27.1.1.1 Enabling the Transmitter

The EUSART transmitter is enabled for asynchronous operations by configuring the following three control bits:

  • TXEN = 1 (enables the transmitter circuitry of the EUSART)
  • SYNC = 0 (configures the EUSART for asynchronous operation)
  • SPEN = 1 (enables the EUSART and automatically enables the output drivers for the RxyPPS selected as the TXx/CKx output)

All other EUSART control bits are assumed to be in their default state.

If the TXx/CKx pin is shared with an analog peripheral, the analog I/O function must be disabled by clearing the corresponding ANSEL bit.

Important: The TXxIF Transmitter Interrupt flag is set when the TXEN enable bit is set and the TSR is idle.