SNLA443 December   2023 DP83869HM

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1DP83869 Application Overview
  5. 2Troubleshooting the Application
    1. 2.1 Configuring Correct Operational Mode
    2. 2.2 Schematic and Layout Checklist
    3. 2.3 Component Checklist
    4. 2.4 Peripheral Pin Checks
      1. 2.4.1 Power Supplies
      2. 2.4.2 RBIAS Voltage and Resistance
      3. 2.4.3 Probe the XI Clock
      4. 2.4.4 Probe the RESET_N Signal
      5. 2.4.5 Probe the Strap Pins During Initialization
      6. 2.4.6 Probe the Serial Management Interface Signals (MDC, MDIO)
      7. 2.4.7 Probe the MDI Signals
    5. 2.5 Built-In Self Test with Various Loopback Modes
    6. 2.6 Debugging MAC Interface
      1. 2.6.1 RGMII
      2. 2.6.2 SGMII
  6. 3Operational Mode Clarification
    1. 3.1 Bridge Modes
    2. 3.2 Fiber Configuration
      1. 3.2.1 Fiber Registers
  7. 4Tools and References
    1. 4.1 DP83869HM Register Access
    2. 4.2 Extended Register Access
      1. 4.2.1 Read (No Post Increment) Operation
      2. 4.2.2 Write (No Post Increment) Operation
    3. 4.3 Software and Driver Debug on Linux
      1. 4.3.1 Common Terminal Outputs
  8. 5Summary
  9. 6References

3.2 Fiber Configuration

DP83869HM is capable of 100Base-FX and 1000Base-X fiber communication. When using fiber, speed is not determined by auto-negotiation. Both sides of the link must be configured to the same operating speed. The pins used for fiber are also the same pins used for SGMII: SIP/SIN and SOP/SON. The DP83869HM must be set to either SGMII to Copper or RGMII/MII to fiber. A SGMII to fiber connection is not possible.

Table 3-1 Differential SGMII or Fiber Data Pins Description
Pin I/O Type Description
NO. Name
14 SON O Analog Differential SGMII or Fiber Data Output: This signal carries data from the PHY to the MAC, fiber transceiver, or link partner in SGMII and fiber modes. This pin is AC-coupled to the distant device through a 0.1-µF capacitor. This pin provides LVDS signals. Additional components can be required for the optical transceiver.
15 SOP O Analog
16 SIP I Analog Differential SGMII or Fiber Data Input: This signal carries data from the MAC, fiber transceiver, or link partner, to the PHY in SGMII and fiber modes. This pin is AC-coupled to the distant device through a 0.1-µF capacitor. This pin accepts LVDS signals. Additional components can be required for the optical transceiver.
17 SIN I Analog