LPC2138: watchdog as periodic timer ?

Started by Marcio Zaquela June 29, 2006
Hi guys,

I searched the messages and I couldn't find a final answer concerning this issue.

Is it possible to use the watchdog as a periodic timer or not ?

According LPC2138 user manual it is not possible:

"WDINT: The Watchdog Interrupt Flag is set when the watchdog times out. This flag is
cleared when any reset occurs. Once the watchdog interrupt is serviced, it can be
disabled in the VIC or the watchdog interrupt request will be generated indefinitely"

Is there any way to work around this WDINT feature ?

Regards,
Marcio



An Engineer's Guide to the LPC2100 Series

On 6/29/06, Marcio Zaquela wrote:
>
> Hi guys,
>
> I searched the messages and I couldn't find a final answer concerning this issue.
>
> Is it possible to use the watchdog as a periodic timer or not ?
>
> According LPC2138 user manual it is not possible:
>
> "WDINT: The Watchdog Interrupt Flag is set when the watchdog times out. This flag is
> cleared when any reset occurs. Once the watchdog interrupt is serviced, it can be
> disabled in the VIC or the watchdog interrupt request will be generated indefinitely"
>
> Is there any way to work around this WDINT feature ?
>
> Regards,
> Marcio

Probably not - the watchdog interrupt flag can only be cleared by a
processor reset.
I think the basic reasoning is that you can attach an interrupt
handler to capture stack frame, etc. to report on why the WDT tripped
before you go to reset.