Microprocessors & Microcontrollers: Interrupt controller 8259; The 8259 is known as the Programmable Interrupt Controller (PIC) microprocessor. In 8085 and 8086 there are five hardware interrupts and two hardware interrupts respectively. Bu adding 8259, we can increase the interrupt handling capability. This chip combines the multi-interrupt input source to single interrupt output. This provides 8-interrupts from IR0 to IR7. Let us see some features of this microprocessor.
This chip is designed for 8085 and 8086.
It can be programmed either in edge triggered, or in level triggered mode
We can mask individual bits of Interrupt Request Register.
By cascading 8259 chips, we can increase interrupts up to 64 interrupt lines
Clock cycle is not needed.
8259 microprocessor can be programmed according to given interrupts condition and it can be provided either with level or edge-triggered interrupt level.
It can be programmed to either work in 8085 or in 8086 microprocessors.
Individual interrupt bits can be masked.
By cascading Nine 8259’s in Master-Slave Configuration we can handle up to 64 interrupt pins.
It contains 3 registers commonly known as ISR, IRR, IMR & there is 1 priority resolver (PR).
Interrupt Request Register (IRR): It stores those bits which are requested for their interrupt services.
Interrupt Service Register (ISR): It stores the interrupt levels which is currently being served.
Interrupt Mask Register (IMR): It stores interrupt levels that have to be masked. These interrupt levels are already accepted by the 8259 microprocessor.
Priority Resolver (PR): It examines all the 3 registers and sets the priority of interrupts and sets the interrupt levels in ISR which has the highest priority and the rest of the interrupt bit is IRR which is already accepted.
SP/EN (low active pin): If its value is 1 it works in master mode & if its value=e is 0 then it works in slave mode.
Cascade Buffer: It is used to cascade more number of Programmable Interrupt Controller to increase the interrupts handling capability up to 64 levels.
Advantages:
Interrupt management: The 8259 microprocessor is a specialized chip that is dedicated to managing interrupts, which can help to improve system performance and reduce the workload on the main CPU.
Programmability: The 8259 microprocessor is programmable, which means that it can be customized to handle specific types of interrupts and to prioritize different interrupt requests.
Compatibility: The 8259 microprocessor is compatible with a wide range of microprocessors, making it a popular choice for interrupt management in many different systems.
Multiple interrupt inputs: The 8259 microprocessor can handle multiple interrupt inputs, which makes it a useful peripheral for managing complex systems with multiple devices.
Ease of use: The 8259 microprocessor includes simple interface pins and registers, making it relatively easy to use and program.
found this one in one of my abandoned folders. AC(students from JUCSE need no introduction but for others you should never want to know him :-O) assigned this task to me and 3 of my fellow classmates to create a presentation on this uninteresting and weird topic. We pulled it off however :P
PIC A special purpose integrated circuit that function as an overall manager in an interrupt driven system.
It accepts request from the peripheral equipment,determines which of the incoming request is of the highest priority, ascertains whether the incoming request has a higher priority value than the level currently being serviced, and issues an interrupt to the CPU based on this determination.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
found this one in one of my abandoned folders. AC(students from JUCSE need no introduction but for others you should never want to know him :-O) assigned this task to me and 3 of my fellow classmates to create a presentation on this uninteresting and weird topic. We pulled it off however :P
PIC A special purpose integrated circuit that function as an overall manager in an interrupt driven system.
It accepts request from the peripheral equipment,determines which of the incoming request is of the highest priority, ascertains whether the incoming request has a higher priority value than the level currently being serviced, and issues an interrupt to the CPU based on this determination.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Q.1 A single plate clutch with both sides of the plate effective is required to transmit 25 kW at 1600 r.p.m. The outer diameter of the plate is limited to 300 mm and the intensity of pressure between the plates not to exceed 0.07N / m * m ^ 2 Assuming uniform wear and coefficient of friction 0.3, find the inner diameter of the plates and the axial force necessary to engage the clutch.
Q.2 A multiple disc clutch has radial width of the friction material as 1/5th of the maximum radius. The coefficient of friction is 0.25. Find the total number of discs required to transmit 60 kW at 3000 r.p.m. The maximum diameter of the clutch is 250 mm and the axial force is limited to 600 N. Also find the mean unit pressure on each contact surface.
Q.3 A cone clutch is to be designed to transmit 7.5 kW at 900 r.p.m. The cone has a face angle of 12°. The width of the face is half of the mean radius and the normal pressure between the contact faces is not to exceed 0.09 N/mm². Assuming uniform wear and the coefficient of friction between the contact faces as 0.2, find the main dimensions of the clutch and the axial force required to engage the clutch.
Q.4 A cone clutch is mounted on a shaft which transmits power at 225 r.p.m. The small diameter of the cone is 230 mm, the cone face is 50 mm and the cone face makes an angle of 15 deg with the horizontal. Determine the axial force necessary to engage the clutch to transmit 4.5 kW if the coefficient of friction of the contact surfaces is 0.25. What is the maximum pressure on the contact surfaces assuming uniform wear?
Q.5 A soft surface cone clutch transmits a torque of 200 N-m at 1250 r.p.m. The larger diameter of the clutch is 350 mm. The cone pitch angle is 7.5 deg and the face width is 65 mm. If the coefficient of friction is 0.2. find:
1. the axial force required to transmit the torque:
2. the axial force required to engage the clutch;
3. the average normal pressure on the contact surfaces when the maximum torque is being transmitted; and
4. the maximum normal pressure assuming uniform wear.
Q.6 A single block brake, as shown in Fig. 1. has the drum diameter 250 mm. The angle of contact is 90° and the coefficient of friction between the drum and the lining is 0.35. If the torque transmitted by the brake is 70 N-m, find the force P required to operate the brake. Q.7 The layout and dimensions of a double shoe brake is shown in Fig. 2. The diameter of the
brake drum is 300 mm and the contact angle for each shoe is 90°. If the coefficient of friction for the brake lining and the drum is 0.4, find the spring force necessary to transmit a torque of 30 N-m. Also determine the width of the brake shoes, if the bearing pressure on the lining material is not to exceed 0.28N / m * m ^ 2
A CASE STUDY ON ONLINE TICKET BOOKING SYSTEM PROJECT.pdfKamal Acharya
Online movie ticket booking system for movies is a web-based program. This application allows users to purchase cinema tickets over the portal. To buy tickets, people must first register or log in. This website's backend is PHP and JavaScript, and the front end is HTML and CSS. All phases of the software development life cycle are efficiently managed in order to design and implement software. On the website, there are two panels: one for administrators and one for customers/users. The admin has the ability to add cinemas, movies, delete, halt execution, and add screens, among other things. The website is simple to navigate and appealing, saving the end user time.
This is a assigned group presentation given by my Computer Science course teacher at Green University of Bangladesh, Bangladesh.
My Presentation Topic was - Cloud Computing
This group presentation includes the work Md. Shahidul Islam Prodhan, pages no 10 - 15.
www.facebook.com/TheShahidul
www.twitter.com/TheShahidul
www.linkedin.com/TheShahidul
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
This document is by explosives industry in which document discussed manufacturing process and flow charts details by nitric acid and sulfuric acid and tetra benzene and step by step details of explosive industry explosives industry is produced raw materials and manufacture it by manufacturing process
Top 13 Famous Civil Engineering Scientistgettygaming1
List of Best Scientist Who Gives Big Contribution in Civil Engineering Filed, in this we provide how they Contribute in Civil Engineering filed, For Data Collection civilthings.com helps us a lot.
A case study of cinema management system project report..pdfKamal Acharya
A computer reservation system or central reservation system is a computerized system used to store and retrieve information and conduct transactions related to air travel, hotels, car rental, or activities. These systems typically allow users to book hotel rooms, rental cars, airline tickets as well as activities and tours. They also provide access to railway reservations and bus reservations in some markets, although these are not always integrated with the main system. For these systems to be accessible on mobile phones and computers outside the premises of the airport, cinema, train station or stadiums, they need to be on the internet or a network.
This project focuses on the design and implementation of a web based cinema management system for the allocation of seat tickets online. The system would feature the registration of users, use of serial numbers and pins gotten from scratch cards sold and a printed slip. The system would have a store of all the seats and automate the generation of fresh serial numbers and pins.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
2. INTEL 8259
• Intel 8259 is a Programmable Interrupt
Controller (PIC).
• There are 5 hardware interrupts and 2
hardware interrupts in Intel 8085 and Intel
8086 microprocessors respectively. But by
connecting Intel 8259 with these
microprocessors, we can increase their
interrupt handling capability.
• This chip combines the multi-interrupt input
source to single interrupt output. This
provides 8-interrupts from IR0 to IR7.
INTERRUPT
CONTROLLER
8259
2
3. FEATURES OF INTEL
8259 PIC
INTERRUPT
CONTROLLER
8259
3
• Intel 8259 is designed for Intel 8085 and Intel 8086
microprocessor.
• It can be programmed either in level triggered or in edge triggered
interrupt level.
• We can mask individual bits of interrupt request register.
• We can increase interrupt handling capability upto 64 interrupt
level by cascading further 8259 PICs.
• Clock cycle is not required.
6. ABOUT EACH BLOCK
Block : Description
Data Bus Buffer
:
This block is used to communicate between 8259 and 8085/8086 by acting as buffer. It
takes the control word from 8085/8086 and send it to the 8259. It can send maximum 8-bit
at a time.
R/W Control
Logic :
This block works when the value of pin CS is 0. This block is used to flow the data
depending upon the inputs of read(RD) and write(WR).
Control Logic : It controls the functionality of each block. It has pin called INTR. This is connected to other
microprocessors for taking the interrupt request. The INT pin is used to give the output.
Interrupt
Request
Register :
It stores all interrupt level that are requesting for interrupt service.
Cascade Buffer : To increase number of interrupt pin, we can cascade more number of pins, by using
cascade buffer. When we are going to increase the interrupt capability, CSA lines are used
to control multiple interrupts.
Interrupt Mask
Register :
It stores interrupt level that will be masked, by storing the masking bits of interrupt level.
Priority Resolver
:
It checks all three registers, and set the priority of the interrupts. Interrupt with the highest
priority is set in the ISR register. It also reset the interrupt level which is already been
serviced in the IRR.
INTERRUPT
CONTROLLER
8259
6
7. OPERATION MODE OF 8259:
1. Fully nested mode : It is the default mode of operation of 8259. Here, IR0 has the highest priority and IR7 has the
lowest priority. When any interrupt requests occurs then the highest priority interrupt request is serviced first and
its vector address is placed on data bus and its corresponding bit in ISR register is set until the processor
executes the EOI command before returning the interrupt service routine until the falling of the last INTA’. When
the ISR bit is set for an interrupt, then all the equal and lower priority interrupts are masked, but a higher level
interrupt request can occur and which will be acknowledged only if the microprocessor interrupt enables flag IF=
1. It is suitable for a single 8259 configuration.
2. Special fully nested mode (SFNM) : This mode is used by master 8259 in a cascaded mode. Its priority
structure is fixed and is the same as fully nested mode (i.e. IR0 has the highest priority and IR7 has the lowest
priority). In a special fully nested mode, the master will only serve higher priority interrupt from a slave, whose
another interrupt is currently in service.
3. Special mask mode(SMM) : In SMM, 8259 enables interrupts of all levels (lower or higher) except the one that is
currently in service. Because we are especially masking the request of the priority level of interrupt, which is the
same as the current interrupt priority level, therefore it is called special mask mode.
4. Poll mode :
Here the INT pin of 8259 is not used, so, 8259 cannot interrupt the µp. Instead, the µP will provide a poll
command to 8259 using OCW3. In response, 8259 provides a poll word to the µP. The poll word indicates the
highest priority interrupt which needs service from µP. Thereafter, the µP services the interrupt.
INTERRUPT CONTROLLER 8259
INTERRUPT CONTROLLER 8259 7
8. 5. EOI – (End Of Interrupt) : When the microprocessor acknowledges an interrupt
request by sending the first INTA signal, the 8259 sets the corresponding bit in
the In
Service Register (ISR). This starts the service of the interrupt. When this bit in
the ISR is
cleared, then it is known as the end of interrupt (EOI).
EOI Modes:
1. Normal EOI Mode – Here, an EOI command is compulsory. The EOI
command is
written by the programmer at the end of the ISR. It makes 8259 to reset the bit
from
ISR. Further EOI command is of two types :
i) Non Specific EOI Command : Here the programmer doesn’t specify the
bit
number to be reset in the ISR. 8259 itself resets the highest priority bit
from
ISR.
ii) Specific EOI Command : Here the programmer determines the bit
number
to be reset from ISR.
2. Automatic EOI mode (AEOI) – In this mode, the EOI command is not
required.
Instead, 8259 will itself clear the corresponding bit from ISR at the end of the
2nd
8
INTERRUPT
CONTROLLER
8259
10. THE INTEL 8259A IS INDEED A REVISED
VERSION OF THE ORIGINAL INTEL 8259
PROGRAMMABLE INTERRUPT
CONTROLLER (PIC). THE 8259A WAS
INTRODUCED TO ADDRESS SOME
LIMITATIONS AND IMPROVE UPON THE
FUNCTIONALITY OF THE ORIGINAL 8259.
• The 8259A is a programmable interrupt controller (PIC) that
works with Intel microprocessors 8085, 8086, and 8088.
• The 8259 works with 8-bit processors, while the 8259A works
with 8-bit and 16-bit processors.
INTERRUPT
CONTROLLER
8259
10
11. HOW IS 8259A
DIFFERENT FROM 8259
• Improved cascade support for handling
more interrupts.
• Refined initialization process for more
setup.
• Maintains compatibility with 8259.
• May perform improved performance and
reliability.
INTERRUPT
CONTROLLER
8259
11