Understanding Interrupts in Computer Systems

The video explains the role of interrupts and interrupt service routines in the fetch-decode-execute cycle. It describes how interrupts signal the CPU to pause its current task to address more urgent tasks. The video details how the CPU uses a stack to save the state of the current program, execute the interrupt, and then resume the original program. It also covers nested interrupts and the priority system that ensures higher-priority tasks are addressed first. The video concludes with a key question about the causes and handling of CPU interrupts.

What is the primary function of an interrupt in a computer system?

• To execute the current program faster

• To signal the processor that it needs attention

• To improve the graphics performance

• To increase the memory capacity

In the fetch-decode-execute cycle, when is the check for new interrupts performed?

• Before decoding the instruction

• After executing the instruction

• After decoding the instruction

• Before fetching the next instruction

What is the role of the interrupt service routine (ISR)?

• To decode the current instruction

• To fetch the next instruction

• To increase the clock speed

• To execute the code for the interrupt

What happens to the program counter when an interrupt is received?

• It is saved in the cache

• It points to the address of the first instruction of the interrupt

• It is reset to zero

• It continues to the next instruction

Where are the current values held in the CPU registers saved when an interrupt occurs?

• In the register file

• In the cache

• In the hard drive

• In the stack

How does the CPU resume the original program after handling an interrupt?

• By resetting the CPU

• By clearing the cache

• By loading the saved values from the stack

• By restarting the program

What is the purpose of the stack in handling interrupts?

• To increase the processing speed

• To save the state of the CPU registers

• To store the program code

• To manage memory allocation

What happens when a higher priority interrupt occurs while another interrupt is being handled?

• The current interrupt is completed first

• Both interrupts are handled simultaneously

• The current interrupt is suspended and the higher priority interrupt is handled

• The higher priority interrupt is ignored

Why do interrupts have a higher priority than normal programs?

• To increase the memory usage

• To ensure critical tasks are handled promptly

• To save power

• To slow down the execution of normal programs

What is a real-world example of an interrupt in a computer system?

• Pressing Ctrl+Alt+Delete to open the task manager

• Typing on a keyboard

• Saving a file

• Opening a web browser