317
8331B–AVR–03/12
Atmel AVR XMEGA AU
For transmission, three pulse modulation schemes are available:
• 3/16 of the baud rate period
• Fixed programmable pulse time based on the peripheral clock frequency
• Pulse modulation disabled
For reception, a fixed programmable minimum high-level pulse width for the pulse to be decoded
as a logical 0 is used. Shorter pulses will then be discarded, and the bit will be decoded to logical
1 as if no pulse was received.
The module can only be used in combination with one USART at a time. Thus, IRCOM mode
must not be set for more than one USART at a time. This must be ensured in the user software.
24.2.1
Event System Filtering
The event system can be used as the receiver input. This enables IRCOM or USART input from
I/O pins or sources other than the corresponding RX pin. If event system input is enabled, input
from the USART's RX pin is automatically disabled. The event system has a digital input filter
(DIF) on the event channels that can be used for filtering. Refer to
”
for details on using the event system.