ABSTRACT
This chapter discusses the 8051 microcontroller serial port programming. Since the serial port is closely related to the other subsystems and how to strike the balance in case of conflicting needs. It also deals with the serial ports of the IBM compatible PCs. The 8051 microcontroller based in SBC1 reads the high-order nibble of Port 1 and transmits it over the serial port. The PC redirects the four bits to SBC2, where they are emitted through the high-order nibble of Port 1. The front of the serial port subsystem has two hidden shift registers. The program interacts with the shift registers through buffers, which according to the 8051 terminology have a common name, SBUF. Along with the term serial port, a number of different names are being used in the PC world. Communication port (COM) or RS-232 port are other synonyms.
