SNLS663A December   2021  – December 2025 DP83TC814R-Q1 , DP83TC814S-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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 Diagnostic Tool Kit
        1. 7.3.1.1 Signal Quality Indicator
        2. 7.3.1.2 Electrostatic Discharge Sensing
        3. 7.3.1.3 Time Domain Reflectometry
        4. 7.3.1.4 Voltage Sensing
        5. 7.3.1.5 BIST and Loopback Modes
          1. 7.3.1.5.1 Data Generator and Checker
          2. 7.3.1.5.2 xMII Loopback
          3. 7.3.1.5.3 PCS Loopback
          4. 7.3.1.5.4 Digital Loopback
          5. 7.3.1.5.5 Analog Loopback
          6. 7.3.1.5.6 Reverse Loopback
      2. 7.3.2 Compliance Test Modes
        1. 7.3.2.1 Test Mode 1
        2. 7.3.2.2 Test Mode 2
        3. 7.3.2.3 Test Mode 4
        4. 7.3.2.4 Test Mode 5
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Down
      2. 7.4.2 Reset
      3. 7.4.3 Standby
      4. 7.4.4 Normal
      5. 7.4.5 Media Dependent Interface
        1. 7.4.5.1 100BASE-T1 Leader and 100BASE-T1 Follower Configuration
        2. 7.4.5.2 Auto-Polarity Detection and Correction
        3. 7.4.5.3 Jabber Detection
        4. 7.4.5.4 Interleave Detection
      6. 7.4.6 MAC Interfaces
        1. 7.4.6.1 Media Independent Interface
        2. 7.4.6.2 Reduced Media Independent Interface
        3. 7.4.6.3 Reduced Gigabit Media Independent Interface
        4. 7.4.6.4 Serial Gigabit Media Independent Interface
      7. 7.4.7 Serial Management Interface
        1. 7.4.7.1 Direct Register Access
        2. 7.4.7.2 Extended Register Space Access
        3. 7.4.7.3 Write Operation (No Post Increment)
        4. 7.4.7.4 Read Operation (No Post Increment)
        5. 7.4.7.5 Write Operation (Post Increment)
        6. 7.4.7.6 Read Operation (Post Increment)
    5. 7.5 Programming
      1. 7.5.1 Strap Configuration
      2. 7.5.2 LED Configuration
      3. 7.5.3 PHY Address Configuration
  9. 8 Register Maps
    1. 8.1 Register Access Summary
    2. 8.2 DP83TC814 Registers
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Physical Medium Attachment
          1. 9.2.1.1.1 Common-Mode Choke Recommendations
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Signal Traces
        2. 9.4.1.2 Return Path
        3. 9.4.1.3 Metal Pour
        4. 9.4.1.4 PCB Layer Stacking
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.1.3 Time Domain Reflectometry

Time domain reflectometry helps determine the quality of the cable, connectors and terminations in addition to estimating OPEN and SHORT faults along a cable. The DP83TC814-Q1 transmits a test pulse down the attached twisted-pair cable. Transmitted pulses continue down the cable and reflect from each imperfection and fault, allowing the device to measure the time to return and strength (amplitude) of all reflections. This technique enables the DP83TC814-Q1 to identify cable OPENs and SHORTs.

TDR is activated by setting bit[15] in register 0x1E. The procedure is as follows.

  • Configure the DP83TC814-Q1 as per the initialization settings from SNLA389 Application Note
  • Verify that the Link Partner connected to the PHY is silent. Link is down during TDR execution.
  • Run the Pre-TDR configuration settings as listed in SNLA389.
  • Start TDR by setting register 0x1E[15] to '1'.
  • Wait 100ms, read register 0x1E[1:0]
    • If the register reads 0b10 then TDR has executed successfully.
  • If TDR executed successfully then read register 0x310 to get TDR results.
    • 0x310[7]: 0 = Cable fault not detected or 1 = Cable fault detected
    • 0x310[6]: 0 = Cable fault is SHORT or 1 = Cable fault is OPEN
    • If valid cable fault is detected then 0x310[5:0] stores the location value in meters.