From the actions given below, what is the correct sequence of actions that take place when an interrupt occurs?
(a) Processor interrupts the currently executing program.
(b) Requested action is performed.
(c) Device is informed that its request has been recognized.
(d) Device zaises an IRQ
(e) Interrupt is enabled and interrupted program is resumed.

The correct answer is Option 1) (d), (a), (c), (b), (e).

Key Points

• Interrupt handling sequence in a computer system typically follows these steps:
  1. (d) Device raises an IRQ (Interrupt Request): The hardware device signals the CPU that it needs attention.
  2. (a) Processor interrupts the currently executing program: The CPU pauses the current task and saves the context.
  3. (c) Device is informed that its request has been recognized: The interrupt controller acknowledges the interrupt.
  4. (b) Requested action is performed: The CPU executes the corresponding interrupt service routine (ISR).
  5. (e) Interrupt is enabled and interrupted program is resumed: After completing the ISR, the CPU restores the program state and continues execution.

Additional Information

• Interrupts are essential for handling asynchronous events (e.g., I/O operations, timers).
• IRQ is a signal line used to capture the interrupt request from external or internal hardware.
• ISR (Interrupt Service Routine) is the code executed in response to the interrupt.
• Advantages of interrupts:
  • Efficient CPU utilization
  • Asynchronous event handling
  • Real-time system responsiveness