SNLS614C September   2018  – April 2024 DP83869HM

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  WoL (Wake-on-LAN) Packet Detection
        1. 7.3.1.1 Magic Packet Structure
        2. 7.3.1.2 Wake-on-LAN Configuration and Status
      2. 7.3.2  Start of Frame Detect for IEEE 1588 Time Stamp
        1. 7.3.2.1 SFD Latency Variation and Determinism
          1. 7.3.2.1.1 1000Mb SFD Variation in Master Mode
          2. 7.3.2.1.2 1000Mb SFD Variation in Slave Mode
          3. 7.3.2.1.3 100-Mb SFD Variation
      3. 7.3.3  Clock Output
      4. 7.3.4  Loopback Mode
        1. 7.3.4.1 Near-End Loopback
          1. 7.3.4.1.1 MII Loopback
          2. 7.3.4.1.2 PCS Loopback
          3. 7.3.4.1.3 Digital Loopback
          4. 7.3.4.1.4 Analog Loopback
          5. 7.3.4.1.5 External Loopback
          6. 7.3.4.1.6 Far-End (Reverse) Loopback
        2.       37
      5. 7.3.5  BIST Configuration
      6. 7.3.6  Interrupt
      7. 7.3.7  Power-Saving Modes
        1. 7.3.7.1 IEEE Power Down
        2. 7.3.7.2 Active Sleep
        3. 7.3.7.3 Passive Sleep
      8. 7.3.8  Mirror Mode
      9. 7.3.9  Speed Optimization
      10. 7.3.10 Cable Diagnostics
        1. 7.3.10.1 TDR
      11. 7.3.11 Fast Link Drop
      12. 7.3.12 Jumbo Frames
    4. 7.4 Device Functional Modes
      1. 7.4.1  Copper Ethernet
        1. 7.4.1.1 1000BASE-T
        2. 7.4.1.2 100BASE-TX
        3. 7.4.1.3 10BASE-Te
      2. 7.4.2  Fiber Ethernet
        1. 7.4.2.1 1000BASE-X
        2. 7.4.2.2 100BASE-FX
      3. 7.4.3  Serial GMII (SGMII)
      4. 7.4.4  Reduced GMII (RGMII)
        1. 7.4.4.1 1000Mbps Mode Operation
        2. 7.4.4.2 1000Mbps Mode Timing
        3. 7.4.4.3 10 and 100Mbps Mode
      5. 7.4.5  Media Independent Interface (MII)
      6. 7.4.6  Bridge Modes
        1. 7.4.6.1 RGMII-to-SGMII Mode
        2. 7.4.6.2 SGMII-to-RGMII Mode
        3.       67
      7. 7.4.7  Media Convertor Mode
      8. 7.4.8  Register Configuration for Operational Modes
        1. 7.4.8.1 RGMII-to-Copper Ethernet Mode
        2. 7.4.8.2 RGMII-to-1000Base-X Mode
        3. 7.4.8.3 RGMII-to-100Base-FX Mode
        4. 7.4.8.4 RGMII-to-SGMII Bridge Mode
        5. 7.4.8.5 1000M Media Convertor Mode
        6. 7.4.8.6 100M Media Convertor Mode
        7. 7.4.8.7 SGMII-to-Copper Ethernet Mode
      9. 7.4.9  Serial Management Interface
        1. 7.4.9.1 Extended Register Space Access
          1. 7.4.9.1.1 Read (No Post Increment) Operation
          2. 7.4.9.1.2 Write (No Post Increment) Operation
      10. 7.4.10 Auto-Negotiation
        1. 7.4.10.1 Speed and Duplex Selection - Priority Resolution
        2. 7.4.10.2 Master and Slave Resolution
        3. 7.4.10.3 Pause and Asymmetrical Pause Resolution
        4. 7.4.10.4 Next Page Support
        5. 7.4.10.5 Parallel Detection
        6. 7.4.10.6 Restart Auto-Negotiation
        7. 7.4.10.7 Enabling Auto-Negotiation Through Software
        8. 7.4.10.8 Auto-Negotiation Complete Time
        9. 7.4.10.9 Auto-MDIX Resolution
    5. 7.5 Programming
      1. 7.5.1 Strap Configuration
        1. 7.5.1.1 Straps for PHY Address
        2. 7.5.1.2 Strap for DP83869HM Functional Mode Selection
        3. 7.5.1.3 LED Default Configuration Based on Device Mode
        4. 7.5.1.4 Straps for RGMII/SGMII to Copper
        5. 7.5.1.5 Straps for RGMII to 1000Base-X
        6. 7.5.1.6 Straps for RGMII to 100Base-FX
        7. 7.5.1.7 Straps for Bridge Mode (SGMII-RGMII)
        8. 7.5.1.8 Straps for 100M Media Convertor
        9. 7.5.1.9 Straps for 1000M Media Convertor
      2. 7.5.2 LED Configuration
      3. 7.5.3 Reset Operation
        1. 7.5.3.1 Hardware Reset
        2. 7.5.3.2 IEEE Software Reset
        3. 7.5.3.3 Global Software Reset
        4. 7.5.3.4 Global Software Restart
    6. 7.6 Register Maps
      1. 7.6.1 DP83869 Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Copper Ethernet Typical Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Clock Input
            1. 8.2.1.2.1.1 Crystal Recommendations
            2. 8.2.1.2.1.2 External Clock Source Recommendation
          2. 8.2.1.2.2 Magnetics Requirements
            1. 8.2.1.2.2.1 Magnetics Connection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Fiber Ethernet Typical Ethernet
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Transceiver Connections
        3. 8.2.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Two-Supply Configuration
      2. 8.3.2 Three-Supply Configuration
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Signal Traces
          1. 8.4.1.1.1 MAC Interface Layout Guidelines
            1. 8.4.1.1.1.1 SGMII Layout Guidelines
            2. 8.4.1.1.1.2 RGMII Layout Guidelines
          2. 8.4.1.1.2 MDI Layout Guidelines
        2. 8.4.1.2 Return Path
        3. 8.4.1.3 Transformer Layout
        4. 8.4.1.4 Metal Pour
        5. 8.4.1.5 PCB Layer Stacking
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.3.10.1 TDR

The DP83869HM uses Time Domain Reflectometry (TDR) to determine the quality of the cables, connectors, and terminations in addition to estimating the cable length. Some of the possible problems that can be diagnosed include opens, shorts, cable impedance mismatch, bad connectors, termination mismatches, cross faults, cross shorts, and any other discontinuities along the cable.

The DP83869HM transmits a test pulse of known amplitude down each of the two pairs of an attached cable. The transmitted signal continues down the cable and reflects from each cable imperfection, fault, bad connector, and from the end of the cable itself. After the pulse transmission, the DP83869HM measures the return time and amplitude of all these reflected pulses. This technique enables measuring the distance and magnitude (impedance) of non-terminated cables (open or short), discontinuities (bad connectors), improperly-terminated cables, and crossed pairs wires with ±1m accuracy.

The DP83869HM also uses data averaging to reduce noise and improve accuracy. The DP83869HM can record up to five reflections within the tested pair. If more than 5 reflections are recorded, the DP83869HM saves the first 5 of them. If a cross fault is detected, the TDR saves the first location of the cross fault and up to 4 reflections in the tested channel. The DP83869HM TDR can measure cables beyond 100m in length.

For all TDR measurements, the transformation between time of arrival and physical distance is done by the external host using minor computations (such as multiplication, addition, and lookup tables). The host must know the expected propagation delay of the cable, which depends, among other things, on the cable category (for example, CAT5, CAT5e, or CAT6).

TDR measurement is allowed in the DP83869HM in the following scenarios:

  • While Link partner is disconnected – cable is unplugged at the other side
  • Link partner is connected but remains quiet (for example, in power-down mode)
  • TDR can be automatically activated when the link fails or is dropped by setting bit 7 of register 9h (CFG1). The results of the TDR run after the link fails are saved in the TDR registers.

Software could read these registers at any time to apply post processing on the TDR results. This mode is designed for cases when the link is dropped due to cable disconnections. After a link failure, for instance, the line is quiet to allow a proper function of the TDR.