SDAA516 August   2026 AM620-Q1 , AM623 , AM625-Q1 , AM62A1-Q1 , AM62A3-Q1 , AM62A7-Q1 , AM62D-Q1 , AM62L , AM62P-Q1 , DRA821U-Q1 , DRA829V-Q1 , TDA4AEN-Q1 , TDA4AH-Q1 , TDA4AL-Q1 , TDA4AP-Q1 , TDA4APE-Q1 , TDA4VE-Q1 , TDA4VEN-Q1 , TDA4VH-Q1 , TDA4VL-Q1 , TDA4VP-Q1 , TDA4VPE-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Purpose
    2. 1.2 Scope
  5. 2Detailed Description
    1. 2.1 AM62Ax QSPI Boot Overview
      1. 2.1.1 Boot Preconditions
      2. 2.1.2 Boot ROM Read Sequence
    2. 2.2 Flash Addressing Architecture
      1. 2.2.1 3-Byte Addressing Mode
      2. 2.2.2 4-Byte Addressing Mode
      3. 2.2.3 State Retention Behavior
    3. 2.3 Boot Compatibility Considerations
      1. 2.3.1 Boot ROM Expectations
      2. 2.3.2 Addressing-Mode Mismatch Mechanism
      3. 2.3.3 Start-Up Impact
    4. 2.4 Example Start-Up Investigation
      1. 2.4.1 External Failure Symptoms
      2. 2.4.2 Boot ROM Log Analysis
      3. 2.4.3 Memory Verification Using CCS
      4. 2.4.4 Image Comparison
      5. 2.4.5 QSPI Bus Analysis
      6. 2.4.6 Root Cause Confirmation
    5. 2.5 Debug Methodology
    6. 2.6 Mitigation and Design Recommendations
      1. 2.6.1 Preferred Solution: Flash Reset Synchronization
      2. 2.6.2 Alternative Solution: Driver-Level Mitigation
      3. 2.6.3 Applicability of the 0x6C Mitigation
      4. 2.6.4 Design Constraints for Large-Capacity Flash Applications
  6. 3Summary
  7. 4References

2.4.5 QSPI Bus Analysis

QSPI Bus Capture During Start-Up Figure 2-6 QSPI Bus Capture During Start-Up

Logic-analyzer captures confirmed that:

  • The Boot ROM transmitted command 0x6B using a 3-byte address phase.
  • The Flash device remained in 4-byte addressing mode.
  • Flash data output began one byte later than expected.
  • The observed displacement matched the offset identified during CCS memory inspection.

This correlation provided direct evidence that the authentication failure originated from Flash-read corruption rather than certificate-generation or image-signing errors.