Upon completion of this chapter, you will be able to:
» Describe how to expand the I/O ports of the 8031/51 by connecting
it to an 8255 chip
» List the 3 ports of the 8255 and describe their features
» Explain the use of the control register of the 8255 in selecting a mode
» Define the modes of the 8255
» Define the term memory-mapped I/O and describe its application
» Program the 8255 as a simple I/O port for connection with devices
such as stepper motors, LCDs, and ADC devices
» Interface the 8051 with external devices such as stepper
motors, LCDs, and ADC devices via the 8255
» Diagram the 8031 interface with external program ROM and the 8255
» Explain how address aliases are used in address decoding techniques
» Program the 8255 as a simple I/O port in 8051 C
