Department of Computer Scien
ce and Information Engineering
National Cheng Kung University, TAIWAN
HANEL
OTHER MODES OF THE 82558255 in Mode 1:
I/O With Handshaking Capability
One of the most powerful features of 8255 is to handle handshaking signalsHandshaking refers to the process of two intelligent devices communicating back and forth
¾Example--printer
Mode 1: outputting data with handshaking signals
¾As show in Figure 15-14¾A and B can be used to send data to device with handshaking signals¾Handshaking signals are provided by port C¾Figure 15-15 provides a timing diagram