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

2.4 Selecting 10M with Auto-Negotiation Enabled (DP83826 Basic Mode)

KSZ8081MNX and DP83826 default to 100M speed. To select 10M speed, KSZ8081 recommends a pull-down on the strap along with a series resistor on LED. For DP83826 Basic Mode, 10M speed selection is done through register configuration and the strap resistor on Pin 31 shall be removed.

  • Remove the strap resistor on Pin 31 for 10M selection
  • Program register 0x0004 with 0x0061 to select 10M speed when Auto-Negotiation is enabled
  • Program register 0x0000 with 0x3300 to restart Auto-Negotiation