A keyboard controller is an essential device that connects your keyboard to your computer. Its main function is to notify your computer when a key is pressed or released. When you type, the keyboard controller sends a signal to the CPU, allowing it to process the information.
If your keyboard is a separate peripheral unit (like most desktop computers), the controller receives scan codes from a microcontroller integrated into the keyboard via some serial interface. The controller also controls the keyboard’s LEDs by sending data back to the keyboard via the cable.
Integrated into most computers, a keyboard controller is designed to receive an input from the keyboard and pass it on to the CPU, where it can be interpreted by the operating system. When you press a key, the keyboard controller generates an interrupt, causing the CPU to momentarily halt so it can process the signal sent by the keyboard controller.
When you press a key on your keyboard, a keyboard controller receives various bit sequences and passes the information through a lookup table, translating the data into bytes, also known as scan codes. The controller also manages other physical aspects associated with your keyboard, such as the timing of the keystroke, enabling or disabling the LEDs that indicate the status of caps lock or number lock.
The keyboard controller is responsible for sensing the keyboard matrix, debouncing switch activity, and sending key presses and releases to the computer. The term also refers to the microcontroller IC that is the central part of this system. Today’s computer keyboards are self-contained devices, external to the computer, communicate with the computer via a keyboard protocol, and have operating circuitries contained within the keyboard itself.
FAQs
What is the keyboard controller used for?
A keyboard controller connects your keyboard to your computer system, transmitting signals when keys are pressed or released. It informs the CPU to process the input, allowing you to use your keyboard as an input device to communicate with your computer.
How does the keyboard controller work?
The keyboard controller translates the various bit sequences received from the keyboard into bytes, also known as scan codes, which the CPU interprets. When you press a key, the keyboard controller generates an interrupt, causing the CPU to momentarily halt to process the signal sent by the controller.
What is the difference between keyboard and controller?
A keyboard is an external input device that allows you to enter information into your computer, while a controller is a device that connects your keyboard to your computer and transmits signals when keys are pressed and released. It manages the keyboard matrix and debounces switch activities, allowing you to use your keyboard as an input device.
Final Thoughts
Now that you know what a keyboard controller is, you understand how it works and its importance in computing. As computer technology advances, keyboard controllers will continue to be critical in our everyday use of computers.
