AN84REV1

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CS8920 Technical Reference Manual

TABLE OF CONTENTS

CS8920 ETHERNET CONTROLLER TECHNICAL REFERENCE MANUAL ..............1

1.0 INTRODUCTION TO CS8920 TECHNICAL REFERENCE MANUAL ....................6

2.0 HARDWARE DESIGN .....................................................................................................9

2.1.1 General Description ......................................................................................................9

2.1.2 Board Design Considerations .......................................................................................9

2.1.2.1 Crystal Oscillator................................................................................................................................................ 9

2.1.2.2 ISA Bus Interface ............................................................................................................................................... 9

2.1.2.4 EEPROM ..........................................................................................................................................................10

2.1.2.5 LEDs .................................................................................................................................................................10

2.1.2.7 10BASE-2 and AUI Interfaces...........................................................................................................................10

2.1.3 Logic Schematics ........................................................................................................10

2.1.4 Component Placement and Signal Routing.................................................................10

2.2.1 General guidelines ......................................................................................................20

2.2.2 Power supply connections...........................................................................................20

2.2.2.1 Two layered printed circuit board (PCB)............................................................................................................22

2.2.2.2 Multi-layered printed circuit board.....................................................................................................................22

2.2.3 Routing of the digital signals ......................................................................................32

2.2.4 Routing of the analog signals......................................................................................32

2.2.4.1 Routing of the clock signals:...............................................................................................................................32

2.2.4.2 Biasing resistor at RES pin of the CS8920 ..........................................................................................................32

2.2.4.3 Routing of the 10BASE-T signals.......................................................................................................................32

2.2.4.4 Routing of the AUI signals..................................................................................................................................32

3.0 EEPROM-BASED CONFIGURATION.........................................................................36

3.2.1 Reset Configuration Block Format ..............................................................................36