Question: What Is An ISR?

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Interrupt handler

What is meant by ISR?

ISR. Stands for “Interrupt Service Routine.” An ISR (also called an interrupt handler) is a software process invoked by an interrupt request from a hardware device. For example, if you press and hold the right arrow key in a text file, the ISR will signal to the CPU that the right arrow key is depressed.

What is ISR in embedded system?

Interrupt Service Routines (ISR) are the portions of the program code that handle the interrupt requests. When an Interrupt is triggered (either a hardware or software interrupt), the processor breaks away from the current task, moves the instruction pointer to the ISR, and then continues operation.

How ISR is serviced?

An interrupt service routine (ISR) is a software routine that hardware invokes in response to an interrupt. ISR examines an interrupt and determines how to handle it executes the handling, and then returns a logical interrupt value. If no further handling is required the ISR notifies the kernel with a return value.

Can ISR be interrupted?

Normally, an interrupt service routine proceeds until it is complete without being interrupted itself in most of the systems. If you set the interrupt enable flag within the current interrupt as well, then you can allow further interrupts that are higher priority than the one being executed.