SNLS505G july   2016  – august 2023 DP83822H , DP83822HF , DP83822I , DP83822IF

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics
    6. 7.6  Timing Requirements, Power-Up Timing
    7. 7.7  Timing Requirements, Power-Up With Unstable XI Clock
    8. 7.8  Timing Requirements, Reset Timing
    9. 7.9  Timing Requirements, Serial Management Timing
    10. 7.10 Timing Requirements, 100 Mbps MII Transmit Timing
    11. 7.11 Timing Requirements, 100 Mbps MII Receive Timing
    12. 7.12 Timing Requirements, 10 Mbps MII Transmit Timing
    13. 7.13 Timing Requirements, 10 Mbps MII Receive Timing
    14. 7.14 Timing Requirements, RMII Transmit Timing
    15. 7.15 Timing Requirements, RMII Receive Timing
    16. 7.16 Timing Requirements, RGMII
    17. 7.17 Normal Link Pulse Timing
    18. 7.18 Auto-Negotiation Fast Link Pulse (FLP) Timing
    19. 7.19 10BASE-Te Jabber Timing
    20. 7.20 100BASE-TX Transmit Latency Timing
    21. 7.21 100BASE-TX Receive Latency Timing
    22. 7.22 Timing Diagrams
    23. 7.23 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Energy Efficient Ethernet
        1. 8.3.1.1 EEE Overview
        2. 8.3.1.2 EEE Negotiation
      2. 8.3.2 Wake-on-LAN Packet Detection
        1. 8.3.2.1 Magic Packet Structure
        2. 8.3.2.2 Magic Packet Example
        3. 8.3.2.3 Wake-on-LAN Configuration and Status
      3. 8.3.3 Start of Frame Detect for IEEE 1588 Time Stamp
      4. 8.3.4 Clock Output
    4. 8.4 Device Functional Modes
      1. 8.4.1  MAC Interfaces
        1. 8.4.1.1 Media Independent Interface (MII)
        2. 8.4.1.2 Reduced Media Independent Interface (RMII)
        3. 8.4.1.3 Reduced Gigabit Media Independent Interface (RGMII)
      2. 8.4.2  Serial Management Interface
        1. 8.4.2.1 Extended Register Space Access
        2. 8.4.2.2 Write Address Operation
        3. 8.4.2.3 Read Address Operation
        4. 8.4.2.4 Write (No Post Increment) Operation
        5. 8.4.2.5 Read (No Post Increment) Operation
        6. 8.4.2.6 Write (Post Increment) Operation
        7. 8.4.2.7 Read (Post Increment) Operation
        8. 8.4.2.8 Example Write Operation (No Post Increment)
        9. 8.4.2.9 Example Read Operation (No Post Increment)
      3. 8.4.3  100BASE-TX
        1. 8.4.3.1 100BASE-TX Transmitter
          1. 8.4.3.1.1 Code-Group Encoding and Injection
          2. 8.4.3.1.2 Scrambler
          3. 8.4.3.1.3 NRZ to NRZI Encoder
          4. 8.4.3.1.4 Binary to MLT-3 Converter
        2. 8.4.3.2 100BASE-TX Receiver
      4. 8.4.4  100BASE-FX
        1. 8.4.4.1 100BASE-FX Transmit
        2. 8.4.4.2 100BASE-FX Receive
      5. 8.4.5  10BASE-Te
        1. 8.4.5.1 Squelch
        2. 8.4.5.2 Normal Link Pulse Detection and Generation
        3. 8.4.5.3 Jabber
        4. 8.4.5.4 Active Link Polarity Detection and Correction
      6. 8.4.6  Auto-Negotiation (Speed / Duplex Selection)
      7. 8.4.7  Auto-MDIX Resolution
      8. 8.4.8  Loopback Modes
        1. 8.4.8.1 Near-End Loopback
        2. 8.4.8.2 MII Loopback
        3. 8.4.8.3 PCS Loopback
        4. 8.4.8.4 Digital Loopback
        5. 8.4.8.5 Analog Loopback
        6. 8.4.8.6 Far-End (Reverse) Loopback
      9. 8.4.9  BIST Configurations
      10. 8.4.10 Cable Diagnostics
        1. 8.4.10.1 TDR
      11. 8.4.11 Fast Link Down Functionality
    5. 8.5 Programming
      1. 8.5.1 Hardware Bootstrap Configurations
      2. 8.5.2 LED Configuration
      3. 8.5.3 PHY Address Configuration
    6. 8.6 Register Maps
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 TPI Network Circuit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Fiber Network Circuit
        1. 9.2.2.1 Design Requirements
          1. 9.2.2.1.1 Clock Requirements
            1. 9.2.2.1.1.1 Oscillator
            2. 9.2.2.1.1.2 Crystal
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 MII Layout Guidelines
          2. 9.2.2.2.2 RMII Layout Guidelines
          3. 9.2.2.2.3 RGMII Layout Guidelines
          4. 9.2.2.2.4 MDI Layout Guidelines
        3. 9.2.2.3 Application Curves
  11. 10Power Supply Recommendations
    1. 10.1 Power Supply Characteristics
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Signal Traces
      2. 11.1.2 Return Path
      3. 11.1.3 Transformer Layout
        1. 11.1.3.1 Transformer Recommendations
      4. 11.1.4 Metal Pour
      5. 11.1.5 PCB Layer Stacking
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Package Option Addendum
      1. 13.1.1 Packaging Information
      2. 13.1.2 Tape and Reel Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.4.10.1 TDR

The DP83822 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 DP83822 transmits a test pulse of known amplitude (1 V) down each of the two pairs of an attached cable. The transmitted signal continues down the cable and reflects from each cable imperfection, fault, connector and from the end of the cable itself. After the pulse transmission, the DP83822 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) and improperly terminated cables with ±1m accuracy.

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 following scenarios:

  • While the 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 could be automatically activated when the link fails or is dropped

TDR Auto-Run can be enabled by using bit[8] in the Control Regsiter #1 (CR1, address 0x0009). When a link drops, TDR will automatically execute and store the results in the respective TDR Cable Diagnostic Location Result Registers #1 - #5 (CDLRR, addresses 0x0180 to 0x0184) and the Cable Diagnostic Amplitude Result Registers #1 - #5 (CDLAR, addresses 0x0185 to 0x0189). TDR can also be run manually using bit[15] in the Cable Diagnostic Control Register (CDCR, address 0x001E). Cable diagnostic status is obtained by reading bits[1:0] in the CDCR. Additional TDR functions including cycle averaging, bypass channel and crossover disable can be found in the Cable Diagnostic Specific Control Register (CDSCR, address 0x0170).