modifyit, I personally use the ADM690 or MAX690 supervisory ic in my designs because if the input pin is left unconnected or (tristated) the watchdog timer quits operation. This way during the bootloader initialization the port I have it connected to is also in a input or (tristate) mode so the bootload can take place. After which the port is programmed as an output and from then on the watch dog timer will have to be strobed atleast every 1.6 seconds before it will reset the micro and external circuitry. Try it, You'll like it....

Dave Purola,
N8NTA