What happens to the Piccolo's SARAM on watchdog reset vs power-on reset

Kaveh,

On a cold reset (power-up), RAM contents are undefined.  They will contain garbage.  On a warm reset (e.g. reset pin or watchdog) RAM contents are unchanged.

Regards,

- David

David M. Alter said:

On a cold reset (power-up), RAM contents are undefined.  They will contain garbage.  On a warm reset (e.g. reset pin or watchdog) RAM contents are unchanged

That's the hardware answer.

Your software, on startup, is liable to do some initialisation of the RAM. If you want data to be presetved over a reset, then you must take care that your software's startup routines don't overwrite it...

One note - the boot ROM does use a small amount of memory for stack.  Some of these locations will be used by the boot ROM on any reset, including a watchdog.

The boot ROM reserved memory is documented in the reference manual for the particular device.

Regards

Lori