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).
Note:
- 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).
Note:
- 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