Intel 82555 - page 19

Datasheet 15

Networking Silicon — 82555

maintained (either positive, negative or zero). When an NRZ “1” arri v es at the inp ut of the enco der ,

the output steps to the next level. The order of steps is negative-zero-posit ive-zero which continues

periodically. The figure below illustrates this process.

4.2.3 100BASE-TX Transmit Framing

The 82555 does not differentiate between the fields of the MAC frame containing preamble, start

of frame delimiter, data and Cyclic Redundancy Check (CRC). When TXEN is asserted, the 82555

accepts data on the MII TXD[3:0] lines, encodes it, and sends it out onto the wire. The 82555

encodes the first byte of the preamble as the “JK” symbol, encodes all other pieces of data

according to the 4B/5B lookup table, and adds the “TR” code after the end of the packet (de-

assertion of TXEN). The 82555 scrambles and serializes the data into a 125 Mbps stream, encodes

it as MLT-3, and dri v es it onto the wire. If TXERR is asse rted during tr ansmissi on of val id data, the

82555 transmits an invalid “H” symbol.

Figure 6. NRZ to MLT-3 Encoding Diagram

Clock

NRZ

NRZ1

MLT-3

1100 0110

1100 0110

1100 0110

Contents

Main 82555 10/100 Mbps LAN Physical Layer Interface Networking Silicon Datasheet Product Features Page Page Contents 1.0 Introduction 1.1 Functional Overview 1.2 Compliance to Industry Standards Page 2.0 Architectural Overview 2.1 100 Mbps Mode 2.2 10 Mbps Mode Magnetics Module Datasheet 5 g Figure 4. Intel 82557/82555 Solution 2.3 Media Independent Interface (MII) 82555 82557 PCI Bus Si nals Page Page 8 Datasheet 3.1 Pin Types 3.2 Clock Pins 3.4 Media Independent Interface (MII) Pins 3.3 Twisted Pair Ethernet (TPE) Pins 3.5 Media Access Control/Repeater Interface Control Pins Datasheet 9 10 Datasheet 3.6 LED Pins 3.7 External Bias Pins Datasheet 11 3.8 Miscellaneous Control Pins 3.9 Power and Ground Pins 4.0 100BASE-TX Adapter Mode Operation 4.1 100BASE-TX Transmit Clock Generation 4.2 100BASE-TX Transmit Blocks 4.2.1 100BASE-TX 4B/5B Encoder 4.2.2 100BASE-TX Scrambler and MLT-3 Encoder Page 4.2.4 Transmit Driver 4.3 100BASE-TX Receive Blocks 4.4 100BASE-TX Collision Detection 4.5 100BASE-TX Link Integrity and Auto-Negotiation Solution 4.5.1 Link Integrity 4.5.2 Auto-Negotiation 4.5.3 Combination Tx/T4 Auto-Negotiation Solution 4.6 Auto 10/100 Mbps Speed Selection 4.7 Adapter Mode Addresses Page 5.0 10BASE-T Functionality in Adapter Mode 5.1 10BASE-T Transmit Clock Generation 5.2 10BASE-T Transmit Blocks 5.2.1 10BASE-T Manchester Encoder 5.2.2 10BASE-T Driver and Filter 5.4 10BASE-T Collision Detection 5.5 10BASE-T Link Integrity 5.6 10BASE-T Jabber Control Function Page Page 6.0 Repeater Mode 6.1 Special Repeater Features 6.2 Connectivity Page 7.0 Management Data Interface 7.1 MDI Frame Structure 7.2 MDI Registers 7.2.1 MDI Registers 0 - 7 7.2.1.1 Register 0: Control Register Bit Definitions 7.2.1.2 Register 1: Status Register Bit Definitions Datasheet 29 30 Datasheet Datasheet 31 7.2.1.6 Register 5: Auto-Negotiation Link Partner Ability Register Bit Definitions Register numbers 16, 17, 20, 21, 22, 23, 24, 25, and 27 are described in the following subsections. 7.2.1.7 Register 6: Auto-Negotiation Expansion Register Bit Definitions 7.2.2 MDI Registers 8 - 15 Registers eight through fifteen are reserved for IEEE. 7.2.3 MDI Registers 16 - 31 32 Datasheet 7.2.3.1 Register 16: 82555 Status and Control Register Bit Definitions 7.2.3.2 Register 17: 82555 Special Control Bit Definitions Datasheet 33 7.2.3.3 Register 20: 100BASE-TX Receive Disconnect Counter Bit Definitions 7.2.3.4 Register 21: 100BASE-TX Receive Error Frame Counter Bit Definitions 34 Datasheet 7.2.3.5 Register 22: Receive Symbol Error Counter Bit Definitions 7.2.3.6 Register 23: 100BASE-TX Receive Premature End of Frame Error Counter Bit Definitions 7.2.3.9 Register 27: 82555 Special Control Bit Definitions 7.2.3.7 Register 24: 10BASE-T Receive End of Frame Error Counter Bit Definitions 7.2.3.8 Register 25: 10BASE-T Transmit Jabber Detect Counter Bit Definitions 8.0 Auto-Negotiation Functionality 8.1 Description 8.2 Parallel Detect and Auto-Negotiation Page Page 9.0 LED Descriptions Page 10.0 Reset and Miscellaneous Test Modes 10.1 Reset 10.2 Loopback 10.3 Scrambler Bypass 10.4 Test Port Page Datasheet 43 11.0 Electrical Specifications and Timing Parameters 11.1 Absolute Maximum Ratings 11.3.2 10BASE-T Voltage/Current DC Characteristics 11.2 General Operating Conditions 11.3 DC Characteristics 11.3.1 MII DC Characteristics Icct10 105mA 110mA 115mA Figure 11. RBIAS10 Resistance versus I 44 Datasheet 768 Icct100 38mA 40mA 42mA 604 634 Figure 12. RBIAS100 Resistance versus I 11.4.2 MII Timing Parameters T1,T2,T3 Figure 15. MII Transmit Timing Parameters Figure 14. MII Clocks AC Timing 46 Datasheet 11.4.3 Repeater Mode Timing Parameters Datasheet 47 Figure 16. MII Receive Timing Parameters Figure 18. PORT Enable Timing Figure 17. MII Timing Parameters: MDC/MDIO 11.4.4 Transmit Packet Timing Parameters Figure 19. Transmit Frame Timing Parameters 11.4.5 Squelch Test Timing Parameters Datasheet 49 Figure 20. Squelch Test Timing Parameters 11.4.6 Jabber Timing Parameters 11.4.7 Receive Packet Timing Parameters 50 Datasheet Figure 22. Receive Packet Timing Parameters 11.4.8 10BASE-T Normal Link Pulse (NLP) Timing Parameters 11.4.9 Auto-Negotiation Fast Link Pulse (FLP) Timing Parameters Figure 23. Normal Link Pulse Timing Parameters Datasheet 51 Networking Silicon 82555 11.4.10 Reset Timing Parameters 11.4.11 X1 Clock Specifications 11.4.12 100BASE-TX Transmitter AC Specification 12.0 82555 Package Information