third part of first chapter of cam

7/30/2019 THIRD PART OF FIRST CHAPTER OF CAM

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Bus

A bus is a common pathway that carries signals between the

componentswithin

acomputer.

ThePChasahierarchyofdifferentbuses.Eachslowerbusisconnectedtothefasteroneaboveit.

Processor Bus

Featuresof

FSB

or

Processor

bus

The front side bus width is determined by bit-size.

Frequency is indicated by the FSBs megahertz (MHz) or gigahertz.

The processor bus in a modern system runs at 66MHz, 100MHz, 133MHz,200MHz, 266MHz, 400MHz, 533MHz, 800MHz, or 1066MHz and is normally 64 bits (8bytes) wide.

The processor bus operates at the same base clock rate as the CPU does

externally

The processor bus is to get information to and from the CPU at the fastest

possible speed, this bus typically operates at a rate faster than any other bus inthe system


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ISA Bus features

ISA (Industry Standard Architecture) Bus

8-bit ISA

16-bit ISA

Bus width 8 - bit

Compatible

with 8 bit ISA

Pins 62

Power +5 V, -5 V, +12 V, -12 V

Clock 4.7727266 MHz

Bus width 16 - bit

Compatible

with16 bit ISA

Pins 98

Power +5 V, -5 V, +12 V, -12 V

Clock 8.333333 MHz

8-bit ISA 16-bit ISA


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ISA -16 bit (Industry Standard Architecture) Card


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PCI (Peripheral Component Interconnect) bus

PCI Bus features

PCI is a 33 MHz fixed frequency bus architecture capable of transferringdata at a 132 MB/s High performance synchronous bus

Specification includes both 32-bit and 64-bit bus width

Maximum Data Transfer Rate (burst mode)133 MB/s for 32-bit bus clocked at 33 MHz532 MB/s for 64-bit bus clocked at 66 MHz

Another feature is PCI burst.- The address is sent, followed by a data block.- Addresses are automatically incremented by bridge and adapter.


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PCI Express

PCI-Express features

It is a serial bus that works in duplex mode

Data is transmitted in this bus through two pairs of wires called lane

Each lane is allows a maximum transfer rate of 250MB/s in eachdirection, almost twice the rate of the PCI bus

The PCI Express system having 1, 2, 4, 8, 16 and 32 lanes.

The transfer rate of PCI Express with lane 8 (x8) is 8GB/s (250x8).

It is fast enough to replace AGP and PCI.


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PCI PCIEXPRESS

Comparision between PCI & PCI Express

PCIisParallel,andassuchalldatagoesin

onedirection.

PCIExpressisaserialbasedtechnology,

datacanbesentoverthebusintwo

directionsatonce

The32bitPCIbushasamaximumspeed

of33

MHz,

which

allows

amaximum

of

133MBofdatatopassthroughthebus

persecond.

DifferentPCIExpressspecificationsallow

differentrates

of

data

transfer,

anywhere

from400MBto6400MBofdataper

secondandbeyond.

Thisbusisgeneratedbyeitherthechipset

NorthBridge

in

North/South

Bridge

chipsetsortheI/OControllerHubin

chipsetsusinghubarchitecture.

PCIExpressisadifferentialsignalingbus

thatcan

be

generated

by

either

the

North

BridgeorSouthBridge.

Highspeedperipherals,suchasSCSI

adapters,network

cards,

video

cards,

and

more,canbepluggedintoPCIbusslots.

ThemostcommonuseforPCIEXPRESSis

withgraphics

cards

which

benefits

the

hugebandwidthprovidedbytheinterface.

PCIslotsarestandardized PCIEXPRESSslotsaredependsonthe

numberoflanestheslotisintendedfor.


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AGP Bus

AGP Bus Features

It is a high-speed point-to-point channel for attaching a video card to amotherboard, primarily to assist in the acceleration of 3D computergraphics.

The AGP channel is 32 bits wide and runs at 66 MHz.

Texturing: Also called Direct Memory Execute mode, allows textures to bestored in main memory rather than video memory.

Throughput: Various levels of throughput are offered: 1X is 266 MBps, 2X is533 MBps; and 4X provides 1.07 GBps.

Sideband Addressing: Speeds up data transfers by sending commandinstructions in a separate, parallel channel

Pipelining: Enables the graphics card to send several instructions togetherinstead of sending one at a time


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PCMCIA Card Personal Computer Memory CardInternational Association.

PCMCIA Bus Features

Memory Address space The PC card supportsa 64 MB addressing capability

PCMCIA 2.1 provides for a 16-bit bus interface, has amaximum clock speed of 10 MHz and is capable of

speeds to 20 Mbps

The two most important features of PCMCIA are its Plug and Play and Hot

Swapping capabilitiesThe two most important features of PCMCIA are its Plug and Play and HotSwapping capabilities

There are three types of PCMCIA cards, all of which are rectangular and

measure 8.56 by 5.4 cm., but have different widths:Type I: up to 3.3 mm. thick, mainly used to add additional ROM or RAM.Type II: up to 5.5 mm. thick, typically used for fax/modem cards.Type III: up to 10.5 mm. thick, often used to attach portable disk drives.

third part of first chapter of cam

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