SNLA452 August   2025 DP83TD510E

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Troubleshooting the Application
    1. 2.1 Schematic and Layout Checklist
    2. 2.2 Component Checklist
    3. 2.3 Device Health Checks
      1. 2.3.1 Check Voltage Supply Pins
      2. 2.3.2 Probe the RST_N Pin
      3. 2.3.3 Probe the CLKOUT Pin
      4. 2.3.4 Probe the SMI Pins
    4. 2.4 Read and Check Register Values
    5. 2.5 Verifying Strap Configuration
    6. 2.6 Loopbacks
    7. 2.7 MDI Health Checks
      1. 2.7.1 Link Up Common Issues
      2. 2.7.2 Transmit Level
        1. 2.7.2.1 Change Transmit Level
      3. 2.7.3 Time-Domain Reflectometry
      4. 2.7.4 Signal Quality Check
      5. 2.7.5 MDI Test Modes
    8. 2.8 MII Health Checks
      1. 2.8.1 RGMII
      2. 2.8.2 RMII
      3. 2.8.3 MII
  6. 3Summary
  7. 4References

2.7.3 Time-Domain Reflectometry

Time-Domain reflectometry is used to determine the quality of the cables, connectors, and terminations, in addition to estimating the cable length. This determines faults such as opens, shorts, cable impedance mismatches, bad connectors, termination mismatches, cross faults, cross shorts, and any other discontinuities along the cable.

This process involves sending a test pulse of a known amplitude of 1V through each of the wires in the pair, and measuring the return time and amplitude of the signal reflections caused by any imperfections, and the end of the cable.

For more information about the cable diagnostic toolkit of the DP83TD510, please refer to the application note linked below.

Cable Diagnostic Toolkit