What is Microprocessor 8085 Pin Configuration?

The following image depicts the pin diagram of 8085 Microprocessor −

The pins of a 8085 microprocessor can be classified into seven groups −

Address bus

A15-A8, it carries the most significant 8-bits of memory/IO address.

Data bus

AD7-AD0, it carries the least significant 8-bit address and data bus.

Control and status signals

These signals are used to identify the nature of operation. There are 3 control signal and 3 status signals.

Three control signals are RD, WR & ALE.

• RD − This signal indicates that the selected IO or memory device is to be read and is ready for accepting data available on the data bus.
• WR − This signal indicates that the data on the data bus is to be written into a selected memory or IO location.
• ALE − It is a positive going pulse generated when a new operation is started by the microprocessor. When the pulse goes high, it indicates address. When the pulse goes down it indicates data.

Three status signals are IO/M, S0 & S1.

https://www.tutorialspoint.com/index.htm