Motherboards

1
Motherboards

• The motherboard is the data and power
  infrastructure for the entire computer.
• Multiple-lane highways of various widths
  transport data between the components
• Called ?
• They make it easy to add new features to a
  machine to enhance performance

2
Form Factors

• The form factor is essentially the size, shape
  and design of the actual motherboard
• what sorts of cases and power supplies it can
  use, and its physical organization
• Contains pre-soldered/installed components such
  as chip set and BIOS

3
Chip Set

• Chip Set controls data transfers between
• ?
• ?
• ?
• ?
• And is one of the most critical issues in PC speed

4
Controller Chips

• Another set of chips called controller chips
  handle communication with directly connected
  peripherals such as
• ?
• ?
• There is also a super I/O chip which handles
  indirectly connected peripherals such as
• ?
• ?
• ?

5
BIOS

• Stands for ?
• most important role is to ?
• usually stored on a Flash memory chip
• Can be more than 1 BIOS (e.g. on SCSI cards,
  video cards etc.)
• Main one on motherboard

6
Functions of BIOS

• Check the CMOS setup for custom settings
• CMOS - a tiny (64 bytes) amount of RAM located on
  a ?
• Load the interrupt handlers and device drivers
• Initialise registers and power management

7
Functions of BIOS contd.

• Perform the power-on self-test called
• ?
• Display system settings
• Determine which devices are bootable
• Initiate the bootstrap sequence

8
Configuring BIOS

• System Time/Date ?
• Boot Sequence ?
• Plug and Play ?
• Mouse/Keyboard ?

9
Configuring BIOS contd.

• Drive Configuration ?
• Security ?
• Power Management ?
• Exit ?

10
System Buses

• the processor, cache, memory, expansion cards and
  storage devices, talk to each other over one or
  more "buses".
• A bus is a ?
• over which ?
• different buses for different uses

11
Bus Hierarchy

• Modern PCs have at least four buses
• The Processor Bus?
• The Memory Bus ?

12
Bus Hierarchy contd.

• The Local I/O Bus ?
• The Standard I/O Bus ?

13
Bus Properties

• Width - ?
• Speed - ?
• Bandwidth ?

14
Accelerated Graphics Port (AGP)

• Developed due to demand for more memory to
  process graphics
• Video card memory expensive compared to RAM
  limited expansion, dedicated for video only
• AGP shares main memory and releases it when not
  needed

15
Accelerated Graphics Port contd.

• considered a port (not a bus) since it only
  involves two devices - the processor and video
  card
• reduces contention over I/O bandwidth with PCI
  bus and improves PCI devices bandwidth
• not expandable

16
Peripheral Component Interconnect Express

• PCIe
• replaces the older PCI, PCI-X and AGP
• motherboard-level interconnect (links
  motherboard-mounted peripherals)
• and as an expansion card interface
• based on point-to-point serial links, rather than
  a shared parallel bus architecture.

17
PCIe

• Point to point serial bus PCI replacement
• Lane - Tx/Rx pair of full duplex serial lines
• Slots use 1 to 32 lanes compatible with PCI
• Capacity Per lane
• PCIe v1.x ?
• PCIe v2.0 ?
• PCIe v3.0 ?

18
Schematic View
Northbridge?
?
?
?
?
Southbridge?
19
Comparison of Bus Speeds