SDAA081 September   2025 DP83825I

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Troubleshooting the Application
    1. 2.1 Schematic 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
      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 (MDC, MDIO)
        1. 2.2.6.1 Read and Check Register Values
    3. 2.3 MDI Health Checks
      1. 2.3.1 Magnetics
      2. 2.3.2 Probe the MDI Signals
      3. 2.3.3 Check the Link Quality
      4. 2.3.4 Compliance
    4. 2.4 RMII Health 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
  6. 3Summary
  7. 4References

2 Troubleshooting the Application

The following sections approach the debug from a high level, basic check approach which isolates subsystems of the PHY design to check if they contribute to an application issue. This document is intended to address common Ethernet issues such as:

  • Inability to ping
  • Cannot get link OR intermittent linkup
  • Linkup but seeing packet errors
  • Cannot access registers

The recommendation is to go through the following sections in order unless otherwise specified.