Page 93 - A Practical Guide from Design Planning to Manufacturing

Computer Components 69

Conclusion

When looking at a computer, the most noticeable features are things like
the monitor, keyboard, mouse, and disk drives, but these are all simply
input and output devices, ways of getting information into or out of the com-
puter. For computer performance or compatibility, the components that are
most important are those that are the least visible, the microprocessor,
chipset, and motherboard. These components and how well they com-
municate with the rest of the system will determine the performance of
the product, and it is the overall performance of the product and not the
processor that matters. To create a product with the desired performance,
we must design the processor to work well with the other components.
The way a processor will communicate must be considered before
starting any design. As processor performance has increased, the com-
ponents that move data into and out of the processor have become
increasingly important. An increasing variety of available components
and bus standards have made the flexibility of separate chipsets more
attractive, but at the same time the need for lower latencies encourages
building more communication logic directly into the processor. The right
trade-off will vary greatly, especially since today processors may go into
many products very different from a traditional computer.
Handheld devices, entertainment electronics, or other products with
embedded processors may have very different performance requirements
and components than typical PCs, but they still must support buses for
communication and deal with rapidly changing standards. The basic
need to support data into and out of a processor, nonvolatile storage, and
peripherals is the same for a MP3 player or a supercomputer. Keeping
in mind these other components that will shape the final product, we are
ready to begin planning the design of the microprocessor.

Key Concepts and Terms
BIOS, POST MCH, GMCH, ICH
Bus Motherboard
Chipset Northbridge, Southbridge
DRAM, SRAM, SDRAM RAMDAC
FireWire, USB Super I/O
Hit rate Voltage regulator (VR)

Review Questions
1. How do bus frequencies limit processor frequencies?
2. How is information read from and written to a one-transistor DRAM
cell?