30.1.1.1 Enabling the Transmitter

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

  • The Transmit Enable (TXEN) bit is set to ‘1’ to enable the transmitter circuitry of the EUSART
  • The EUSART Mode Select (SYNC) bit is set to ‘0’ to configure the EUSART for asynchronous operation
  • The Serial Port Enable (SPEN) bit is set to ‘1’ to enable the EUSART interface and to enable automatically 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 in the PIRx register is set when the TXEN enable bit is set and the Transmit Shift Register (TSR) is Idle.