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Southbridge (computing)

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	Topics Southbridge (computing) Topic Home The Southbridge, also known as the I/OInput/output In computing, Input/output, or I/O, is the collection of interfaces that different functional units of an information proce... Controller Hub in Intel systems (AMD, VIA, SiS and others usually use 'southbridge'), is a chip that implements the "slower" capabilities of the motherboardMotherboard Summary A motherboard, also known as a mainboard, system board, or logic boards on Apple Computers, and sometimes ... in a northbridge/southbridge chipset computer architecture. The southbridge can usually be distinguished from the northbridgeNorthbridge (computing) The northbridge, also known as the Memory Controller Hub, is traditionally one of the two chips in the core logic chip... by not being directly connected to the CPUCentral processing unit A central processing unit , or sometimes simply processor, is the component in a digital computer that interprets ins... . Rather, the northbridge ties the southbridge to the CPU. Overview Because the southbridge is further removed from the CPU, it is given responsibility for the slower devices on a typical microcomputerMicrocomputer Although there is no rigid definition, a microcomputer is most often taken to mean a computer with a microprocessor as its... . A particular southbridge will usually work with several different northbridges, but these two chips must be designed to work together; there is no industry-wide standard for interoperability between different core logic chipset designs. Traditionally this interface between northbridge and southbridge was simply the PCI bus, but since this created a performance bottleneck, most current chipsets use a different (often proprietary) interface with higher performance. Etymology The name is derived from drawing the architecture in the fashion of a map and was first described as such with the introduction of the PCI Local Bus Architecture into the PC platform in 1991. The authors of the PCI spec at Intel viewed the PCI local bus as being at the very center of the PC platform architecture (i.e., at the Equator). The so called Northbridge extends to the north of PCI in support of CPU, Memory/Cache and other performance critical capabilities. Likewise the Southbridge extends to the south of the PCI bus backbone and bridged to less performance critical I/O capabilities such as the disk interface, audio, etc. The CPU would be at the top of the map at due north. The CPU would be connected to the chipset via a fast bridge (the northbridgeNorthbridge (computing) The northbridge, also known as the Memory Controller Hub, is traditionally one of the two chips in the core logic chip... ) located north of other system devices as drawn. The northbridge would then be connected to the rest of the chipset via a slow bridge (the southbridge) located south of other system devices as drawn. Note that current day PC platform architecture has replaced PCI with a faster I/O backbone however the bridge naming convention remains. Functionality The functionality found on a contemporary southbridge includes: PCI busPeripheral Component Interconnect The Peripheral Component Interconnect, or PCI Standard , specifies a computer bus for attaching peripheral devices to ... . The PCI bus support includes the traditional PCI specification, but may also include support for PCI-XPCI-X PCI-X is a computer bus and expansion card standard designed to supersede PCI.... and PCI ExpressPCI Express PCI Express, PCIe, or PCI-E is an implementation of the PCI computer bus that uses existing PCI programming conc... . ISA busIndustry Standard Architecture Industry Standard Architecture is a computer bus standard for IBM compatible computers. ... or LPC BridgeFacts About Low Pin Count The Low Pin Count bus, or LPC bus, is used on IBM-compatible personal computers to connect low-bandwidth devices to th... . Though the ISA support is rarely utilized, it has interestingly managed to remain an integrated part of the modern southbridge. The LPC Bridge provides a data and control path to the Super I/OSuper I/O "Super I/O" is the name given to a class of I/O controller integrated circuits which began to be used on personal computer m... (the normal attachment for the keyboard, mouse, parallel port, serial port, IR port, and floppy controller) and FWH. SPI bus. The SPI bus is a simple serial bus mostly used for firmwareFirmware In computing, firmware is software that is embedded in a hardware device.... (e.g., BIOSBIOS BIOS, in computing, stands for Basic Input/Output System or Basic Integrated Operating System.... ) flashFlash memory Summary Flash memory is a form of non-volatile computer memory that can be electrically erased and reprogrammed.... storage access. SMBusSystem Management Bus The System Management Bus is a simple two-wire bus used for communication with low-bandwidth devices on a motherboard, espec... . The SMBus is used to communicate with other devices on the motherboard (e.g. system temperature sensors, fan controllers). DMA controllerDirect memory access Direct memory access allows certain hardware subsystems within a computer to access system memory for reading and/or writin... . The DMA controller allows ISA or LPC devices direct access to main memory without needing help from the CPU. Interrupt controllerProgrammable Interrupt Controller A Programmable Interrupt Controller is a device which allows priority levels to be assigned to its interrupt outputs.... . The interrupt controller provides a mechanism for attached devices to get attention from the CPU. IDE (SATA or PATA) controller. The IDE interface allows direct attachment of system hard drives. Real Time Clock. The real time clock provides a persistent time account. Power management. The APM or ACPI functions provide methods and signaling to allow the computer to sleep or shut down to save power. Nonvolatile BIOS memoryNonvolatile BIOS memory Non-volatile BIOS memory refers to the memory on a personal computer motherboard containing BIOS settings and sometimes the ... . The system CMOSCMOS Complementary metaloxidesemiconductor , is a major class of integrated circuits.... , assisted by battery supplemental power, creates a limited non-volatile storage area for system configuration data. AC97AC97 AC'97 is Intel Corporation's Audio "Codec" standard developed by the Intel Architecture Labs in 1997, and used mainly in mot... or Intel High Definition AudioIntel High Definition Audio Intel High Definition Audio refers to the specification released by Intel in 2004 for delivering high-definition audio that ... sound interface Baseboard Management ControllerBaseboard management controller A baseboard management controller is a specialized microcontroller embedded on the motherboard of many computers, especially... Optionally, the southbridge will also include support for EthernetEthernet Ethernet is a large and diverse family of frame-based computer networking technologies for local area networks .... , RAIDRAID In computing, the acronym RAID refers to a data storage scheme using multiple hard drives to share or replicate data among ... , USBUniversal Serial Bus Universal Serial Bus is a serial bus standard to interface devices.... , audio codecAudio codec An audio codec is a computer program that compresses/decompresses digital audio data according to a given audio file format ... , and FireWireFireWire FireWire is the name given to the external wired interface specified by the IEEE standard 1394.... . Rarely, the southbridge may also include support for the keyboard, mouse, and serial ports, but normally these devices are attached through another device referred to as the Super I/OSuper I/O "Super I/O" is the name given to a class of I/O controller integrated circuits which began to be used on personal computer m... . computer m... .