Typical uses of interrupts include the following: system timers, disks I/O, power-off signals, and traps. Other interrupts exist to transfer data bytes using UARTs or Ethernet; sense key-presses; control motors; or anything else the equipment must do.
A classic system timer generates interrupts periodically from a counter or the power-line. The interrupt handler counts the interrupts to keep time. The timer interrupt may also be used by the OS's task scheduler to reschedule the priorities of running processes. Counters are popular, but some older computers used the power line frequency instead, because power companies in most Western countries control the power-line frequency with a very accurate atomic clock.
A disk interrupt signals the completion of a data transfer from or to the disk peripheral. A process waiting to read or write a file starts up again.
A power-off interrupt predicts or requests a loss of power. It allows the computer equipment to perform an orderly shut-down.
Interrupts are also used in typeahead features for buffering events like keystrokes.
Read more about this topic: Interrupt
Famous quotes containing the word typical:
“Sinclair Lewis is the perfect example of the false sense of time of the newspaper world.... [ellipsis in source] He was always dominated by an artificial time when he wrote Main Street.... He did not create actual human beings at any time. That is what makes it newspaper. Sinclair Lewis is the typical newspaperman and everything he says is newspaper. The difference between a thinker and a newspaperman is that a thinker enters right into things, a newspaperman is superficial.”
—Gertrude Stein (18741946)
“The books may say that nine-month-olds crawl, say their first words, and are afraid of strangers. Your exuberantly concrete and special nine-month-old hasnt read them. She may be walking already, not saying a word and smiling gleefully at every stranger she sees. . . . You can support her best by helping her learn what shes trying to learn, not what the books say a typical child ought to be learning.”
—Amy Laura Dombro (20th century)