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. Here you can download the free lecture notes of microprocessor and interfacing pdf notes mpi notes pdf materials with multiple file links to download. The individual ports can be programmed to be input or output. Tugas makalah mata kuliah arsitektur komputer di kampus sttpln jakarta. Interfacing 8086 with 8255 pdf intel a programmable peripheral interface learn microprocessor in simple sets, interrupts, addressing modes, multiprocessor configuration. The mode in which the 8255 works defines the functioning of it in that mode.
Lokanath reddy 2 8086 memory and digital interfacing 8086 addressing and address decoding interfacing ram, rom, eprom to 8086 8255 programmable peripheral interface. Electrodiction offers a complete channel of guidance on topics such as analog electronics, microprocessors, digital electronics and circuit theory. The 82c55a is pin compatible with the nmos 8255a and 8255a5. It is a tristate 8bit buffer, which is used to interface the microprocessor to the system data bus.
Ppi 8255 interface with 8085 datasheet, cross reference, circuit and application notes in pdf format. Multiple choice questions and answers mcq on the 8255 programmable peripheral interface ppi with 4 choices, correct answer and explanation. Programmable peripheral interface the 8255a is a general purpose programmable io device designed for use with intel microprocessors. This mode affects only one bit of port c at a time because, as user set the bit, it remains set until. The 8255 has 24 io pins divided into 3 groups of 8 pins each. Suresh bojja department of ece 8255 ppi programmable peripheral interface open box education. The i8255 was also used with the intel 8085 and intel 8086 and their descendants and found wide applicability in digital. The parallel inputoutput port chip 8255 is also called as programmable peripheral input output port.
Here we will see the control word format for 8255a ppi ic. Its function is that of a general purpose io component to interface peripheral equipment to the microcomputer system bus. The 8255 is a member of the mcs85 family of chips, designed by intel for use with their 8085 and 8086 microprocessors and. Adc interfacing with 8085 ppi 8255 8155 intel microprocessor block diagram. A, b, and c the individual ports can be programmed to be input or output. 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. We already discussed in my previous post about programmable peripheral interface ppi ic 8255 and operational modes of 8255 ppi ic.
In most of the cases, the pio 8255 is used for interfacing the analog to digital converters with microprocessor. As we know programmable peripheral interface ppi ic 8255 is used to interface input and output device with microprocessor. Architecture, pin diagram, operational modes and control word format. Microprocessor and interfacing notes pdf mpi pdf notes book starts with the topics vector interrupt table, timing diagram, interrupt structure of 8086. What is 8255 programmable peripheral interface ppi. We have already studied 8255 interfacing with 8086 as an io port, in previous section. Part, manufacturer, description, pdf, samples, ordering.
Modes of operation of 8255 ppi programmable peripheral. Show the control word format for io mode operation of ppi 8255. Programmable peripheral interface 8255 ppi 8255 is a general purpose programmable io device designed to interface the cpu with its outside world such as adc, dac, keyboard etc. It is a general purpose programmable io device which may be used with many different microprocessors.
Bsr mode bit set reset mode io mode inputoutput mode. Reset out signal from 8085 is connected to the reset signal of the 8255. The groups are denoted by port a, port b and port c respectively. The mode format for io as shown in figure the control word for both mode is same. Its function is that of a general purposes io component to interface peripheral equipment to the microcomputer system bush. View notes interfacing 8255 with 8051 from electrical ee1234 at engineering college. The 82c55a is a programmable peripheral interface device designed for use in intel microcomputer systems. It is also called as programmable peripheral inputoutput port. The separated address lines a0a7 are connected to a0a7 input pins of 8255 and the separated data bus d0d7 are connected to d0d7 pins of 8255. It is used to interface to the keyboard and a parallel printer port in pcs usually as part of an integrated chipset. Control word format for 8255a electronics engineering. Programmable peripheral interface 8255 geeksforgeeks. The 82c55a is a high performance cmos version of the industry standard 8255a.
It consists of three 8bit bidirectional io ports 24io lines that can be configured to meet different system io needs. Lower order of 8bit address a0a7 is separated from ad0ad7 using address latchbuffer ex. Data is transmitted or received by the buffer as per the instructions by the cpu. We can program it according to the given condition. Intel programmable peripheal interface,alldatasheet, datasheet, datasheet search site for electronic. Ppi 8255 is a general purpose programmable io device designed to interface the cpu with its outside world such as. This section we will only emphasize the interfacing techniques of analog to digital converters with 8255.
These ports are further divided in to two groups a and b. The 8255a is a general purpose programmable io device designed for use with intel microprocessors. The 8255a programmable peripheral interface ppi implements a general. Cmos programmable peripheral interface datasheet the 82c55a is a high performance cmos version of the industry standard 8255a and is manufactured using a selfaligned silicon gate cmos process scaled saji iv. Singlebit, 4bit, and bytewide input and output ports level sensitive inputs latched outputs strobed inputs or outputs strobed bidirectional input. Every one of the ports can be configured as either an input port or an output port. The intels 8255 is designed for use with intels 8bit, 16bit and higher capability microprocessors. The 82c55a is a programmable peripheral interface device designed for. Description the intel 82c55a is a general purpose programmable io device which may be used with many different microprocessors. The 8255 programmable peripheral interface intel has developed several peripheral controller chips designed to support the 80x86 processor family. The 8255 provides 24 parallel inputoutput lines with a variety of programmable operating modes. Microprocessor and interfacing pdf notes mpi notes pdf.
It is used with many microprocessors and microcontrollers for various purposes. Bit set reset bsr mode this mode is used to set or reset the bits of port c only, and selected when the most significant bit d7 in the control register is 0. Introduction to 8255a intel 8255a is a general purpose parallel io interface ic. Lecture 2 8255 programmable peripheral interface ppi 1 references chapter. The device has three 8bit ports port a, port b and port c. The 8255a programmable peripheral interface ppi implements a generalpurpose io. Here rd and wr signals are activated when iom signal is high, indicating io bus cycle. Now let us discuss the functional description of the pins in 8255a. They can also be changed dynamically, in contrast to. How many ports are there in 8255 and what are they. It has 24 io programmable pins like pa,pb,pc 38 pins. Here we see how can we use programmable peripheral interface ppi ic 8255 for data transfer. Interfacing 8255 with 8086 microprocessor interfacing.649 1104 392 441 606 1621 669 975 1046 833 131 1256 653 421 79 967 1445 747 1190 1383 415 1382 676 1466 537 104 544 1139 1221 121 759 1327 83 1526 416 159 714 209 1384 1495 876 982