SNLA404 December   2022 DP83TC811R-Q1 , DP83TC811S-Q1 , DP83TC812R-Q1 , DP83TC812S-Q1 , DP83TG720R-Q1 , DP83TG720S-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2PHY Link-up Sequence
    1. 2.1 Microcontroller Initialization
    2. 2.2 Power-up Sequence
      1. 2.2.1 All Supplies Ramped
      2. 2.2.2 PHY Clock Required Good
      3. 2.2.3 SMI Access Available
      4. 2.2.4 PHY Bootstraps Sampled
    3. 2.3 Check Device ID
    4. 2.4 PHY Initialization
      1. 2.4.1 Managed or Autonomous Mode?
      2. 2.4.2 Program PHY Configuration Settings, Enable Link Start-up
      3. 2.4.3 Program PHY Into Autonomous Mode
      4. 2.4.4 Soft Restart or Polling for Link
      5. 2.4.5 Results of Link Polling
    5. 2.5 Post Start-up Operation
    6. 2.6 Reset Sequence
      1. 2.6.1 Reset Initiated
      2. 2.6.2 SMI Access Available
      3. 2.6.3 Transition to Normal Operation
  5. 3Summary
  6.   A Appendix

2.4.1 Managed or Autonomous Mode?

Depending on the strapping settings, the PHY is either in autonomous or managed mode upon power up. Compared to managed mode, if a PHY is in autonomous mode, it is possible that the PHY links up with the link partner. To configure the PHY appropriately, the linkup must be disabled.