In a vectored interrupt, which statement describes how the processor…

Concept

An interrupt vector is a value associated with an interrupt source that identifies the handler to execute.

In a vectored interrupt system, the processor receives the vector during interrupt acknowledgement and uses it to select the corresponding interrupt service routine (ISR).

Application

Here the interrupting source supplies the branch information, namely the vector, to the processor. The processor uses that vector to locate the corresponding ISR, so it does not need to poll every possible source.

Contrast

• A branch address at one fixed memory location does not carry source-specific vector information.

• A branch address taken from a processor register is a CPU-held value, not information supplied by the interrupting source.

• The catch-all statement does not apply because source-supplied branch information is explicitly listed.

Cross-check

Authoritative device-driver documentation distinguishes vectored devices by their supply of an interrupt vector during interrupt acknowledgement; polled devices do not supply one.

Therefore, the interrupting source supplies the branch information to the processor.