SNLA417 January   2023 DP83TC812R-Q1 , DP83TC812S-Q1

 

  1.   Abstract
  2. 1Introduction
    1. 1.1 Acronyms
  3. 2TC10 Test Setup
    1. 2.1 Overview
    2. 2.2 Wakeup to Linking Sequence
  4. 3Measurement Summary
    1. 3.1 Complete Timing Diagram
    2. 3.2 Measurement Summary
    3. 3.3 LP1 Wake to Linking Time
  5. 4Timing Measurements
    1. 4.1 LP1 WAKE to INH (T1)
    2. 4.2 LP1 INH to WUP (T2)
    3. 4.3 WUP to PHY INH (T3)
    4. 4.4 PHY INH/Buck EN to Buck nRESET (T4)
    5. 4.5 Buck nRESET/PMIC Enable to MCU nReset (T5)
    6. 4.6 MCU nReset to MDIO Communication (T6 and T7)
    7. 4.7 MDIO Master Configuration + Linking (T8 and T9)
  6. 5Measurement Evaluation
    1. 5.1 Recommendations for Optimizing Variable TC10 Times
      1. 5.1.1 Improving MCU Boot-up Time (T6)
      2. 5.1.2 Improving MDIO State Machine (T7)
      3. 5.1.3 Optimizing MDIO Timeline (T8)
        1. 5.1.3.1 Optimizing Master Configuration by Removing Polling
        2. 5.1.3.2 Optimizing Master Configuration by Improving MDC
      4. 5.1.4 PHY Configuration During Sleep
      5. 5.1.5 Other Configurable Values
    2. 5.2 Alternative TC10 Test
  7. 6Conclusion
  8. 7References

4.6 MCU nReset to MDIO Communication (T6 and T7)

The AM273x-Q1 starts the boot-up process once the nReset goes HIGH. When booted, the MDIO eventually begins the master configuration depending on when the configuration is started in software. As Section 5.1 shows, these steps are dependent on the software. Therefore, for times T6 and T7, it is more beneficial to view recommendations for improving TC10 wake-up time.