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Peripherals
Peripheral or peripheral devices, also known as Input-Output devices, enable the computer to remain in contact with the external environment or expand the computer's functionality. Peripheral devices enhance the computer's capability by making it possible to enter information into a computer for storage or processing and to deliver the processed data to a user, another computer, or a device controlled by the computer. Internal peripherals are connected directly to the address, data, and control buses of the computer. External peripherals can be connected to the computer via USB or a similar connection.
The USB controller is also the peripheral device, so every external peripheral (e.g. mouse) is connected to the processor via an internal peripheral. In this book, we rather consider internal peripherals directly connected to the address, data, and control buses.
Types of peripherals
There is a variety of peripherals which can be connected to the computer. The most commonly used are:
- parallel input/output ports
- serial communication ports
- timers/counters
- analogue to digital converters
- digital to analogue converters
- interrupt controllers
- DMA controllers
- displays
- keyboards
- sensors
- actuators
