It's true, I guess, that ATMEL and a few other mfg's parts require an external reset IC.

For a decade and a half or more after the development of microprocessors, there were no such things, however, and we got by just fine without 'em. It was, of course, possible to use a schmidt-trigger inverter or other hysteresis gate to drive the reset, but in all the years I put out microprocessor/microcontroller hardware, I've used a reset IC only about three times, and that was because a client specifically indicated he wanted to use one. I did that only because it was his money and because it was an ARM that was being used.

The things aren't free, though, and I surely prefer using an RC driving a hysteresis gate, perhaps buffered with an open-drain gate if it needs to drive the reset as well, as some versions do. Why is everyone so troubled by this reset hardware when I've never experienced even one problem with it?

Is this unique to ATMEL parts? That wouldn't surprise me!

RE