Information Technology Reference
In-Depth Information
(c)
It guesses the address
(d)
It checks the address with the contents of the DRAM
5.3.6
How many data bits are transferred between the processor and the second-level
cache:
(a)
16
(b)
32
(c)
64
(c)
128
5.3.7
Outline the importance of the TXC (system controller) device in the PC. Outline
also the main ICs that are used in a PC.
5.3.8
Describe, in detail, the architecture of the HX PCI chip set, and how the Pentium
processor communicates with: DRAM memory, Level-2 SRAM cache, the PCI
bus, the ISA bus and the IDE bus.
5.3.9
Explain, with reference to the PIIX3 and Pentium processor, how interrupts on the
PCI and ISA busses are dealt with.
5.3.10
Explain, with reference to the level-1 cache, the level-2 cache and DRAM, how
the processor accesses memory. What advantage does level-1 have over level-2
cache, and what advantage do these have over DRAM.
5.3.11
Discuss the power management modes supported by the PXII3, and also by the
PXII4.
5.3.12
Which interrupts are supported with the AIP and where are they typically used?
5.3.13
Explain how the ISA and IDE busses share the same control and data lines.
5.3.14
Contrast the HX motherboard with the LX motherboard.
5.4 Notes from the author
I hope that this chapter was not too heavy. It is important to realise that it is not just the
speed of the processor that defines the performance of a system - it is the cache controllers,
the bridge devices, the PCI bus, and so on. So have tried to give you an understanding of the
segmentation that is used in typical PCs. The devices used will change, but the basic concept
is likely to stay the same (I hope!). The days of a PC on a chip will happen, someday.
The most amazing thing about modern PC systems is that they are almost completely
compatible with the original PC, the big change has happened in the integration of many of
the components parts. The great strength of the PC is its availability, durability and up-
gradeability of its components. I find it amazing that it can disconnect the cable to the disk
drives, turn it round, and connect it and the system will not be damage, in any way (although
it won't start). I can even put the processor in the wrong way, and it will not damage it.
The other amazing thing about PCs is the way that new peripherals are quickly adopted,
and become standard parts of the PC. This has included CD-ROM drives, USB connectors,
PS/2-type mouse connectors, PCMCIA connectors (in notebooks), VGA graphics adaptors,
TV output, DVD drives, network cards, sound cards, and so on. Who would have believed
that such a basic system as the original PC would support all this expansion, without ever
the need to redesign it (although the PCI bus provided a new architectural design).
