I've got an ASIC circa 1990 (so NMOS or CMOS probably?) with some NC pins with traces that lead off the board for testing. I'd like to know if they're inputs or outputs but I don't know how to do this safely with common parts.
Can I just touch VCC through a current limited LED to the pin to see if it sinks current? If it does, that makes it either an input or a low output, right? But then what?
Thanks!
Can I just touch VCC through a current limited LED to the pin to see if it sinks current? If it does, that makes it either an input or a low output, right? But then what?
Thanks!