The Microcontroller Idea Book - Jan Axelson's Lakeview Research

Wireless Links
Figure 12-7. Using an 8255 to control and access an infrared receiver.
and just read Port B once a minute, or on user request, or trigger the reading by some other
factor under program control.
As with the encoder circuit, you don’t have to use an 8255 to read and write to the decoder.
Any latched port outputs will do for A1-A4, and any port inputs will do for D6-D9. Because
the decoder latches the data, you don’t need additional input latches. If the circuit will receive
data from only one address, you can hardwire the decoder’s A1-A5 and free up four bits on
the 8255 for other uses.
You can transmit to Figure 12-7’s circuit with either a manual or computer-controlled
transmitter. Set the transmitter’s address inputs to match the receiver’s address, select the
data you want to send, transmit, and view the received data on the 8052-BASIC system’s
host display.
The Microcontroller Idea Book 211