm observing on the LPC4357.

Steps to reproduce:
1) The M4 sending a message to the M0APP via shared memory to change the time.
2) M0APP receives message and updates the time by writing the corresponding RTC registers
3) Everything continues fine
4) About a second or two after updating the time, the M4 appears to stop whatever it's doing and just sits there for ~1 second

As far as I can tell, the M4 is just blocked.

I've tried:
- Adding assert statements to all the interrupt routines to see if any of them trigger.
- Interrupting the processor in the debugger, but it also appears to just wait until the M4 is unblocked and then interrupts whatever code it was running before the M4 got blocked.

Does anyone have any insight or thoughts on what this could be?