Have not tested it yet, but figured I would ask....
Can an 8051 be reset directly with a membrane type switch? Specifically, the Atmel AT89S52 (but at some point the design / availability could mandate some other 8051 derivative part, as yet unknown.)
I plan to use a 4.7k / 1uF combination, and simply take Pin-9 high to reset it.
For this particular type of project, I would normally use a uPC that either has internal power-up reset on-chip, or maybe even an outboard device like a DS1232 or something.
BUT, if it's acceptable to just use an non-debounced, unconditioned, membrane switch to reset the uPC, this particular design could benefit from the reduced parts count. Note that I would probably also use a software watchdog, and I believe the AT89S52 has a power rail monitor for brownout already built-in (which would also have been provided by a DS1232 or equiv.)
What do you think?