Datasheet

3

Document #: 249115

Revision #: 003

Rev. Date: 08/07/01

Contents

Contents

1.0

Block Diagram ............................................................................................................................... 7

2.0

Pin Assignments and Signal Descriptions ................................................................................. 8

3.0

Functional Description................................................................................................................ 16

3.1

Introduction ......................................................................................................................... 16

3.2

Port Configuration ............................................................................................................... 17

3.2.1

Auto-Negotiation .................................................................................................... 17

3.2.2

Link Establishment and Port Connection ............................................................... 18

3.3

Interface Descriptions ......................................................................................................... 18

3.3.1

Twisted-Pair Interface ............................................................................................ 18

3.3.2

Media Independent Interface ................................................................................. 18

3.4

Repeater Operation ............................................................................................................ 19

3.4.1

100 Mbps Repeater Operation .............................................................................. 19

3.4.2

10 Mbps Repeater Operation ................................................................................ 20

3.5

Requirements ..................................................................................................................... 20

3.5.1

Power..................................................................................................................... 20

3.5.2

Clock ......................................................................................................................21

3.5.3

Bias Resistor.......................................................................................................... 21

3.5.4

Reset ..................................................................................................................... 21

3.5.5

IRB Bus Pull-ups.................................................................................................... 21

3.6

LED Operation .................................................................................................................... 21

3.6.1

LEDs at Start-up .................................................................................................... 21

3.6.2

LED Event Stretching ............................................................................................ 22

3.6.3

Serial LED Interface............................................................................................... 22

3.6.4

Serial Shifting......................................................................................................... 22

3.6.4.1

Serial LED Signals ................................................................................. 23

3.6.4.2

Activity Graph LEDs............................................................................... 23

3.6.5

Direct Drive LEDs .................................................................................................. 24

3.6.6

LED Modes ............................................................................................................ 24

3.6.6.1

LED Mode 1 ........................................................................................... 25

3.6.6.2

LED Mode 2 ........................................................................................... 25

3.6.6.3

LED Mode 3 ........................................................................................... 26

3.6.6.4

LED Mode 4 ........................................................................................... 28

3.7

IRB Operation ..................................................................................................................... 28

3.7.1

IRB Signal Types ................................................................................................... 28

3.7.2

10M-Only Operation .............................................................................................. 29

3.7.2.1

MAC IRB Access ................................................................................... 29

3.7.3

LXT98x/91x/98xx Compatibility ............................................................................. 29

3.8

MII Port Operation .............................................................................................................. 31

3.8.1

Preamble Handling ................................................................................................ 31

4.0

Application Information .............................................................................................................. 32

4.1

General Design Guidelines ................................................................................................. 32

4.2

Power and Ground.............................................................................................................. 33

4.2.1

Supply Filtering ...................................................................................................... 33

4.2.2

Ground Noise......................................................................................................... 33