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What happens when an interrupt occurs while a process is running?
When an interrupt occurs, it causes the CPU to stop executing the current program. The control then passes to a special piece of code called an Interrupt Handler or Interrupt Service Routine. The interrupt handler will process the interrupt and resume the interrupted program.
What happens when there is an interrupt within an interrupt?
If an event occurs in an interrupt enabled source, an associated read-only status flag is set, but the CPU does not respond unless these two conditions are both met. The global interrupt mask (I bit) in the CCR is initially set after reset. It screens all maskable interrupt sources.
What causes an interrupt to happen?
Software interrupts A software interrupt may be intentionally caused by executing a special instruction which, by design, invokes an interrupt when executed. Software interrupts may also be unexpectedly triggered by program execution errors. These interrupts typically are called traps or exceptions.
What happens when an interrupt occurs in a program?
Let’s start by defining what a context switch is. When an interrupt occurs, it causes the CPU to stop executing the current program. The control then passes to a special piece of code called an Interrupt Handler or Interrupt Service Routine. The interrupt handler will process the interrupt and resume the interrupted program.
What are the advantages and disadvantages of interrupts?
One of the advantages of interrupts is that they can be used to break an infinite loop, which can create memory leaks or cause a program to be unresponsive. What is an Interrupt handler? Interrupt handlers, also commonly known as Interrupt service routine (ISR), is a block of code that is associated with a specific interrupt condition.
Can a nested interrupt be set as an interrupt?
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. This “interrupt of an interrupt” is called a nested interrupt.
How is a context switch used in interrupt handling?
This happens by means of a context switch, which forms a vital part of interrupt handling. A context switch is the process of storing and restoring state (the context) of a CPU, so that execution can be resumed from the same point at a later time.