Question

Need of interrupt routines in embedded system

Answer 1

an interrupt is a signal to the processor emitted by hardware or software indicating an event that needs immediate an event that meeds immediate attention

Answer 2

An interrupt is a a signal to the processor emitted by hardware or software indicating an event that needs immediate action whenever an interrupt occurs , the controller completes the execution of the current instruction and starts the execution of Internet Service Routine (ISR) .ISR tells the processor or handler what to do when interrupt occurs The interrupt can be hardware or software.
HARDWARE INTERRUPT ::) An hardware interrupt is an electronic alerting signal sent to the processor by external device,like a disc controller or external peripheral .For example,when we press a key on the keyboard or move the mouse ,they trigger hardware interrupts which cause the processor to read the keystroke or mouse position.

SOFTWARE INTERRUPTS::)A software interrupt can be caused due to either by an exceptional condition or a special instruction in the instruction set which causes an interrupt when it is executed by the processor . For example, ic the processor 's arithmetic logic unit runs a command to divide a number by zero to cause a divide by exception thus causing the computer to abandon thd calculation or display an error message . Software interrupts instruction work similar to subroutine calls