Interrupt

Interrupt is a signal to a computer system or device to stop its current operation and handle a particular condition. In computing, an interrupt is an asynchronous signal from hardware indicating the need for attention or a synchronous event in software indicating the need for a change in execution.

Overview

An interrupt alerts the processor to a high-priority condition requiring the interruption of the current code the processor is executing. The processor responds by suspending its current activities, saving its state, and executing a function called an interrupt handler (or an interrupt service routine, ISR) to deal with the event. This interruption is temporary, and, after the interrupt handler finishes, the processor resumes normal activities.

Types of Interrupts

There are several different types of interrupts, including:

• Hardware Interrupts are issued by hardware devices like disk drive and keyboard when they need to communicate with the CPU.
• Software Interrupts are issued by a program requiring disk input or output operations.
• Timer Interrupts are issued by a system timer. The system timer could be a dedicated timer on a chip or could be built into one of the system's peripheral chips.

Interrupt Handling

When an interrupt is generated, the processor saves its execution state via a context switch, and begins executing the interrupt handler at the interrupt vector.

See Also

• Interrupt Request (IRQ)
• Interrupt Handler
• Interrupt Vector
• Interrupt Request Level (IRQL)
• Interrupt Descriptor Table (IDT)

References

Interrupt Resources
Latest articles Most recent articles Ongoing trials	Wikipedia