Apollo Pro-133A Design Checklist; General Layout Considerations Checklist; Major Components Checklist; Table 5-3. Recommended Trace Width And Spacing - VIA Technologies Apollo Pro133A Design Manual

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5.4 Apollo Pro-133A Design Checklist

This Apollo Pro-133A (VT82C694X and VT82C686A) design checklist provides six checkup lists as a brief layout reference for
implementing most layout requirements.

5.4.1 General Layout Considerations Checklist

For most signal traces on an Apollo Pro133A motherboard layout, 5-mil trace width and 10-mil spacing are advised. To reduce
trace inductance, minimum power trace width is set at 30 mils. As a quick reference, recommended trace width and spacing for
different trace types are listed in Table 5-3.
Trace Type
In high-speed bus design, general rules for minimizing crosswalk are listed below:
•
Maximize the distance between traces. Maintain a minimum 10 mils space between traces wherever possible.
•
Avoid parallelism between traces on adjacent layers.
•
Select a board stack-up that minimizes coupling between adjacent traces.
•
The recommended impedance should be in the range of 65 ohm +/- 5 ohm.

5.4.2 Major Components Checklist

Major components for the Apollo Pro-133A based system are listed below:
•
Processor selection: Single Slot-1 CPU or Single Socket-370 CPU
•
Apollo Pro-133 A chipset combination: VT82C694X and VT82C686A
•
Apollo Pro-133A dedicate system clock synthesizers: ICS9248-39, PLL52C66-23 or IC Works W144
•
Maximum DRAM DIMM slots: 4 (Maximum 8 banks up to 2GB DRAM)
•
Maximum AGP slot: 1 only
•
Maximum PCI slots: 5
Preliminary Revision 0.5, November 19, 1999

Table 5-3. Recommended Trace Width and Spacing

Trace Width (mils)
Signal
Clock
Power
Design Guide - VT82C694X Apollo Pro133 with VT82C686A
5 or wider
15 or wider
30 or wider
90
Spacing (mils)
10 or wider
15 or wider
20 or wider
Signal Connectivity and Design Checklist