[sdiy] gates and clock inputs to a microprocessor

[Danjel van Tijn]

I am working on module where I have a microprocessor receive gate/trig
inputs for clock and reset controls.

what do I need in terms of analog circuits to condition those inputs?
e.g.
-for input over voltage protection would I use a resistor plus 5V zener?
-comparator to allow low voltage signals trigger?
-series diode to protect from negative voltage?

Also the uP will be outputting gate signals. Should these be buffered
or can I just drive straight from the output pins?  (it is an
atmega168)

Also if the input pins of the microprocess are using pullups, how
would I have an incoming pulse trigger on rising edge? would I need to
put it through an inverter?

I am sure all this stuff has been covered and well documented in
schematics. I am going to head over to MFOS to get some ideas but
thought it would be good to check some other resources.


cheers,
Danjel