Delayed Receive Interrupt

When operating in Half Duplex mode, where the microcontroller needs to reverse the transceiver direction after a reception, it may be more convenient to hold off the UxRXIF interrupt until the end of the Stop bits to avoid line contention. The user selects when the UxRXIF interrupt occurs with the STPMD bit. When STPMD is ‘1’, the UxRXIF interrupt occurs at the end of the last Stop bit. When STPMD is ‘0’, the UxRXIF interrupt occurs when the received byte is stored in the receive FIFO. When STP = 10, the store operation is performed in the middle of the second Stop bit, otherwise, it is performed in the middle of the first Stop bit.

The FERIF and PERIF interrupts are not delayed with STPMD. When STPMD is set, the preferred indicator for reversing transceiver direction is the UxRXIF interrupt because it is delayed whereas the others are not.