Input controller

Manufacturers of CPUs make their CPUs to be general-purpose processors, which means they shouldn’t be designed to work with just one specific type of input device (e.g. a specific make of keyboard or mouse). Instead, they need to be designed to work with anything that follows the standard protocol for that input device.

To do this, the motherboard has lots of little circuits called input controllers that are designed to work with specific types of input devices. For example, there will be a keyboard controller that is designed to work with any keyboard that follows the standard keyboard protocol, and a mouse controller which does the same for mice. These controllers are connected to the processor via the buses, so the processor can receive input from the input devices and only have to understand one way of communicating with them.

An input controller is a circuit which processes the input from a specific type of input device, and sends it to the processor in a standard way that the processor can understand.