What is Interrupts and Interrupt Service Routines in Embedded System?

What are Interrupts or Interrupt Service Routine in Embedded Systems?

Interrupts or Interrupt Service Routines (ISRs) to embedded systems are like a referee in a football match - they take control at critical points during processing to make sure the processor does not remain stuck in a loop or take any wrong actions.

Interrupts allow an embedded system to perform various operations when certain conditions occur. This allows the processor to quickly respond to important events. Examples of interrupts are trapping an error, servicing a button press, when a counter reaches a particular value, or when the user needs to configure something on the device.

An interrupt involves two processes: the hardware and the software. When an interrupt occurs, the hardware sends an electrical signal that is interpreted by the processor as a request for privileged access. The processor then acts on the request by suspending normal program execution and transferring control to a piece of code called an Interrupt Service Routine (ISR).

The ISR is a program written by the user, responsible for dealing with the interrupt event. It might call other functions or routines, read and write registers, etc. Once the ISR completes its tasks, it transfers control back to the processor, and normal program execution resumes.

In conclusion, interrupts or interrupt service routines allow embedded applications to respond promptly to user input and any other events that need to be monitored in order to ensure a reliable system.