SNLA338A January   2020  – August 2022 DP83826E

 

  1.   KSZ8081MNX/RNB to DP83826 System Rollover
  2.   Trademarks
  3. 1Purpose
  4. 2Required Changes
    1. 2.1 Strap Resistor Value
    2. 2.2 External Capacitor on Pin 2
    3. 2.3 Duplex Strap on Pin 16 (DP83826 Basic Mode)
    4. 2.4 Selecting 10M with Auto-Negotiation Enabled (DP83826 Basic Mode)
    5. 2.5 Configuring LED_1 for Tx and Rx Activity for EtherCAT Slave (DP83826 Basic Mode)
    6. 2.6 Thermal Pad Adjustments in Layout
    7. 2.7 Physical Layer ID Register
  5. 3Potential Changes
    1. 3.1 MDIO Pull-Up Resistor on Pin 11
    2. 3.2 MDIO Register Writes
    3. 3.3 Capacitors on Center Tap of Magnetics
  6. 4Informational Changes
  7. 5Pinout Mapping
    1. 5.1 Pin Mapping
  8. 6DP83826 Strap Configurations
    1. 6.1 Bootstrap Configurations
  9. 7Revision History

3.2 MDIO Register Writes

The DP83826 and KSZ8081MNX/RNB have both standard and extended SMI/MIIM (MDIO) registers.

DP83826 can access the standard registers through the indirect method (using standard registers 0x000D and 0x000E as outlined in IEEE 802.3). However, Microchip KSZ8081MNX/RNB can only access the standard register set through the direct method (without using 0x000D and 0x000E registers).

KSZ8081MNX/RNB also specifies the MMD address for all extended registers (for example “2 h”) while DP83826 only uses MMD address 31 (0x001F) for all extended register writes and reads.