What is ISR?

1.	What is ISR?
Answer» ISR expands to Interrupt SERVICE Routines. These are the procedures stored at a particular memory location and are called when CERTAIN interrupts occur. Interrupt refers to the signal sent to the processor that indicates there is a high-PRIORITY event that requires immediate ATTENTION. The processor suspends the normal flow of the program, executes the instructions in ISR to cater for the high priority event. POST execution of the ISR, the normal flow of the program resumes. The following diagrams represent the flow of ISR.

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