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.