24.3.2.11.1 Overview

The device contains one infrared communication module (IRCOM) that is IrDA compatible for baud rates up to 115.2kbps.

The IRCOM is automatically enabled when the USART is set in IRCOM mode (by writing 0x2 to CTRLC.CMODE). The signals between the USART and the RX/TX pins are then routed through the module. The data on the TX/RX pins are the inverted value of the transmitted/received infrared pulse. It is also possible to select an event channel from the event system as input for the IRCOM receiver. This will disable the RX input from the USART pin.

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.