Page 274 - Embedded Microprocessor Systems Real World Design

Industry-Standard 10
Embedded Platforms

As mentioned earlier, one characteristic of an embedded system is that it is self-
contained, requiring no user input to get started. There are some exceptions to
that rule, which we’ll look at in this chapter. A problem with developing all parts
of an embedded system is that all the interfaces-Ethernet, FDDI, and W232-
must be developed along with the system. You must design an interface circuit (or
board) and cannot take advantage of off-the-shelf boards and driver software. One
platform, however, allows you to use existing parts-the personal computer (PC)
platform, in this case the IBM PC/AT and its derivatives.
If you design an embedded system around a PC, you can get interface boards,
disk drive interfaces, A/D and D/A interfaces, and a number of other components
from existing vendors and often with driver software.

Advantages of Using a PC Platform

There are a number of reasons why some developers choose the PC platform for
development.

Speed of Development
An embedded system designed from scratch requires that boards be designed,
fabricated, and debugged. The software must be tested and debugged on the target
system. If a PC platform is used, the boards are available and the software can be
written and debugged in the same environment. In addition, PC hardware with
high-speed buses like Peripheral Component Interconnect (PCI) takes more design
effort to get right. If you buy the boards, someone else has done the job of making
them work.

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