Question

The following are some events that occur after a device controller issues an interrupt while process L is under execution.

(P) The processor pushes the process status of L onto the control stack.

(Q) The processor finishes the execution of the current instruction.

(R) The processor executes the interrupt service routine.

(S) The processor pops the process status of L from the control stack

(T) The processor loads the new PC value based on the interrupt.

Which one of the following is the correct order in which the events above occur?

• A. TRPQS
• B. QTPRS
• C. PTRSQ
• D. QPTRS

Answer 1

The correct option is D QPTRS

Processor required to handle the interrupt:

1. Processor finishes the execution of the current instruction.

2. Processor pushes the process status of L onto the control stack.

3. Processor loads the new PC value based on the interrupt.

4. Processor executes the interrupt service routine.

5. Processor pops the process status of "L" from the control stack.