Slide 1
Expansion Bus
Chapter 5 Expansion Bus1
Expansion Slot
Are slots that enabled hardware-add ons.
Expansion slot slots that enabled hardware-add ons2
Expansion BusA. Internal BusB. External Bus
Special set of external data bus & address bus wires in the
Northbridge for devices connected to the PCs expansion slot.
Two classification of Expansion bus: the internal and external
bus3
The Expansion bus connects to the Northbridge chip
Address Bus goes to expansion slots
Device Drivers A computer program allowing higher-level computer
programs to interact with a hardware device.
System Resources a collective term for the I/O address, IRQ
& DMA: settings that enable each device in a PC to communicate
with the CPU & request RAM space for its use.
External data bus main data path on your PC.Address bus main
communication path between the CPU and devices in your computer.
I/O address a unique pattern of ones & zeros used by the CPU to
give instructions to a device on a PC.
Binary and Hexadecimal values for four address Bus WiresBinary
NumberState of Wires (On or Off)Hexadecimal Value000000010010All
wires offOnly fourth wire onOnly third wire on0120011Third and
fourth wires on30100Only second wire on40101Second and fourth wires
on50110Second and third wires on60111Only first wire off71000Only
first wire on81001First and fourth wires
on9101010111100110111101111First and third wires onOnly second wire
offFirst and second wires onOnly third wire offOnly fourth wire
offAll wires onABCDEF
8
0000 0000 0110 00000000 0000 0110 00000000
0
0
6
0011000000000Binary NumberState of Wires (On or Off)Hexadecimal
Value000000010010All wires offOnly fourth wire onOnly third wire
on0120011Third and fourth wires on30100Only second wire
on40101Second and fourth wires on50110Second and third wires
on60111Only first wire off71000Only first wire on81001First and
fourth wires on9101010111100110111101111First and third wires
onOnly second wire offFirst and second wires onOnly third wire
offOnly fourth wire offAll wires onABCDEF
0060h
h shows its a hex value
0000 0000 0110 0001 = 0061hBinary NumberState of Wires (On or
Off)Hexadecimal Value000000010010All wires offOnly fourth wire
onOnly third wire on0120011Third and fourth wires on30100Only
second wire on40101Second and fourth wires on50110Second and third
wires on60111Only first wire off71000Only first wire on81001First
and fourth wires on9101010111100110111101111First and third wires
onOnly second wire offFirst and second wires onOnly third wire
offOnly fourth wire offAll wires onABCDEF
0000 0000 0110 0010 = 0062h0000 0000 0110 0011 = 0063h
Windows Update
Internal Buses 8-Bit ISA 16-Bit ISA MCA (Micro Channel
Architecture) EISA (Extended Industry Standard Architecture) VESA
Local Bus (VL-Bus) PCI (Peripheral Component Interconnect) AGP
(Accelerated Graphics Port) AMR (Audio Modem Riser) / CNR
(Communications/Networking Riser) Mini PCI
Internal Buses: 8-Bit ISA
~ developed by IBM.~ Industry Standard Architecture (ISA) bus
the first PC expansion bus. ~ 8 bits wide & runs at 7 Mhz.
Internal Buses: 16-Bit ISA
~ a redesigned 8-bit ISA with a small extension creating a
16-bit ISA.~ No substantial difference between, the 8-bit &
16-bit ISA slots other than their width in bits.
16-bit ISA14
Internal Buses: MCA (MicroChannel Architecture)
~ developed by IBM .~ 32 bits wire compatible for external data
bus of 386 and 486 CPUs & ran at 12 MHz, faster than ISA ~
self-configuring
Internal Buses:
EISA (Extended Industry Standard Architecture)
~ developed by Compaq and Dell in late 1980s~ 32-bits wide &
ran at 8.33 MHz ~ self-configuring
- EISA has something MCA does not have: backward
compatibility
EISA16
Internal Buses: PCI (Peripheral Component Interconnect)
~ developed by Intel. ~ self-configuring & runs at 33 MHz.~
has all the good aspects of both MCA and EISA. ~ has a mezzanine
bus feature that does not have to be the only expansion bus on the
motherboard.
17
Internal Buses: VESA Local Bus (VL-Bus)
~ VESA (Video Electronics Standards Association)~ A parasitic
bus. A local bus worked alongside the ISA bus. ~ it act as a
high-speed conduit for memory-mapped I/O and DMA, while the ISA bus
handled interrupts and port-mapped I/O.
Northbridge terminated 16 of the 32 external data bus wires
Northbridge & Southbridge connected to expansion slots
21
Northbridge, southbridge & Ich on Intel System
~ with its own personal connection to the Northbridge.
Internal Buses: AGP (Accelerated Graphics Port)
- A PCI slot.~ Only for graphics.
24
Internal Buses: AMR/CNR
~ AMR ( Audio/Modem Riser) ~ CNR (Communications/Networking
Riser) ~ a noise limiting devices. A riser expansion slot. designed
to interface with chipsets and provide analog functionality, such
as sound cards and modems, on an expansion card.
Internal Buses:
- Slot used only for laptops. Mini PCI
External Expansion Buses: USB Fire Wire
External Expansion Buses:Two versions of USB:a. USB 1.1 -
devices run at one of two speeds: a low speed of 1.5 Mbps & a
high speed of 12 Mbps.b. USB 2.0 - devices run at a blistering 480
Mbps. - Viable option for large data storage.USB 2.0 Icon
External Expansion Buses:Two different USB Connectors:a. USB A
Connectorb. USB B Connector
External Expansion Buses: Fire Wire- also known as IEEE 1394
standard- designed by apple computers
External Expansion Buses:Personal Computer Memory Card
International Association (PCMCIA) card interface
better known as PC Card. a form factor of a peripheral interface
designed for laptop computers.
External Expansion Buses:Card Types:
Type I 16 bit. Form factor thickness 3.3 mm Type II 16 bit or 32
bit. Form factor thickness 5.0 mm. Type III 16 bit or 32 bit. Form
factor thickness 10.5 mm.
