Re: hardware polling
I think I have an example of polling & hope it helps,
Suppose you r enetering a locked room.
You knock the door & keeps knocking till someone from inside opens it.
This is polling; to complete your execution you r waiting for a certain action & keeps checking on it keeping the processor idle during the checking period.
To over come this, interrupts are used instead.
While you are waiting for the condition you can do any other task or simply giving it away till the condition is true.
Regards,
Amraldo