Am working with an ADuC812 and was hoping to preserve some data in internal RAM notwithstanding an external reset to the chip.

I've seen it asserted here that external reset with power on throughout will not affect internal RAM, but could it be that that for the ADuC internal RAM is cleared?

Even modified the startup code such that the first instructions are to enter an infinite loop if the contents of a particular address are non-zero, where it is known that the datum is non-zero before the reset, but the unit comes right up, proving that what was non-zero is now zero.

Is this standard 8052 behavior or is it peculiar to the ADuC?

Cheers -- ewd