Datasheet

135
XMEGA B [DATASHEET]
8291B–AVR–01/2013
12.9 Clock and Event Output
It is possible to output the peripheral clock and event channel 0 events to a pin. This can be used to clock, control, and
synchronize external functions and hardware to internal device timing. The output port pin is selectable. If an event
occurs, it remains visible on the port pin as long as the event lasts; normally one peripheral clock cycle.
12.10 Multi-pin configuration
The multi-pin configuration function is used to configure multiple port pins using a single write operation to only one of the
port pin configuration registers. A mask register decides which port pin is configured when one port pin register is written,
while avoiding several pins being written the same way during identical write operations.
12.11 Virtual Ports
Virtual port registers allow the port registers to be mapped virtually in the bit-accessible I/O memory space. When this is
done, writing to the virtual port register will be the same as writing to the real port register. This enables the use of I/O
memory-specific instructions, such as bit-manipulation instructions, on a port register that normally resides in the
extended I/O memory space. There are four virtual ports, and so four ports can be mapped at the same time.