What is an Interrupt? Interrupt is a signal which has highest priority from hardware or software which processor should process its signal immediately. Types of Interrupts: Although interrupts have highest priority than other signals, there are many type of interrupts but basic type of interrupts are 1. Hardware Interrupts: If the signal for the processor is from external device or hardware is called hardware interrupts. Example: from keyboard we will press the key to do some action this pressing of key in keyboard will generate a signal which is given to the processor to do action, such interrupts are called hardware interrupts. Hardware interrupts can be classified into two types they are 0 Maskable Interrupt: The hardware interrupts which can be delayed when a much highest priority interrupt has occurred to the processor. 0 Non Maskable Interrupt: The hardware which cannot be delayed and should process by the processor immediately. 2. Software Interrupts: Software interrupt can also divided in to two types. They are 0 Normal Interrupts: the interrupts which are caused by the software instructions are called software instructions. 0 Exception: unplanned interrupts while executing a program is called Exception. For example: while executing a program if we got a value which should be divided by zero is called a exception. Classification of Interrupts According to Periodicity of Occurrence: 1. Periodic Interrupt: Ifthe interrupts occurred at fixed interval in timeline then that interrupts are called periodic interrupts 2. Aperiodic Interrupt: If the occurrence of interrupt cannot be predicted then that interrupt is called aperiodic interrupt. Classification of Interrupts According to the Temporal Relationship with System Clock: 1. Synchronous Interrupt: The source of interrupt is in phase to the system clock is called synchronous interrupt. In other words interrupts which are dependent on the system clock. Example: timer service that uses the system clock. 2. Asynchronous Interrupts: If the interrupts are independent or not in phase to the system clock is called asynchronous interrupt