At some times, you may notice that the main processor has stopped working and check for messages from the controller; then it tries to process the message after which it resumed work. This is referred to as polling. However, if the main processor receives an error message from the device, then there would be an interrupt request.
Polling is more or less like a protocol, where the CPU checks the device regularly if there might be a need for an action to be taken. Interrupts refer to some mechanisms that are specially organized for the communication of some devices. In the case of polling, there is only a cyclic reading of the devices that are connected to only a CPU.
The external logic circuits are being examined and thereby runs a program if there is a need for servicing. But if there is an interruption, the microcomputer would interrupt the running of current program, and then it runs the interrupted program.
R. Barnes, Professional Gamer, Graduation, Oakland
Answered Jul 22, 2020
Polling is the process by which a microcomputer checks if there is any request or message from any of its external logic circuits that need to be fixed. This is done periodically, and in the event that there is something that needs to be fixed, the microcomputer will fix it and resume operations.
On the other hand, an interrupt is like a signal that is sent to the microprocessor to fix an error that occurs during the execution of a program. To fix this, an interrupt request will be sent to inform the system subroutine to stop performing the task so that the error can be fixed.
The polling process is automatic so as to know whether an action is required. This means the polling process is controlled by the CPU. In contrast, the interruption signal usually comes from the affected devices so that the CPU can be aware of any development or if an action is required.