How do interrupts work in computer architecture?

Interrupts in computer architecture are signals sent to the processor to alert it of an event that needs immediate attention.

In more detail, an interrupt is a mechanism by which an I/O or an instruction can suspend the normal sequence of processing by the processor. It's a way of controlling the execution flow of the processor. When an interrupt signal is received, the processor temporarily stops its current tasks and transfers control to a specific interrupt service routine (ISR), which is a piece of code designed to handle the conditions that caused the interrupt.

Interrupts can be triggered by both hardware and software. Hardware interrupts are typically triggered by peripheral devices such as keyboards or mice that need to send data to the processor. For example, when you press a key on your keyboard, it sends an interrupt signal to the processor to let it know that it has data to send. Software interrupts, on the other hand, are triggered by programs running on the computer. They are used to request services from the operating system such as reading a file or displaying information on the screen.

There are also different types of interrupts based on their priority. Some interrupts have a higher priority than others, meaning they will be serviced first. This is important in situations where certain tasks need to be completed immediately, such as handling a system error.

When an interrupt occurs, the processor needs to save its current state so that it can return to its task once the interrupt has been serviced. This involves saving the program counter, which keeps track of where the processor is in its current task, and other relevant information. Once the interrupt has been serviced, the processor can then restore its state and continue with its task.

In summary, interrupts are a crucial part of computer architecture. They allow the processor to respond to events as they occur, ensuring that important tasks are completed in a timely manner.