Vectored interrupt

In computer science, a vectored interrupt is a processing technique in which the interrupting device directs the processor to the appropriate interrupt service routine. This is in contrast to a polled interrupt system, in which a single interrupt service routine must determine the source of the interrupt by checking all potential interrupt sources, a slow and relatively laborious process.

Implementation

Vectored interrupts are achieved by assigning each interrupting device a unique code, typically four to eight bits in length.^[1] When a device interrupts, it sends its unique code over the data bus to the processor, telling the processor which interrupt service routine to execute.

References

1. Hamacher, Carl (2002). "INPUT/OUTPUT Organization". Computer Organization (5th ed.). McGraw Hill. p. 214. ISBN 0072320869.