BOARD LAYOUT

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Release B

This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

6.2 High speed signals

Some Interfaces of the STPC run at high speed

and have to be carefully routed or even shielded.

Here is the list of these interfaces, in decreasing

speed order:

1) Memory Interface.

2) Graphics and video interfaces

3) PCI bus

4) 14MHz oscillator stage

All the clocks haves to be routed first and shielded

for speeds of 27MHz or more. The high speed sig-

nals follow the same contrainsts, like the memory

control signals and the PCI control signals.

The next interfaces to be routed are Memory, Vid-

eo/graphics, and PCI.

All the analog noise sensitive signals have to be

routed in a separate area and hence can be rout-

ed indepedently.

Figure 6-8. Shielding signals

ground ring

ground pad

shielded signal line

ground pad

shielded signal lines