CHAPTER CHAPTER

Microcomputer as a Microcomputer as a Communication Communication

DeviceDevice

Chapter Objectives

• Examine the components of the motherboard that relate to communication

• Describe a few communication links involving the microcomputer

• Discuss the Port Settings and Port Resources

• Outline the procedure for installing and configuring a multi-port interface card

Chapter Modules

• Overview of Communication Components of a Microcomputer

• Communication Ports• Communication Device Interface• Communication Port Configuration

END OF CHAPTER END OF CHAPTER INTRODUCTIONINTRODUCTION

MODULE

Overview of Communication Components of a Microcomputer

Communication Components Of a Micro

Expansion Bus

ParallelPort

SerialPort

Built-in portconnection.

USB Bus Port

Firewire Bus Port

Expansion Bus

Port and a Bus

• Port is used for connecting only one device– Serial port, parallel port etc.

• A bus can be used for connecting multiple devices– PCI, USB, SCSI etc.

Motherboard (Main Board)

PCI expansionslots.

ISA expansionslots.

Built-in serial andparallel port connection.

Devices Connected to Communication Port or

Expansion Bus• Modem• ISDN adapter• LAN cards• Terminal emulation cards• Etc.

Older Expansion Bus Technologies

• ISA (Industry Standard Association )

• EISA (Extended Industry Standard Association)

• MCA (Micro Channel Architecture)• VESA (Video Electronic Standards

Association)

PCI: Newer Expansion Bus Technology

• PCI (Peripheral Component Interconnect)

• Developed by Intel• Found in most Intel based

microcomputers• Supports plug-and-play• Continuously being improved by

releasing new chip sets

PCI Technology

• PCI – Older versions are slower than AGP

• PCI 2.0• PCI Express

– Generally faster than AGP

Expansion Bus Width

• 8, 16, 32 and 64 bits wide• 16-bit is common with ISA technology• 32-bit is the norm with PCI technology• PCI technology also supports 64-bit bus • Most PCs have a combination of 16-bit

and 32-bit buses– 16-bit ISA slots and 32-bit PCI slots

PCI Bus Speed

• Older PCI buses operated at 33 MHz

• Newer PCI buses operate at speeds of 66 MHz, 100 MHz and 133 MHz

Sample Expansion Bus Configurations

• Four 32-bit PCI slots and four 16-bit ISA slots – now outdated

• PCI 32-bit 33 MHz• Evolving PCI 32 100 MHz or faster• Advanced microcomputers such as

those specially intended to function as fast network servers incorporate 64-bit PCI slots

Sample Expansion Bus Configurations: Past an

Future

• Past– Three 32-bit EISA slots and five 16-bit

ISA slots– Two 32-bit VESA slots, five 16-bit ISA

slots and one 8-bit ISA slot

• Current– 32-bit and 64-bit PCI slots– PCI Express technology or higher– Faster bus speeds in MHz..

PCI Bus Technology

• PCI 1.0 • PCI 2.0• PCI Express

– PCI X1, X2, X4, X8 and X16

In Summary

• Expansion bus technology plays an important role with respect to the performance of the devices attached– Important in the case of a network

interfere card– Not as critical in the case of a low

speed device such as a modem

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MODULE

Communication Ports

Communication Ports

• Serial port – The older RS-232 standard– The newer USB standard– IEEE 1394 FireWire

• Parallel port – IEEE 488 standard

• Enhanced by ECP and EPP

• Additional details can be found in modules entitled serial and parallel communications

Com and LPT Ports on a Computer

Port Holders

Com2

Com1

LPT1

Ports on the Back of a Computer

Combo Ports on an NIC

NIC Connection

Twisted PairCable

NIC

Newer Communication Ports

• USB 2.0• Firewire

Disadvantages of Legacy Ports

• Each port requires a set or resources• Each port can be connected to only

one device• In the case of newer ports, only one

set of resources are needed per USB hub– Several devices can be connected to

the hub

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