18.1 Features
- General Purpose Input and Output Pins
            with Individual Configuration:
- Pull-up
 - Inverted I/O
 - Input voltage threshold
 
 - Interrupts and Events:
- Sense both edges
 - Sense rising edges
 - Sense falling edges
 - Sense low level
 
 - Optional Slew Rate Control per I/O Port
 - Asynchronous Pin Change Sensing That Can Wake the Device From All Sleep Modes
 - Efficient and Safe Access to Port
               Pins
- Hardware Read-Modify-Write (RMW) through dedicated toggle/clear/set registers
 - Mapping of often-used PORT registers into bit-accessible I/O memory space (virtual ports)
 
 
