Skip to main content

Interrupts In Operating System

  Interrupt is the mechanism by which modules like I/O or memory may interrupt the normal processing by CPU. It may be either clicking mouse, draging cursor, printing a document etc, the case where interrupt is getting generated.

REQUIREMENT OF INTERRUPT :-
  External devices are comparatively slower thasn CPU. So if there is no interrupt, CPU would waste a lot of time waiting for external devices to match its speed with that of CPU. This decreases the efficiency of CPU. Hence, interrupt is required to eleminate these limitations.

ADVANTAGES :-
  • It increases efficiency of CPU.
  • It decreases the waiting time of CPU.
  • It stops the wastage og instruction cycle.
DISADVANTAGES :-
  CPU has to do a lot of work to handle interrupts, resume its previous execution of program.

An interrupt is a condition that halts the microprocessor temperoraily to work on different task and then return to its previous task. Interrupt is an event or signal that request to attension of CPU. This halt allows peripheral devices to access the microprocessor.

Whenever an interrupt occur the processor completes the execution of the current instruction and starts the execution of an interrupt service routine ( ISR) or Interrupt handler.

ISR is a program that tells the processor to what to do when the interrupt occurs. After the execution of ISR, control return back to main routine where it was interrupted.



Interrups are basically of two types :-
1. Hardware interrupt.
2. Software interrupt. 
  
1. Hardware interrupt :- 
   These interrupts are caused by any peripheral devices by sending a signal throush a specified pin to the microprocessor. These are two hardware interrupts in 8086 microprocessor :-

  a > NMI (Non-mascable interrupt) :- It is a single pin non-mascable hardware interrupt which cann't be disabled. It is highest priority interrupt in 8086 microprocessor.

b > INTR (Interrupt request) :- It provides a signal interrupt request and is activated by I/O port. This can be masked or delayed.


2. Software interrupt :-
     There are instructions that are inserted within the program to generate interrupts. There are 256 software interrupts in 8086 microprocesor.

   
Share, Follow and please comment if you find anything incorrect or to share more information about the topic discussed above.
        


Labels:

Comments

Post a Comment

Please comment.

Popular posts from this blog

Process Scheduling And Types of Process Schedular :-

        ⇰ PROCESS SCHEDULING Process Scheduling  is a task  of Operating System that schedules processes of different states like new, ready, waiting, terminated  and running.This scheduling helps in allocation of CPU time for each process, and Operating System allocates the CPU time for each procss. And the process scheduling plays important role to keep the CPU busy all the time.  ⏩   Followings are some objectives of Process Scheduling :-  i > To increase the amount of users within acceptable response times.  ii > To maintain the balance between response and utilization of system. iii > To decrease the enforce priorities and  give reference to the processes holding the key resources.      ⇰  PROCESS SCHEDULAR A scheduler carries out the pro cess scheduling work. Schedulers are often implemented so they keep all computer resources busy and  allows multiple users to shar...
8 comments
Read more

Process & Its state And process control block :-

                ⇰  PROCESS :- A process can be thought of as a program in execution. Means when any program is executed it becomes process. A processwill need certain resources such as CPU time , memory, files and I/O devices to complete its task. These resources are allocated to the process either when it is created or at the time of execution.             A process is the unit of work in most systems. A system consistes of a collection of processes. All these processes may execute concurrently. Traditionally a process contained only a single thread. Most modern operating ststems now supports processes that have multiple threads.         The operating system is responsible for several important works of process management as - the creation and deletion of process, the schrduling of process, communication and deadlock handling of process. Process is broudly divided into two ...
Post a Comment
Read more

Tokens and its types in 'C'

   Tokens are the smallest individual unit of a program or in simple words it is a main part of C program.Tokens are the building blocks of any program. The smallest individual and basic unit of a C programming is called c tokens.      *    Normally there are six types of tokens in C:- i> Keywords:-          Keywords are special words that are used to give a special meaning to the program and can't be used as variable and constant.They are basically a sequence of characters that have fixed to mean. For example:-                 auto     double      long     break                 float    short        char     if                while    continue   int       void etc. All...
3 comments
Read more