COA- Interrupt Handling

COA- INTERRUPT HANDLING                                                               NEC LICENCE EXAM ,PCS,TU

1.

Which of the following best describes an Interrupt in COA?
a) A signal requesting CPU to stop execution permanently
b) A signal requesting CPU to suspend current execution and handle an event
c) A signal that resets the CPU automatically
d) A command to execute multiple instructions simultaneously

Answer: b) A signal requesting CPU to suspend current execution and handle an event

2.

The routine executed in response to an interrupt is called:
a) Subroutine
b) ISR (Interrupt Service Routine)
c) DMA routine
d) Exception handler

Answer: b) ISR (Interrupt Service Routine)

3.

When an interrupt occurs, the CPU first:
a) Finishes all running programs before handling
b) Immediately executes the ISR without saving the current state
c) Saves the current Program Counter (PC) and status information
d) Ignores the request until the next clock cycle

Answer: c) Saves the current Program Counter (PC) and status information

4.

Which interrupt type has the highest priority?
a) Maskable interrupt
b) Non-Maskable interrupt
c) Software interrupt
d) Vectored interrupt

Answer: b) Non-Maskable interrupt

5.

In vectored interrupts, the ISR address is:
a) Supplied by the CPU
b) Supplied by the interrupting device
c) Always stored at memory location 0000H
d) Randomly chosen by the OS

Answer: b) Supplied by the interrupting device

6.

What happens after the execution of an ISR?
a) CPU halts execution
b) CPU returns to the interrupted program using stored PC
c) The system reboots automatically
d) ISR runs continuously in a loop

Answer: b) CPU returns to the interrupted program using stored PC

7.

Which of the following interrupts can be ignored or disabled by software?
a) Non-Maskable Interrupt (NMI)
b) Hardware Interrupt
c) Maskable Interrupt
d) Trap

Answer: c) Maskable Interrupt

8.

The process of checking multiple devices to identify the one requesting an interrupt is called:
a) Polling
b) Daisy chaining
c) Context switching
d) Pipelining

Answer: a) Polling

9.

Daisy-chaining is a method used for:
a) Instruction execution
b) Interrupt priority resolution
c) Memory allocation
d) Pipeline hazard reduction

Answer: b) Interrupt priority resolution

10.

Which register is most crucial in saving the return address during an ISR call?
a) Stack Pointer
b) Program Counter
c) Instruction Register
d) Status Register

Answer: a) Stack Pointer