SNLA423A March   2023  – June 2025 DP83826E , DP83826I

 

  1.   1
  2.   Trademarks
  3. 1DP83826 Application Overview
  4. 2Troubleshooting the Application
    1. 2.1 Schematic and Layout Checklist
    2. 2.2 Device Health Checks
      1. 2.2.1 Voltage Checks
      2. 2.2.2 Probe the RESET_N Signal
      3. 2.2.3 Probe RBIAS and CEXT
      4. 2.2.4 Probe the XI Clock
      5. 2.2.5 Probe the Strap Pins During Initialization
      6. 2.2.6 Probe the Serial Management Interface Signals (MDC, MDIO)
        1. 2.2.6.1 Read and Check Register Values
          1. 2.2.6.1.1 Extended Register Access
    3. 2.3 MDI Health Checks
      1. 2.3.1 Magnetics
      2. 2.3.2 Probe the MDI Signals
      3. 2.3.3 Link Quality Check
      4. 2.3.4 Compliance
    4. 2.4 MII Health Checks
      1. 2.4.1 MII Check
      2. 2.4.2 RMII Check
    5. 2.5 Loopback and PRBS
      1. 2.5.1 Loopback Modes
      2. 2.5.2 Transmitting and Receiving Packets With the MAC
      3. 2.5.3 Transmitting and Receiving Packets With BIST
  5. 3Summary
  6. 4References
  7. 5Revision History

2.2.2 Probe the RESET_N Signal

The reset functionality on DP83826 is active low. This pin has a weak internal pull-up resistor to provide a default state if left unconnected or not driven externally.

Confirm that the controller is not driving the RESET_N signal low. Otherwise, the device can be held in reset state, and would not respond to register commands nor would link up.