8255 programmable peripheral interface pdf files

The 8255 is a member of the mcs85 family of chips, designed by intel for use with their 8085 and 8086 microprocessors and. View notes 8255 ppi from bscs csc232 at comsats institute of information technology. An 8086 8255 based system is required to operate an 7segment. Three of those ports correspond to the industry st andard programmable peripheral interface ppi 8255 mode 0 only. For example, you may want to have your pc turn on a switch, or have a switch electronically activate your pc to execute a. Attachment of three to five generalpurpose io ports 8 bits each to a parallel ata interface fig. Introduction to 8255 ppi the intel 8255a is a highperformance, general purpose programmable io device is designed for use with all intel and most other microprocessors the 82c55 is a popular interfacing component, that can interface any ttlcompatible io device to. The 8255 programmable peripheral interface ppi is a versatile and easy to construct circuit card the plugs into an available slot in your ibm pc. Programmable peripheral interface the 8255a is a general purpose programmable io device designed for use with intel microprocessors. There are 24 io pins which may be individually programmed in 2 groups of 12 and used in 3 major modes of.

The 8255 programmable peripheral interface ppi it is one of the most widely used io chips. Intel, alldatasheet, datasheet, datasheet search site for electronic components. Such a card allows you to do both digital input and output dio to your pc. The 8255 provides 24 parallel inputoutput lines with a variety of programmable operating modes. Ppi 8255 is a general purpose programmable io device designed to interface the cpu with its outside world such as adc, dac, keyboard etc. The 8255a card is programmable by the sysstem software. Port a contains one 8bit output latchbuffer and one 8bit input. Microprocessor 8255 programmable peripheral interface. The mode format for io as shown in figure the control word for both mode is same. Every one of the ports can be configured as either an input port or an output port. This set of microprocessor multiple choice questions.

An 8086 8255 based system is required to drive an led connected to bit 2 of port b based on two switch inputs connected to bit 0 and 1 of port a. It has 24 inputoutput lines which may be individually programmed in two groups of twelve lines each, or three groups of eight lines. We can program it according to the given condition. Suresh bojja department of ece 8255 ppi programmable peripheral interface open box education. The various methods of data transfer from the microprocessor to output devices or viceversa has already been discussed in my earlier posts.

The device has twenty four io lines arranged as three ports a,b and c. The 8255a is a programmable peripheral interface ppi device designed for use in intel microcomputer systems. Intel 8255 from wikipedia, the free encyclopedia the intel 8255 or i8255 programmable peripheral interface ppi chip is a peripheral chip originally developed for the intel 8085 microprocessor, 1 and as such is a member of a large array of such chips, known as the mcs85 family. It is used to interface to the keyboard and a parallel printer port in pcs usually as part of an integrated chipset. Port b consists of one of 8bit data output latchbuffer and one data input buffer. Port c eight pins can be grouped into two 4bit as cuppercu and clower cl or used as individual the functions of these ports are defined by writing control word to the control register. An 80868255 based system is required to drive an led connected to bit 2 of port b based on two switch inputs connected to bit 0 and 1 of port a. Programmable peripheal interface, 8255a datasheet, 8255a circuit, 8255a data sheet. The largest number 1111 mediaportal piiptv plugin for nokia n series phones pdf 1111 ff, thus 8085. It is a tristate 8bit buffer, which is used to interface the microprocessor to the system data bus. Singlebit, 4bit, and bytewide input and output ports level sensitive inputs latched outputs strobed inputs or outputs strobed bidirectional input. Its function is that of a general purpose io component to interface peripheral equipment to the microcomputer system bus. The parallel inputoutput port chip 8255 is also known as programmable peripheral inputoutput port.

The 8255 has 24 io pins divided into 3 groups of 8 pins each. Now let us discuss the functional description of the pins in 8255a. The functional configuration of the 82c55a is programmed by the system software so that normally no external logic. The 82c55a is a programmable peripheral interface device designed for use in intel microcomputer systems. A0 a1 address inputs the logical combination of these two input lines determines which internal register of the 8255 data is written to or read from. It can be used to transfer data under various condition from simple inputoutput to interrupt inputoutput. This is economical, functional, flexible but is a little complex and general purpose io device that can be used with almost any microprocessor. It consists of three 8bit bidirectional io ports 24io lines that can be configured to meet different system io needs. The 8255 ppi ibm pc interface card programmable peripheral interface plugs into any available 8 or 16bit slot atslot on pcs motherboard. Bit d7 is used for specifying whether word loaded in to bit set. Description the intel 82c55a is a general purpose programmable io device which may be used with many different microprocessors. Programmable peripheral inputoutput port is other name for a serial inputoutput port b parallel inputoutput port c serial input port d parallel output port answer.

Intel 8255 programmable peripheral interface pins, modes and interfacing with 8088 cpu muhammad usman. The intel 8255 or i8255 programmable peripheral interface ppi chip was developed and manufactured by intel in the first half of the 1970s for the intel 8080 microprocessor. Programmable peripheral interface pdf bittorrentprinter. Interface lcd with 8051 using 8255 pia electronics. An 80868255 based system is required to operate an 7segment. Introduction to 8255 ppi the intel 8255a is a highperformance, general purpose programmable io device is designed for use with all intel and most other microprocessors the 82c55 is a popular interfacing component, that can interface any ttlcompatible io device to a microprocessor. Port a consists of one of 8bit data output latchbuffer and one data input buffer. As we know programmable peripheral interface ppi ic 8255 is used to interface input and output device with microprocessor. A, b, and c the individual ports can be programmed to be input or output.

Lecture materials on 8255 programmable peripheral interface prepared by mohammed abdul kader, lecturer, eee, iiuc if bit 7 of the control word is a logical 1 then the 8255 will be. Write an 8086 assembly language program to perform logical and operation on the led using the switches. Programmable peripheral interface ppi 8255 8255 is a general purpose programmable device used for data transfer between processor and io devices. Programmable peripheral interface 8255 linkedin slideshare. The groups are denoted by port a, port b and port c respectively. Design and simulation of 8255 programmable peripheral. It consists of three 8bit bidirectional io ports i.

Programmable peripheral interface 8255 downloads at download free pdf files,ebooks and documents lecture42 intel 8255. It has 24 io programmable pins like pa,pb,pc 38 pins. How many ports are there in 8255 and what are they. Reset the 8255 is placed into its reset state if this input line is a logical 1. The interface card contains 8253 chips and 8255 chips, the 8253 chip provides programmable interval timercounter functions and the 8255 chips provide programmable inputoutput functions. Data is transmitted or received by the buffer as per the instructions by the cpu. Requires insertion of wait states if used with a microprocessor using higher that an 8 mhz clock. Pdf the 8255a programmable peripheral interface ppi implements a generalpurpose io interface to connect peripheral equipment to a microcomputer system bus. Its function is that of a general purposes io component to interface peripheral equipment to the microcomputer system bush.