IO addresses

1
I/O addresses

• Identify section of shared memory
• Range of memory addresses
• Hexadecimal

2
Device ManagerI/O addresses
3
DMA channels

• DMA controller relieves CPU
• DMA channels
• Largely replaced by other techniques

4
Device ManagerDMA channels
5
Base memory addresses

• Starting memory address of BIOS extensions
• Display adapters
• SCSI controllers
• IDE controllers

6
Device ManagerBase memory
7
PC/XT bus

• 8-bit bus
• IBM PC and IBM XT
• 4.77 MHz clock speed
• 1.6 Mbps maximum data transfer rate (0.4 MBps)
• Supported IRQs 0-8
• Configured with DIP switches or jumpers

8
PC/XT card
9
DIP switches and jumpers
10
PC/AT and ISA bus

• 16-bit bus
• IBM AT, clones, 80386/486, current PCs
• 8 MHz clock speed
• 8 MBps maximum data transfer rate

11
ISA adapter
12
ISA expansion bus slot
ISA slot
13
PCI bus

• 32- or 64-bit bus
• Pentium PCs
• 33 or 66 MHz clock speed
• 133-533 MBps maximum data transfer rate
• Up to 8 functions on a single card
• Up to 5 card/slots per system
• Requires PnP

14
PCI adapter
15
PCI slots
16
PCIe

• Newer standard
• Uses serial communication
• Link
• Lanes
• x1 (by-one)
• x1, x2, x4, x8, x12, x16, and x32 bus widths
• Can up-plug
• Cant down-plug

17
Need for video buses

• Older PC designs just used expansion bus
• Graphical interfaces involve massive amounts of
  graphics data
• Specialized buses developed to be fast enough

18
VESA local bus

• 32- or 64-bit bus
• Pentium PCs
• 33 or 66 MHz clock speed
• Popular on 80486-based PCs
• Generally software configurable
• No longer used

19
VLB adapter
20
AGP adapter
Note the hook
21
AGP

• Technically a port, not a bus
• 32-bit bus
• 33 or 66 MHz clock speed
• Speed pumped to as much as 533 MHz
• DIrect Memory Execute (DIME)
• 266-2133 MBps maximum data transfer rate
• PnP configurable

22
Unit summary

• Described the primary types of buses
• Defined interrupt, IRQ, I/O address, DMA, and
  base memory address
• Described the features and functions of the PCI
  bus, and installed and configure a PCI adapter
  card
• Described the features and functions of the
  various video buses, and installed and configure
  an AGP adapter card