CHAPTER
Microcomputer as a
Communication Device
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
INTRODUCTION
MODULE
Overview of Communication
Components of a Microcomputer
Communication Components Of
Firewire Bus
a
Micro
Port
USB Bus Port
Expansion
Bus
Expansion Bus
Parallel
Port
Serial
Port
Built-in port
connection.
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)
Built-in serial and
parallel port connection.
ISA expansion
PCI expansion
slots.
slots.
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ISA slots – now outdated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
END OF MODULE
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
Com1
Com2
LPT1
Ports on the Back of a Computer
Combo Ports on an NIC
NIC Connection
NIC
Twisted
Pair
Cable
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
END OF MODULE
END OF MODULE
END OF CHAPTER