[En-Nut-Discussion] SAM7X Watchdog

[Jix Electronics]

Hi,

I can't comment the comment, but seems that this line is for feeding the
watchdog (restart of watchdog timer). It could be removed when feature is
disabled at startup.

Jix


Harald Kipp wrote:
> Hi,
>
> Anyone able to explain this part of arch/arm/os/nutinit.c to me?
>
> #ifdef MCU_AT91SAM7X256
>         /*
>          * We have only one chance to disable the WDT by writing WDT_MR.
 This
>          * may cause trouble when debug in RAM.  If code burned in flash
enabled
>          * WDT, we have no idea to disable but clear it.
>          */
>         outr(WDT_WDCR, 0xA5000000 | WDT_WDRSTT);
> #endif
>
> After adding
>
>         /*
>          * The watchdog is enabled after processor reset. Disable it.
>          */
>         ldr     r1, =WDT_BASE
>         ldr     r0, =WDT_WDDIS
>         str     r0, [r1, #WDT_MR_OFF]
>
> to crtat91sam7x256_rom.S, the triggering in the idle thread shown
> above can be removed, right?
>
> If I understood everything correctly, the watchdog disable
> must be configurable, because WDT_MR can be written once only.
>
> Did I overlook something?
>
> Harald
>
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