A Level Computer Science OCR Practice Exam

What defines a signal considered as an interrupt?

1. A signal that requests for halt in operations

2. A signal that originates from clock cycles

3. A signal that indicates a need for attention from the OS

4. A signal that processes inputs from users

The correct answer is: A signal that indicates a need for attention from the OS

A signal is considered an interrupt when it indicates a need for immediate attention from the operating system or the processor. This allows the system to respond promptly to events that require urgent processing, such as hardware malfunctions, input from peripherals, or time-sensitive tasks. When an interrupt is raised, the current execution of the program is paused, and control is transferred to an interrupt handler or routine designed to manage the specific condition that triggered the interrupt. This mechanism is crucial for efficient and effective resource management within a computer system, ensuring that important tasks are prioritized and handled properly. Other definitions, while they may involve signals in some way, do not capture the essence of what makes an interrupt distinct. A request to halt operations or the origin from clock cycles does not specifically relate to immediate attention or urgent processing needs. Similarly, while processing user inputs can involve interruptions, not all inputs necessitate immediate system intervention in the manner that interrupts do.