Computer Hardware - buses and chipsets
Post on 12-Apr-2017
Fundamentals of Database systems
Computer HardwareMinistry of Higher EducationBamyan UniversityComputer Science Department1Presented by : Mustafa Kamel MohammadiEmail : firstname.lastname@example.org
Buses and Chipsets
learning objective In this chapter you will learnWhat is a chip in motherboard?What chipset controllers are.How all components on the motherboard are connected through buses.Types of busesSystem busesI/O buses
Controller chips and chipsetsThe motherboards busses are regulated by a number of controllers. These are small circuits which have been designed to look after a particular job.Most of these controller functions are grouped together into a couple of large chips, which together comprise the chip set.The circuits in the chipsets give motherboards intelligence and ability to workControls the movement of data, instruction and control signals between CPU, RAM, Cashe, I/O devicesContains enough instructions to perform its functions at the very lowest levelThe more newer chipsetsHigher speedNew devices like RAM, Buses and supportPlays a major role in systems functions, feature set and speed.
North bridge and South bridgeThe two chip, chipset that contains north bridge chip and south bridge chipConnects the motherboard buses with each otherThe north bridge and south bridge are connected by a powerful bus, which sometimes is called a link channel.Share the work of managing the data traffic on the motherboard.
North bridgeController that controls the flow of Data between CPU, RAM and Video ports (AGP or PCI).Connects the most high performance devicesMay contain more circuitry than other chipsHandle a huge traffic between above componentsMay have a heat sink to control the heat.
South bridgeIncludes the controller of peripheral devices that are not the essential part of system.Physically located close to I/O ports.Connects devices with lower speed.Sends data to CPU, RAM through LINK to north bridge.8
Controller chipsA controller is typically a single chip that controls the flow of data to and from peripheral devices.Each device added to the PC that wishes to interact with the data bus requires a controller.Sometimes it is not possible to include all controllers of devices in a chipsetThere are controllers that are directly mounted to motherboard likeKeyboard controllerI/O controllerSome expansion cards like the followings have built in controller chipsSound cardsVideo cardsNetwork interface cardsIndividual controller chips come in various size and shapes
Keyboard controllerAs its name indicates; it controls keyboardControls the transfer of data from the keyboard to the PCThe keyboard controller on the motherboard interacts with a controller located inside the keyboard over a serial link.When the keyboard controller on motherboard receives data from keyboardChecks for data parityTranslates the codePlaces data in output bufferNotifies processor for further processingIt was common in older systemsNewer systems includes keyboard controller in super I/O chips
Super I/O controllerIncludes many controller functions that were previously performed by many separate chips.Combining these controllersMinimize space required for controllers in motherboardMinimize the costMajor functions of super I/O controller areControlling data transfer functions of Serial portsDriving Parallel portsSupport for floppy driveHard disk controllers circuitsKeyboard controller circuits
Other chipsOne of the fundamental design facts is that CPU work much faster than any other device.Forced designers to implement buffers that acts as interface between CPU and slower devices to match speed.Individual chips has been developed for this purpose:DMA controllerAllows devices to interact with RAM without involving CPU.CRT controllerFacilitates the display of PCBus controller chip This chip controls the flow of data on the motherboards buses13
Other chipsClock generatorControls the timing of CPU operationsUART (universal asynchronous receiver transmitter) This chip is used to send and receive synchronous serial dataMath coprocessor interfaceControls the flow of data between processor and math coprocessor14
The BusesThe busses are the nerve system of system board.The busses are the PC's expressways. They are "wires" on the circuit board, which transmit data between different components. The bus architecture of the PC is made up of the wires, connectors, and devices that move data and instructions around the PC.Connects the controllers on the motherboard, the CPU, memory , I/O ports, and expansion slots.Buses are divided into two typesSystem busI/O bus
System busSystem busConnects the CPU with RAM and maybe L2-cacheDesigned to match a specific type of CPUProcessor technology determines dimensioning of the system busalso called the local busIts speed and width depends on the type CPU installed on the system board.
I/O busesI/O bussesConnect all I/O devices with the CPU and RAM. I/O devices are those, which can receive or send data (disk drives, monitor, keyboard, etc. )A bridge connects the I/O busses with the system bus and to RAM.The I/O busses differ from the system bus in speedDifferent I/O buses has been developed through the yearsISAOlder low speed busPCINewer high speed busPCI ExpressThe most modern busUSBNewer low speed bus18
Physical characteristics of BusesThe I/O buses consists of tracks on printed circuit boards, these tracks areData tracks : moving one bit a timeAddress tracks : identify address of data to be sentOther tracks for : clock ticks, voltage, verification signalsWhen data is sent on buses, the receiver of data is identified bus addressEach device has an address numberAddress tracks contains these number that identify the receiver device21
ISA buses (Industry Standard Architecture)Since about 1984, standard bus for PC I/O functions has been named ISAStill used in all PC's to maintain backwards compatibilityISA is 16 bit wide and runs at a maximum of 8 MHz. However, it requires 2-3 clock ticks to move 16 bits of data.It only had 16 data channels
PCI (Peripheral Component Interconnect)PCI is 32 bit wide and has 33MHz clock speedHas a buffer that CPU sends data to it and lowers CPU waiting time PCI adapters can also transmit data to the buffer, regardless of whether the CPU is free to process them.Capable of transferring 132MB data per second
Plug and Play (PnP) The Plug and Play standard is part of the PCI specificationIt means that all PCI adapter cards are self-configuringdeveloped by Microsoft and IntelThe idea was to provide a system where one can simply install an adapter and it will work.The adapter has to be able to inform the I/O bus which I/O addresses and IRQs it can operate with.
PCI EXPRESSSuccessor to PCIDeveloped in 2004
ReferencesPC hardware a beginners guide by Ron gilsterPC architecture by Michael Karbo 2005Illustrated guide to PC hardware by Michael karbo 1998