In computing

Computing

Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...

 and especially in computer hardware

Computer hardware

Personal computer hardware are component devices which are typically installed into or peripheral to a computer case to create a personal computer upon which system software is installed including a firmware interface such as a BIOS and an operating system which supports application software that...

, controller is a chip

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

, an expansion card

Expansion card

The expansion card in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.One edge of the expansion card holds the contacts that fit exactly into the slot...

, or a stand-alone device (usually called a control unit

Control unit

A control unit in general is a central part of the machinery that controls its operation, provided that a piece of machinery is complex and organized enough to contain any such unit. One domain in which the term is specifically used is the area of computer design...

) that interface

Interface

-Academic journals:* Interface: a journal for and about social movements* Interfaces * Journal of the Royal Society Interface* The Technology Interface Journal-Science:* Biointerface* Interface , boundary surface...

s with a peripheral

Peripheral

A peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....

 device. This may be a link between two parts of a computer (for example a memory controller

Memory controller

The memory controller is a digital circuit which manages the flow of data going to and from the main memory. It can be a separate chip or integrated into another chip, such as on the die of a microprocessor...

 that manages access to memory

Memory management

Memory management is the act of managing computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. This is critical to the computer system.Several...

 for the computer) or a controller on an external device that manages the operation of (and connection with) that device. A controller is usually also an adapter

Adapter (computing)

In computing, adapter is a hardware device or software component that converts transmitted data from one presentation form to another. The data presentation can be, for example, a message sent between objects in an application or a packet sent through a network.In modern personal computer, almost...

.

See also

Types of controller in computing and electronics

• Microcontroller
  Microcontroller
  A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
  
  , a computing device
• Game controller
  Game controller
  A game controller is a device used with games or entertainment systems used to control a playable character or object, or otherwise provide input in a computer game. A controller is typically connected to a game console or computer by means of a wire, cord or nowadays, by means of wireless connection...
  
  , a device used for video games
• MIDI controller
  MIDI controller
  MIDI controller is used in two senses.*In one sense, a controller is hardware or software which generates and transmits MIDI data to MIDI-enabled devices....
  
  , a device or software module used to transmit performance data to an electronic musical instrument, computer, or recording system
• Controllers specifically found in computers may include:
  • Graphics controller or video display controller
  • Memory controller
    Memory controller
    The memory controller is a digital circuit which manages the flow of data going to and from the main memory. It can be a separate chip or integrated into another chip, such as on the die of a microprocessor...
    
    , logic which manages the flow of data in a computer system
  • Disk array controller
    Disk array controller
    A disk array controller is a device which manages the physical disk drives and presents them to the computer as logical units. It almost always implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache.A disk array controller name is...
    
    , also known as RAID controller, a type of storage controller
  • Disk controller
    Disk controller
    The disk controller is the circuit which enables the CPU to communicate with a hard disk, floppy disk or other kind of disk drive.Early disk controllers were identified by their storage methods and data encoding. They were typically implemented on a separate controller card...
    
    , integrated into modern disk drive
    Disk storage
    Disk storage or disc storage is a general category of storage mechanisms, in which data are digitally recorded by various electronic, magnetic, optical, or mechanical methods on a surface layer deposited of one or more planar, round and rotating disks...
    
    s, it interfaces between the read-write head of any disk drive and the computer's peripheral bus
    • Floppy disk controller
      Floppy disk controller
      A floppy disk controller is a special-purpose chip and associated disk controller circuitry that directs and controls reading from and writing to a computer's floppy disk drive . This article contains concepts common to FDCs based on the NEC µPD765 and Intel 8072A or 82072A and their descendants,...
      
      , a specific disk controller for floppy drives
  • Flash controller or SSD controller, manages flash memory and interfaces with the host computer
  • SCSI
    SCSI
    Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
    
     controller, more properly called SCSI host bus adapter
  • Network interface controller (NIC)
  • Keyboard controller
    Keyboard controller (computing)
    In computing, a keyboard controller is a device which interfaces a keyboard to a computer. Its main function is to inform the computer when a key is pressed or released...
    
    
  • Programmable Interrupt Controller
    Programmable Interrupt Controller
    In computing, a programmable interrupt controller is a device that is used to combine several sources of interrupt onto one or more CPU lines, while allowing priority levels to be assigned to its interrupt outputs. When the device has multiple interrupt outputs to assert, it will assert them in...
    
    
  • Terminal Access Controller
    Terminal Access Controller
    A Terminal Access Controller is a host computer that accepts terminal connections, usually from dial-up lines, and that allows the user to invoke Internet remote log-on procedures, such as Telnet....
    
    , a host computer that accepts terminal connections such as remote log-ons.

Chips that may act as controllers

• Northbridge (computing)
  Northbridge (computing)
  The northbridge has historically been one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Increasingly these functions have migrated to the CPU chip itself, beginning with memory and graphics controllers. For Intel Sandy Bridge and AMD Fusion...
  
   – the name of a common type of memory controller in computing
• Southbridge (computing)
  Southbridge (computing)
  The southbridge is one of the two chips in the core logic chipset on a personal computer motherboard, the other being the northbridge. The southbridge typically implements the slower capabilities of the motherboard in a northbridge/southbridge chipset computer architecture. In Intel chipset...
  
   – the name of a common type of I/O
  I/O
  I/O may refer to:* Input/output, a system of communication for information processing systems* Input-output model, an economic model of flow prediction between sectors...
  
   controller in computing

Other articles

• Adapter (computing)
  Adapter (computing)
  In computing, adapter is a hardware device or software component that converts transmitted data from one presentation form to another. The data presentation can be, for example, a message sent between objects in an application or a packet sent through a network.In modern personal computer, almost...
  
  
• Programmable logic controller
  Programmable logic controller
  A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
  
  
• Computer bus
  Computer bus
  In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or between computers.Early computer buses were literally parallel electrical wires with multiple connections, but the term is now used for any physical arrangement that provides the same...
  
  
• Super I/O
  Super I/O
  Super I/O is a class of I/O controller integrated circuits that began to be used on personal computer motherboards in the late 1980s, originally as add-in cards, later embedded on the motherboards. A super I/O chip combines interfaces for a variety of low-bandwidth devices...
  
  

External links

• Controller description at Webopedia, a computer term dictionary.