The 8051 Microcontroller and Embedded

Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

HANEL

PROGRAMMING THE 82558255 Features

(cont’)

8255 Block Diagram

8 2 5 5

D7 –D0 RD WR A0 A1

CS

PA PB PC RESET

It has three separately accessible 8-bit ports, A, B, and C¾They can be programmed to input or output and can be changed dynamically¾They have handshaking capability