What is output port in microcontroller or microprocessor? All Questions › Category: Automotive Electronics › What is output port in microcontroller or microprocessor? 0 Vote Up Vote Down chetan shidling asked 5 years ago I need short information. 1 Answers 0 Vote Up Vote Down chetan shidling answered 5 years ago The output port is used to send binary signals to external peripherals. Example: Output to a circuit that will control the switching of the ignition coil in ignition system.