Please give me the right answer and explain why it is correct please. I see a lo
ID: 3912918 • Letter: P
Question
Please give me the right answer and explain why it is correct please. I see a lot of different answers
Which of the following statement regarding interrupt is incorrect? (A) If no interrupts are pending, the
processor proceeds to the next fetch stage. (B) Interrupt usually involves some overhead. (C) In handling
multiple interrupts, the processor cannot disable other interrupts while an interrupt is being processed. (D)
When the processor transfers control to the interrupt service routine, it needs to save the Program Status Word
and the location of next instruction to be executed. (E) None of the above.
Explanation / Answer
A) Correct. If interrupt is pending processor would suspend execution of the current instruction of the current program. Processor sets PC to starting address of the interrupt and executes interrupthandler routine. But if there are no pending interrupts, processor will fetch next instruction of current program and executes it.
B) Correct. Interrupts have some overhead which is due to switching between the programs and saving/restoring of the machines state.
C) Incorrect. Processor can disable interrupts to provide synchronization and mutual exclusion.
D) Correct. Processor needs to save this information to resume the current program execution at the point of interrupt once ISR returns.