SNLA423 March   2023 DP83826E

 

  1. 1Trademarks
  2. 2DP83826 Application Overview
  3. 3Troubleshooting the Application
    1. 3.1 Read and Check Register Values
    2. 3.2 Schematic and Layout Checklist
    3. 3.3 Component Checklist
    4. 3.4 Peripheral Pin Checks
      1. 3.4.1 Power Supplies
      2. 3.4.2 Probe the XI Clock
      3. 3.4.3 Probe the RESET_N Signal
      4. 3.4.4 Probe the Strap Pins During Initialization
      5. 3.4.5 Probe the Serial Management Interface Signals (MDC, MDIO)
      6. 3.4.6 Probe the MDI Signals
    5. 3.5 Link Quality Check
    6. 3.6 Built-In Self Test with Various Loopback Modes
    7. 3.7 Debugging MAC Interface
    8. 3.8 Tools and References
      1. 3.8.1 DP83826 Register Access
      2. 3.8.2 Extended Register Access
      3. 3.8.3 Application Note References
  4. 4Conclusion
  5. 5Revision History

3.4.2 Probe the XI Clock

Verify the frequency and signal integrity. For link integrity the clock must be 25 MHz ±50 ppm in MII and RMII Master modes, 50-MHz ±50 ppm in RMII Slave mode.

If using a crystal as the clock source, probe the CLK_OUT signal. Probing the crystal can change the capacitive loading and therefore change the operational frequency. The default signal on CLK_OUT is a buffered version of the XI reference and will provide a representative measurement.