10-37
PHYSICAL DESIGN AND SYSTEM DEBUGGING
lumped capacitance model for circuit capacitance measurements and must be modified slightly
when doing worst-case calculations that involve transmission line effects. The amount of modi-
fications required can be calculated by performing SPICE simulation or by using other simulation
packages.
Figure 10-29. Derating Curves for the Intel486™ Processor
10.8 BUILDING AND DEBUGGING THE Intel486™ PROCESSOR-BASED
SYSTEM
Although an Intel486 processor-based system designer should plan the entire system, it is neces-
sary to begin building different elements of the core and begin testing them before building the
final system. If a printed circuit board layout has to be done, the whole system may be simulated
before generating the net list for the layout vendor. It is advisable to work with a preliminary lay-
out to avoid the problems associated with wire wrap boards that operate at high frequencies. A
typical Intel486 processor-based system is shown in Figure 10-30.
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