Auto 10/100 Mbps Speed Selection | Intel 82555 specs

Networking Silicon — 82555

The figure below illustrates an 82557/82555/PHY-T4 solution in a block diagram.

		T4
		adv
		82555	Common
			Common
			Magnetics
PCI BUS		fdx_n
PCI BUS		MII	slave tri
		MII
	82557	listat n
		listat n
		PHY-T4
			3669

Figure 8. Combination Card Example

4.6Auto 10/100 Mbps Speed Selection

The MAC may either allow the 82555 to automatically select its operating speed or force the 82555 into 10 Mbps or 100 Mbps mode. The Management Data Interface (MDI) can control the 82555 speed mode.

The 82555 autoselect function determines the operation speed of the media based on the link integrity pulses it receives. If no Fast Link Pulses (FLPs) are detected and Normal Link Pulses (NLPs) are detected, the 82555 defaults to 10 Mbps operation. If the 82555 detects a speed change, it dynamically changes its transmit clock and receive clock frequencies to the appropriate value. This change takes a maximum of five milliseconds.

4.7Adapter Mode Addresses

In DTE (adapter) mode, the 82555 supports addresses 0, 1, 2, and 3 through the pins PHYA1 and PHYA0. Four addresses are sufficient in the case of a combination adapter having three PHYs. For switch applications, the T4ADV signal should be de-asserted to allow all 32 addresses to be available in repeater mode.

Datasheet

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Intel 82555 manual Auto 10/100 Mbps Speed Selection, Adapter Mode Addresses

Contents

82555 10/100 Mbps LAN Physical Layer Interface Product Features Revision Description Networking Silicon Contents Repeater Mode Compliance to Industry Standards IntroductionFunctional Overview Networking Silicon Architectural Overview 100 Mbps Mode MII TX Interface 10 Mbps Mode Media Independent Interface MII Yes Transmit Error From RICRepeater mode only Pin Numbers and Labels Pin Definitions Pin Types Clock PinsTwisted Pair Ethernet TPE Pins Media Independent Interface MII Pins Media Access Control/Repeater Interface Control Pins External Bias Pins LED Pins Miscellaneous Control Pins VSS Power and Ground PinsVCC 100BASE-TX Transmit Blocks 100BASE-TX Adapter Mode OperationSymbol 5B Symbol Code 4B Nibble Code 100BASE-TX Transmit Clock Generation Invalid 2 100BASE-TX Scrambler and MLT-3 Encoder 3 100BASE-TX Transmit Framing NRZ to MLT-3 Encoding Diagram Vendor Model/Type 100BASE-TX Receive BlocksTransmit Driver 100BASE-TX Collision Detection Auto-Negotiation 100BASE-TX Link Integrity and Auto-Negotiation SolutionCombination Tx/T4 Auto-Negotiation Solution Link Integrity Auto 10/100 Mbps Speed Selection Adapter Mode Addresses Networking Silicon Datasheet 10BASE-T Receive Blocks 10BASE-T Functionality in Adapter Mode10BASE-T Transmit Clock Generation 10BASE-T Transmit Blocks 10BASE-T Jabber Control Function 3 10BASE-T Error Detection and Reporting10BASE-T Collision Detection 10BASE-T Link Integrity 10BASE-T Full Duplex Networking Silicon Datasheet Connectivity Repeater ModeSpecial Repeater Features Clock Signal Example MDI Frame Structure Management Data Interface Transition Bits Name Description DefaultMDI Registers MDI Registers 0 10BASE-T Register 1 Status Register Bit Definitions Register 2 82555 Identifier Register Bit Definitions MDI Registers 16 MDI Registers 8 100BASE-TX Register 17 82555 Special Control Bit Definitions 150 Actled Liled Register 22 Receive Symbol Error Counter Bit Definitions Priority Technology Bit Setting TechnologyAuto-Negotiation Functionality Description Priority Parallel Detect and Auto-Negotiation Auto-Negotiation and Parallel Detect Networking Silicon Datasheet LED Descriptions Networking Silicon Datasheet Scrambler Bypass Reset and Miscellaneous Test ModesReset Loopback Number Code Test Instruction Select Input to Tout Test Instruction Coding General Operating Conditions Electrical Specifications and Timing ParametersDC Characteristics Absolute Maximum Ratings Total supply current 230 Leakage on analog pins 11.3.3 100BASE-TX Voltage/Current DC Characteristics Symbol Parameter Conditions Min Typ Max Units AC CharacteristicsMII Clock Specifications MII Clocks AC Timing MII Timing Parameters RXC tri-stated a Repeater Mode Timing Parameters Squelch Test Timing Parameters Transmit Packet Timing Parameters Receive Packet Timing Parameters Jabber Timing Parameters Auto-Negotiation Fast Link Pulse FLP Timing Parameters 11.4.8 10BASE-T Normal Link Pulse NLP Timing Parameters 11.4.11 X1 Clock Specifications Reset Timing Parameters X1 Clock Specifications 11.4.12 100BASE-TX Transmitter AC Specification 12.0 82555 Package Information Symbol Description Min Norm Max 10.0