I/O PORTS AND SPECIAL FUNCTION REGISTERS
In this chapter, the reader is introduced to some Special Function Registers (SFRs) and the overall architecture of the I/O ports of MCS-51. After completion of the chapter, the reader should be able to understand
- Names, locations (addresses), reset values and functions of all SFRs.
- Details of PSW, accumulator, B register, SP and I/O port registers.
- How to select any one of the four register banks of MCS-51.
- Bit addresses of different SFRs.
- Architecture and functioning of all four I/O ports of MCS-51.
- Difference between MCS-51 I/O ports and 8255 I/O ports.
3.1 | Introduction
In Chapter 2, it was mentioned that some of the internal memory locations (80H to FFH) of MCS-51 contain SFRs. ...