Lpc2000

When I first started with the LPC210x and Watchdog my board would 
sporadically crash - mainly then when I was dumping data to the 
serial port (lots of SCI interrupts).

I decided to protect the feed sequence from interrupts and this 
cured the problem - since then the system is as solid as a rock.

Therefore the feed sequence should absolutely be protected against 
interrupts!!!

regards

Mark Butcher

www.mjbc.ch



--- In lpc2000@yahoogroups.com, "extra300_it" <roberto.labaa@l...> 
wrote:
> 
> Hello,
> One question about WDT feeding.
> 
> The user manual is (once more) not exatcly clear about WDT refresh.
> It says that after writing 0xAA to WDTFEED, 'the next operation in 
> watchdog register space should be a write 0x55 to WDTFEED', 
otherwise 
> the watchdog will reset the cpu even if the timer is not yet 
elapsed.
> 
> What happens if one interrupt triggers between 0xAA and 0x55?
> 
> I see the wdt resets cpu, even if the ISR does not affect WDT 
> register space.
> 
> Do I need to disable interrupts before feeding WDT?
> 
> Thank you.