Interrupt Handler - General Sequence Followed When Interrupts Occur By An External Device

General Sequence Followed When Interrupts Occur By An External Device

  1. Interrupt request(IRQ) signal is sent by the device to the processor.
  2. If the interrupt line is enabled the following sequence of events occur in the system, else the interrupt is ignored. The processor completes its present instruction (if any) and pays attention to the IRQ.
  3. It stores the address of the next location and content of status register to the stack
  4. It informs the device that its request has been granted and in response the device de-activates its IRQ.
  5. Using some suitable technique the processor loads its program counter(PC) with address of the ISR.
  6. With return statement occurring at the end of the ISR all stored content is loaded back into the respective registers and the processor resumes its suspended program*.
  • In preemptive scheduled operating systems the processor's control is given to process scheduler instead of the interrupted process.

Read more about this topic:  Interrupt Handler

Famous quotes containing the words general, sequence, interrupts, occur, external and/or device:

    When General Motors has to go to the bathroom ten times a day, the whole country’s ready to let go. You heard of that market crash in ‘29? I predicted that.... I was nursing a director of General Motors. Kidney ailment, they said; nerves, I said. Then I asked myself, “What’s General Motors got to be nervous about?” “Overproduction,” I says. “Collapse.”
    John Michael Hayes (b. 1919)

    We have defined a story as a narrative of events arranged in their time-sequence. A plot is also a narrative of events, the emphasis falling on causality. “The king died and then the queen died” is a story. “The king died, and then the queen died of grief” is a plot. The time sequence is preserved, but the sense of causality overshadows it.
    —E.M. (Edward Morgan)

    An entertainment is something which distracts us or diverts us from the routine of daily life. It makes us for the time being forget our cares and worries; it interrupts our conscious thoughts and habits, rests our nerves and minds, though it may incidentally exhaust our bodies. Art, on the other hand, though it may divert us from the normal routine of our existence, causes us in some way or other to become conscious of that existence.
    Sir Herbert Read (1893–1968)

    Usually he has no thoughts—but as an exception to this rule sometimes nasty thoughts occur to him.
    Friedrich Nietzsche (1844–1900)

    My grief lies all within,
    And these external manners of laments
    Are merely shadows to the unseen grief
    That swells with silence in the tortured soul.
    There lies the substance.
    William Shakespeare (1564–1616)

    Johnson did not answer ...; but talking for victory and determined to be master of the field, he had recourse to the device which Goldsmith imputed to him in the witty words of one of Cibber’s comedies. “There is no arguing with Johnson; for when his pistol misses fire, he knocks you down with the butt end of it.”
    Samuel Johnson (1709–1784)