25.3.1 Initialization

Full-Duplex Mode:

  1. Set the baud rate (USARTn.BAUD).
  2. Set the mode of operation (USARTn.CTRLA).
  3. Enable the transmitter and the receiver (USARTn.CTRLB).
  4. Configure the frame format (USARTn.CTRLC and USARTn.CTRLD).
  5. Enable the USART (USARTn.CTRLA).

One-Wire Half-Duplex Mode:

  1. Internally connect the TXD to the USART receiver (the LBME bit in the USARTn.CTRLE register).
  2. Enable internal pull-up for the RX/TX pin (the PULLUPEN bit in the PORTx.PINnCTRL register).
  3. Enable Open-Drain mode (the ODME bit in the USARTn.CTRLE register).
  4. Perform the initialization steps for Full-Duplex Mode as described above.