How Interrupts Work: and why they are better than polling

An interrupt is a signal that causes the CPU to alter its normal flow of instruction execution. It is a much more efficient model than polling as polling requires the CPU to check devices regardless of whether they needed to be or not. This frees CPU from waiting for events and expensive context switching and provides control for external I/O initiation.

In this video we discuss the following hardware components required to make interrupts work:
* Interrupt Lines
* Interrupt Requests
* Context
* Interrupt Vector Table (IVT)
* Interrupt Service Routines (ISR) (also known as drivers)

If you have not seen the Little Man Computer (LMC) series of videos, they explore how a computer works at it most fundamental level. You can find them here:

[yash-xxpu]

this is so helpful <3 thank you you have saved my exams

[CloseUpFootball]

Thank you for the video, I learned a lot

[erim]

Hi coding coach,

in the example that you gave for multiple interrupts, where there are interrupts that are suspended- because they are "hierarchal" is that an example of polling? I am trying understand the difference between polling and interrupts and situations where polling would be used... rather than interrupts in the CPU

Thanks :-)