Intel 82555 manual MDI Registers 0, Transition, Bits Name Description Default

Page 32

82555 — Networking Silicon

The 82555 address can be configured to four 0 through 3 in DTE (adapter) mode and 0 through 31 in repeater mode. A special functions for switches allows 32 addresses to exist in repeater mode. The management frame structure is as follows:

Transition

ST

OP

PHYAD

REGAD

TA

DATA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

READ

<01>

<10>

<AAAAA>

<RRRRR>

<X0>

16 bits

 

 

 

 

 

 

 

WRITE

<01>

<01>

<AAAAA>

<RRRRR>

<10>

16 bits

 

 

 

 

 

 

 

7.2MDI Registers

MDI registers are described in the following subsections and the acronyms mentioned in the registers are defined as follows:

SC - Self Cleared.

RO -Read Only.

P- External pin affects 82555 register content.

LL- Latch Low. LH - Latch High.

7.2.1MDI Registers 0 - 7

7.2.1.1Register 0: Control Register Bit Definitions

Bit(s)

Name

 

Description

Default

R/W

 

 

 

 

 

 

 

 

 

 

15

Reset

This bit sets the status and control register of the 82555

0

RW

 

 

to their default states and is self-clearing. The PHY

 

SC

 

 

returns a value of 1b until the reset process has

 

 

 

 

 

 

 

completed and accepts a read or write transaction.

 

 

 

 

1

= PHY Reset

 

 

 

 

0

= Normal operation

 

 

 

 

 

 

 

14

Loopback

This bit enables loopback of transmit data nibbles from

0

RW

 

 

the TXD[3:0] signals to the receive data path. The

 

P

 

 

82555’s receive circuitry is isolated from the network.

 

 

 

 

 

 

 

Note that this may cause the descrambler to lose

 

 

 

 

synchronization and produce 560 nanoseconds of “dead

 

 

 

 

time.”

 

 

 

 

Note also that the loopback configuration bit takes priority

 

 

 

 

over the Loopback MDI bit.

 

 

 

 

1

= Loopback enabled

 

 

 

 

0

= Loopback disabled (normal operation)

 

 

 

 

 

 

 

13

Speed Selection

This bit controls speed when Auto-Negotiation is disabled

1

RW

 

 

and is valid on read when Auto-Negotiation is disabled.

 

P

 

 

 

 

 

 

 

1

= 100 Mbps

 

 

 

 

0

= 10 Mbps

 

 

 

 

 

 

 

12

Auto-Negotiation

This bit enables Auto-Negotiation. Bits 13 and 8, Speed

1

RW

 

Enable

Selection and Duplex Mode, respectively, are ignored

 

 

 

 

when Auto-Negotiation is enabled.

 

 

 

 

1

= Auto-Negotiation enabled

 

 

 

 

0

= Auto-Negotiation disabled

 

 

 

 

 

 

 

 

28

Datasheet

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Contents Product Features 82555 10/100 Mbps LAN Physical Layer InterfaceNetworking Silicon Revision DescriptionContents Repeater Mode Compliance to Industry Standards IntroductionFunctional Overview Networking Silicon 100 Mbps Mode Architectural Overview10 Mbps Mode MII TX InterfaceMedia Independent Interface MII Yes Transmit Error From RICRepeater mode only Pin Definitions Pin Numbers and LabelsClock Pins Twisted Pair Ethernet TPE PinsMedia Independent Interface MII Pins Pin TypesMedia Access Control/Repeater Interface Control Pins LED Pins External Bias PinsMiscellaneous Control Pins VSS Power and Ground PinsVCC 100BASE-TX Adapter Mode Operation Symbol 5B Symbol Code 4B Nibble Code100BASE-TX Transmit Clock Generation 100BASE-TX Transmit Blocks2 100BASE-TX Scrambler and MLT-3 Encoder InvalidNRZ to MLT-3 Encoding Diagram 3 100BASE-TX Transmit FramingVendor Model/Type 100BASE-TX Receive BlocksTransmit Driver 100BASE-TX Collision Detection 100BASE-TX Link Integrity and Auto-Negotiation Solution Combination Tx/T4 Auto-Negotiation SolutionLink Integrity Auto-NegotiationAdapter Mode Addresses Auto 10/100 Mbps Speed SelectionNetworking Silicon Datasheet 10BASE-T Functionality in Adapter Mode 10BASE-T Transmit Clock Generation10BASE-T Transmit Blocks 10BASE-T Receive Blocks3 10BASE-T Error Detection and Reporting 10BASE-T Collision Detection10BASE-T Link Integrity 10BASE-T Jabber Control Function10BASE-T Full Duplex Networking Silicon Datasheet Connectivity Repeater Mode Special Repeater Features Clock Signal Example Management Data Interface MDI Frame StructureBits Name Description Default MDI RegistersMDI Registers 0 TransitionRegister 1 Status Register Bit Definitions 10BASE-TRegister 2 82555 Identifier Register Bit Definitions MDI Registers 8 MDI Registers 16Register 17 82555 Special Control Bit Definitions 100BASE-TX150 Register 22 Receive Symbol Error Counter Bit Definitions Actled LiledBit Setting Technology Auto-Negotiation FunctionalityDescription Priority TechnologyParallel Detect and Auto-Negotiation PriorityAuto-Negotiation and Parallel Detect Networking Silicon Datasheet LED Descriptions Networking Silicon Datasheet Reset and Miscellaneous Test Modes ResetLoopback Scrambler BypassTest Instruction Coding Number Code Test Instruction Select Input to ToutElectrical Specifications and Timing Parameters DC CharacteristicsAbsolute Maximum Ratings General Operating Conditions11.3.3 100BASE-TX Voltage/Current DC Characteristics Total supply current 230 Leakage on analog pinsSymbol Parameter Conditions Min Typ Max Units AC CharacteristicsMII Clock Specifications MII Timing Parameters MII Clocks AC TimingRepeater Mode Timing Parameters RXC tri-stated aTransmit Packet Timing Parameters Squelch Test Timing ParametersJabber Timing Parameters Receive Packet Timing Parameters11.4.8 10BASE-T Normal Link Pulse NLP Timing Parameters Auto-Negotiation Fast Link Pulse FLP Timing ParametersReset Timing Parameters 11.4.11 X1 Clock Specifications11.4.12 100BASE-TX Transmitter AC Specification X1 Clock SpecificationsSymbol Description Min Norm Max 12.0 82555 Package Information10.0
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