Is CPU an input device

Answer 1

No not really, it's the brain.

CPU is the Central processing Unit which receives input via input devices like keyboard, mouse , scanner, mic etc. It's main job is to process the input and send to the relevant o/p device.

It controls the flow and process of instructions, in time with a clock pulse.

It needs to handle both input and output of binary data.

Answer 2

microprocessor can be input device.... the output port can be given as input to other machine.
recall church-turing hypothesis... in that we give one turing machine as a input to other turing machine.. here, turing machine is abstracting of microprocessor

Answer 3

output device