Product specifications
Design Guide - VT82C694X Apollo Pro133 with VT82C686A
Preliminary Revision 0.5, November 19, 1999 i Table of Contents
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TABLE OF CONTENTS
Revision History............................................................................................................................................i
Table of Contents ..........................................................................................................................................i
List of Figures...............................................................................................................................................i
List of Tables.................................................................................................................................................i
Introduction .................................................................................................................................................1
1.1 About This Design Guide ................................................................................................................................1
1.2 Apollo Pro133A Chipset Overview .................................................................................................................2
1.2.1 VT82C694X Apollo Pro133A North Bridge Features ..................................................................................................2
1.2.2 Super South (VT82C686A) Chipset Features...............................................................................................................3
1.2.3 System Block Diagram................................................................................................................................................4
1.3 System Design Recommendations...................................................................................................................5
Motherboard Design Guidelines ..................................................................................................................7
2.1 Ballout Assignment..........................................................................................................................................7
2.1.1 Apollo Pro133A North Bridge Ballout Assignment......................................................................................................7
2.1.2 "Super South" South Bridge Ballout Assignment......................................................................................................... 8
2.2 Motherboard Description................................................................................................................................9
2.2.1 Slot-1 Motherboard Placement and Routing................................................................................................................. 9
2.2.1.1 ATX Form Factor for Slot-1 System................................................................................................................... 10
2.2.1.2 Micro ATX Form Factor for Slot-1 System......................................................................................................... 11
2.2.2 Socket-370 Motherboard Placement and Routing....................................................................................................... 12
2.2.2.1 ATX Form Factor for Socket-370 System ........................................................................................................... 13
2.2.2.2 Micro ATX Form Factor for Socket-370 System................................................................................................. 14
2.2.3 Printed Circuit Board Description.............................................................................................................................. 15
2.2.3.1 Four-Layer Board...............................................................................................................................................15
2.2.3.2 Six-Layer Board................................................................................................................................................. 16
2.2.4 On Board Power Regulation...................................................................................................................................... 17
2.2.5 Capacitive Decoupling.............................................................................................................................................. 17
2.2.5.1 Single Slot-1 Processor Capacitive Decoupling................................................................................................... 18
2.2.5.2 Single Socket-370 Processor Capacitive Decoupling........................................................................................... 19
2.2.5.3 Apollo Pro133A Chipset Capacitive Decoupling.................................................................................................20
2.2.5.4 DRAM Module Capacitive Decoupling .............................................................................................................. 20
2.2.6 Power Plane Partitions ..............................................................................................................................................21
2.2.6.1 Power Plane Partitions for Slot-1 Motherboard ...................................................................................................21
2.2.6.2 Power Plane Partitions for Socket-370 Motherboard ...........................................................................................23
2.2.7 Chipset Power and Ground Layout Recommendations............................................................................................... 25
2.2.8 Power Up Configuration ...........................................................................................................................................27
2.2.8.1 VT82C694X Power Up Strappings..................................................................................................................... 28
2.2.8.2 VT82C686A Power Up Strappings..................................................................................................................... 28
2.3 General Layout and Routing Guidelines ......................................................................................................29
2.3.1 Trace Attribute Recommendations............................................................................................................................. 29
2.3.2 Apollo Pro133A Clock Layout Recommendations..................................................................................................... 30
2.3.2.1 Clock Requirements ........................................................................................................................................... 30
2.3.2.2 Clocking Scheme ............................................................................................................................................... 31
2.3.2.3 Clock Routing Considerations ............................................................................................................................ 32
2.3.2.4 System Clock Combinations............................................................................................................................... 33
2.3.2.5 Host CPU Clock and SDRAM Clock Signals...................................................................................................... 34