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

Abstract

Texas Instruments' 100Base-T1 (DP83TC811, DP83TC812) and 1000Base-T1 (DP83TG720) Automotive Ethernet physical layers (PHYs) are designed such that same PCB board can be used for either transceiver. While the hardware changes needed to make the swap are listed in the DP83TC811, DP83TG720 Rollover Document application note, there are also necessarily changes to be accounted for in software. This application note acts as a reference guide to point out the appropriate timing flowchart for these devices and distinguish between the necessary timing specifications of each device.