I just tried to reset the watchdog to its "off"-state. Which failed ...

I used the bootloader for this purpose and flipped the watchdog-button to "disabled", killed the flash-memory (the shortcut for "wipe memory" is a "k", so it must mean kill, right?), and re-read the registers, just to see that there was no change. I couldn't change them manually from the bootloader and the "timed access" has me confused, as it isn't described at what point in time I am supposed to write to that part of memory.

Following these experiences I had a little check-up on the errata for the controller and found out that revision A3 (which I consider myself unfortunate to own) has exactly this one bug concerning the OCR not being reset during kill-procedures (I just love the tone of that).

Of course, I don't have any other flash-based micro's from Dallas in a DIP-case and don't want to mess around with PLCC-sockets and lots of jumper wires. So I ordered two samples of the '420 in the hope that they arrive in a new version.

/Thomas