Keyboard Interfacing with 8086 Using 8255 PPI: Concepts, Circuit Diagram, Program, and Applications
Keyboard Interfacing with 8086 Using 8255
Have you ever wondered how your computer keyboard communicates with the processor? How does the processor know which key you pressed and what action to perform? In this article, we will explore the concept of keyboard interfacing with 8086 microprocessor using 8255 programmable peripheral interface (PPI). We will learn about the basics of keyboard interfacing, the components involved, the modes of operation of 8255 PPI, the circuit diagram, the program, and the advantages and applications of this technique.
Keyboard Interfacing With 8086 Using 8255 153.pdfl
Before we dive into the details of keyboard interfacing with 8086 using 8255, let us first understand some basic terms and concepts.
What is keyboard interfacing?
Keyboard interfacing is a process of connecting a keyboard to a microprocessor or a microcontroller and enabling them to exchange data. The keyboard acts as an input device that sends signals to the processor when a key is pressed or released. The processor then interprets these signals and performs the corresponding action. For example, when you press the letter 'A' on your keyboard, the keyboard sends a code to the processor that identifies the key as 'A'. The processor then displays 'A' on your screen or performs some other function depending on the program.
What is 8086 microprocessor?
The 8086 microprocessor is a 16-bit processor that was introduced by Intel in 1978. It is one of the first processors to use the x86 instruction set architecture, which is still widely used today. The 8086 microprocessor has a data bus width of 16 bits, an address bus width of 20 bits, and can operate at a clock speed of up to 10 MHz. It can execute up to two instructions per clock cycle and has a total of 229 instructions. The 8086 microprocessor can address up to 1 MB of memory and has eight general-purpose registers, four segment registers, a flag register, an instruction pointer, and a stack pointer.