Full-Duplex Mode:
- 1.Set the baud rate (USARTn.BAUD).
- 2.Set the frame format and mode of operation (USARTn.CTRLC).
- 3.Configure the TXD pin as an output.
- 4.Enable the transmitter and the receiver (USARTn.CTRLB).
Notes:
- For interrupt-driven USART operation, global interrupts must be disabled during the initialization
- Before doing a reinitialization with a changed baud rate or frame format, be sure that there are no ongoing transmissions while the registers are changed
One-Wire Half-Duplex Mode:
- 1.Internally connect the TXD to the USART receiver (the LBME bit in the USARTn.CTRLA 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.CTRLB register).
- 4.Set the baud rate (USARTn.BAUD).
- 5.Set the frame format and mode of operation (USARTn.CTRLC).
- 6.Enable the transmitter and the receiver (USARTn.CTRLB).
Notes:
- When Open-Drain mode is enabled, the TXD pin is automatically set to output by hardware
- For interrupt-driven USART operation, global interrupts must be disabled during the initialization
- Before doing a reinitialization with a changed baud rate or frame format, be sure that there are no ongoing transmissions while the registers are changed