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5 decoupling guidelines: intel, 440gx agpset platform – Intel 440GX User Manual

Page 55

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Intel

®

440GX AGPset Design Guide

2-31

Motherboard Layout and Routing Guidelines

Because of the specifics of an ATX layout, it is recommended that the PIIX4E component is at the
“END” of the PCI bus, as shown in

Figure 2-28

. This insures proper “termination” of the PCI Bus

signals.

2.9.5

Decoupling Guidelines: Intel

®

440GX AGPset Platform

Decoupling caps should be placed at the corners of the 443GX(BGA Package). A minimum of four
0.1uF and four 0.01 uF are recommended. The system bus, AGP, PCI, and DRAM interface can
“break-out” from the BGA package on all four sides. Additional caps will also help reduce EMI
and cross-talk.

Note:

There are other discrete components for V

TT

, GTL Ref Voltages that must be also considered when

routing around the 82443GX.

Figure 2-28. PCI Bus Layout Example

82443GX

PIIX4E

Figure 2-29. 82443GX Decoupling

82443GX

Host Bridge

Controller

492 BGA

0.1uF

0.01uF

0.1uF
0.01uF

0.1uF

0.01uF

0.1uF
0.01uF

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