Interrupts and their role in firmware

Interrupts are one of the most critical mechanisms in embedded systems, allowing microcontrollers to react to real-time events efficiently. To fully appreciate their role in firmware, it’s essential to understand what interrupts are, how they work, and the various scenarios where they prove indispensable. So, let’s dive in and explore the fascinating world of interrupts, their operation, and their practical applications.

What are interrupts?

Imagine you’re deeply engrossed in reading a book but then the doorbell rings. You momentarily stop reading, attend to the visitor, and then return to your book. Interrupts in microcontrollers work similarly. They are signals that temporarily halt the current execution of a program to allow a special routine, known as an ISR, to run. Once the ISR completes, the microcontroller resumes its previous task right where it left off.

Interrupts can be triggered by hardware events, such...