[stephenthe1]

hi,
I've been going through a tutorial for using interrupts ("interrupts for dummies") and another one titled ("quadrature encoders"). this may be a vague question, I'm not sure. but what is "Port_B"? and what is "0xFF".
also, what are state machines (based on the current encoder position). are they used to determine what part of the "cycle" the encoder is going through.
lastly, just a thought, is does Port_B tell which of the 4 interrupts (4-7 was fired?), because these particular four are all identified under the "same name."
it seems that Port_B is used to reference interrupts 4-7, and then the 0xFF, where "FF" identifies which of those four ports was interrupted?
anything you can tell me to simplify this would be appreciated,
thanks,
Stephen P.