Interrupts explicitly generated when a processor executes a designated…

Concept

An interrupt transfers processor control to an interrupt service routine after a defined trigger occurs.

In source-based terminology, device and timer events come from hardware, while executing a designated interrupt instruction generates a software interrupt synchronously.

Application

The stem fixes the trigger as execution of a designated interrupt instruction. This is an instruction-generated event, not a request from an I/O controller, timer, or power monitor.

Contrast

• An I/O interrupt originates from an input/output controller requesting service for a peripheral.

• A timer interrupt originates from a hardware timer reaching a programmed condition.

• A power-failure interrupt originates from hardware that detects an electrical supply fault.

• A software interrupt originates from execution of a designated interrupt or system-call instruction.

Result

Therefore, an interrupt explicitly generated by executing such an instruction is a software interrupt.