Interrupt

In a computer an interrupt works just like in a conversation: something happens and everything stops.

An interrupt in the computer is a signal sent to the microprocessor which stops its present operation until some other operation can get the attention it needs. The interrupt may require immediate attention or may sit in a buffer until the processor can get around to it and process it. As one example, when you press a key on the keyboard a signal is sent to the computer which generates an interrupt to tell the computer that a key has been pressed. Things stop momentarily in order to see if that key means something must happen (e.g., put a character in memory and display it on the screen as in a word processor or stop processing as when the Escape key is pressed).

Hardware interrupts are handled by a control unit within the computer which intercepts them and determines where they need to go to be handled.

Software interrupts are generated within a program and are used to tell the computer what to do next after the interrupt is sent.

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