Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

HANEL

PROGRAMMING THE 8255Connecting 8031/51 to

8255

‰The 8255 chip is programmed in any of the 4 modes

¾mentioned earlier by sending a byte (Intel calls it a control word) to the control register of 8255

‰We must first find the port address assigned to each of ports A, B ,C and the control register

¾called mapping the I/O port