SM2 when £¼1, enables multiprocessor operation in modes 2 and 3
REN when £¼1, enables serial reception
TB8 Used in multiprocessor operation in modes 2 and 3
RB8 Used in multiprocessor operation in modes 2 and 3
TI Transmit interrupt flag, set when byte transmission is completed.
Must be cleared by software
RI Receive interrupt flag, set when a byte in the serial buffer (SBUF) is
ready for retrieval. Must be cleared by software
Practical tip. Although not apparent in the device data sheet and not required
in the simulation, transmission start-up problems may occur in the hardware if
TI is not initially set to 1 by the software.