answersLogoWhite

0


Top Answer
User Avatar
Wiki User
Answered 2008-08-17 11:51:43

When a CPU receives an Interrupt Request (IRQ), it first checks if it must react to the interrupt. So-called Maskable Interrupts allow a programmer to specify that the CPU does ignore it, while Non-Maskeable Interrupt requests must be serviced.

It is important to note that an Interrupt is a way to communicate asynchronously with the CPU - very much like sending an email.

When you send an email to a person, you cannot know at which time the person reads the message, let alone when the person reacts.

A phone call, on the other hand is synchronous (happening at the same time): when I call you, you must answer right now.

Interrupts where introduced to allow tgis email-like communication with slower hardware, like a hard-disk. This way, the CPU can order something from the HD, like "go to this location", the CPU can then return to more important stuff, while the HD seeks. When the HD is done, it sends the CPU an IRQ, which tells the CPU "I am done, talk to me".

The CPU then does a so-called contex-switch, which is a rather costly operation: it must store all the data it was working on earlier in some secure way, normally on the stack and then begin to execute the so-called Interrupt Handler, a piece of software associated with the number of the IRQ.

After executing it, it can carry on doing what it did earlier (after having loaded all the data back into its registers).

The concept of IRQs make multi-tasking possible, here, the OS interrupts each process after its time-slice has expired.

001
๐Ÿ™
0
๐Ÿคจ
0
๐Ÿ˜ฎ
0
๐Ÿ˜‚
0
User Avatar

Your Answer

Loading...

Still have questions?

Related Questions

Why DMA access to main memory is given higher priority than processor access to main memory?

In a DMA while the data is transferred between the memory and the device, if it is stopped or interrupted by any other device like CPU, it would result into a Data loss, since DMA doesnt have a program counter unlike CPU which stores it current position. In CPU if it is interrupted, it suspends it s operation without any data loss. Hence DMA has a higher priority than CPU.


What happens when a chemical change does not go through completion?

The chemical reaction is interrupted.


What happens when an electric current is interupted?

When the circuit is interrupted, the current stops flowing.


What happens to the data in the CPU?

goes into the computer's hardware.


Difference between preemptive and non preemptive system.with example?

Preemptive scheduling allows a process to be interrupted in the midst of its execution, taking the CPU away and allocating it to another process.Non-preemptive scheduling ensures that a process relinquishes control of the CPU only when it finishes with its current CPU burst.


What happens if the CPU fan fails?

The CPU will overheat (safety shutdown usually happens at around 69 degrees C), and you will be unable to use the computer for prolonged periods unless it is running with less than 50% CPU usage in a very cool environment. Side effects of constant CPU overheat can include the capacitors blowing on the motherboard if they are near the CPU heatsink.


What happens in a series circuit if a light blows?

The circuit current is interrupted and all the lights will go out.


What happens if you spray dust remover in your CPU?

It reluctantly moves and then shuts off


What is the episode when frasier is interrupted before a date by martin niles and daphne?

there are about 50 episodes that, that happens you have to explain more


What happens when CPU does not meet game requirements?

Most likely your computer will overheat and crash.


What are some antonyms for interrupted?

disturbed is a antonym for interrupted


What is CPU Protection and why is it necessary?

CPU protection is one who protect the CPU. and the one who destroy the CPU also is the one who protect the CPU and the one who destroy the CPU is the one who protect the CPU and the one who destroy the CPU is the who protect the CPU and the one who destroy the CPU is the one who protect the CPU and the one who destroy the CPU is the who protect the CPU and the one who destroy the CPU is the one who protect the CPU and the one who destroy the CPU is the one who protect the CPU.


Why was the Hanukkah interrupted?

There is no tradition of the holiday of Hanukkah being interrupted.


What is the ISBN of A House Interrupted?

The ISBN of A House Interrupted is 0060724277.


What is an interrupt in computer software?

If you are eating your lunch and the phone rings, you stop eating to answer the phone. Your lunch has been interrupted. On a computer it is about the same. The computer is busy doing a task (recalculating a spread sheet) and there is something arriving on the network for the computer. The network signals the CPU that it needs immediate attention by changing the state of the interrupt request pin (IRQ) on the CPU. This causes the CPU to stop what it is doing to attend to the network card. This is a hardware interrupt. There are also software interrupts that are a CPU instruction that a program can make use of to do things like reading or writing to a hard/floppy disk. When the CPU is dealing with a hardware interrupt it will not accept any new interrupts preventing an interrupt being interrupted. Hardware like a mouse or soundcard would often have a TSR (terminate and stay resident). The TSR would be the necessary interrupts for hardware device.


What happens when a program is running?

It consumes your memory space in primary memory and can manipulate and create files on the system. Also it is being executed by the CPU so it further consumes the CPU time


What happens to an electric current at a light switch?

When an electrical switch is in the off position, the circuit is interrupted. When the switch is on, the circuit is open and complete.


How is an array name interrupted?

for example: long int interrupted [10];


What is the duration of The Interrupted Journey?

The duration of The Interrupted Journey is 1.33 hours.


How many syllables are in the word interrupted?

There are four syllables in the word interrupted.


How many pages does A House Interrupted have?

A House Interrupted has 280 pages.


What is the duration of Interrupted Melody?

The duration of Interrupted Melody is 1.77 hours.


What is Interrupted area Projection?

well it is like a map interrupted by people and its places


When was An Interrupted Divorce created?

An Interrupted Divorce was created on 1916-08-06.


When was Girl Interrupted at her Music created?

Girl Interrupted at her Music was created in 1660.