Datasheet

Table Of Contents
30
XMEGA E5 [DATASHEET]
Atmel-8153J–AVR-ATxmega8E5-ATxmega16E5-ATxmega32E5_Datasheet–11/2014
16. I/O Ports
16.1 Features
26 general purpose input and output pins with individual configuration
Output driver with configurable driver and pull settings:
Totem-pole
Wired-AND
Wired-OR
Bus-keeper
Inverted I/O
Input with asynchronous sensing with interrupts and events
Sense both edges
Sense rising edges
Sense falling edges
Sense low level
Optional pull-up and pull-down resistor on input and Wired-OR/AND configurations
Optional slew rate control per I/O port
Asynchronous pin change sensing that can wake the device from all sleep modes
One port interrupt with pin masking per I/O port
Efficient and safe access to port pins
Hardware read-modify-write through dedicated toggle/clear/set registers
Configuration of multiple pins in a single operation
Mapping of port registers into bit-accessible I/O memory space
Peripheral clocks output on port pin
Real-time counter clock output to port pin
Event channels can be output on port pin
Remapping of digital peripheral pin functions
Selectable USART and timer/counters input/output pin locations
Selectable Analog Comparator output pin locations
16.2 Overview
One port consists of up to eight pins ranging from pin 0 to 7. Each port pin can be configured as input or output with
configurable driver and pull settings. They also implement asynchronous input sensing with interrupt and events for
selectable pin change conditions.
Asynchronous pin-change sensing means that a pin change can wake the device from all sleep modes, including the
modes where no clocks are running.
All functions are individual and configurable per pin, but several pins can be configured in a single operation. The pins
have hardware read-modify-write (RMW) functionality for safe and correct change of drive value and/or pull resistor
configuration. The direction of one port pin can be changed without unintentionally changing the direction of any other
pin.
The port pin configuration also controls input and output selection of other device functions. It is possible to have both the
peripheral clock and the real-time clock output to a port pin, and available for external use. The same applies to events
from the event system that can be used to synchronize and control external functions. Other digital peripherals, such as
USART, timer/counters, and analog comparator output can be remapped to selectable pin locations in order to optimize
pin-out versus application needs.
The notations of the ports are PORTA, PORTC, PORTD, and PORTR.