SDAA376 August   2026 DRA821U-Q1 , DRA829J-Q1 , DRA829V-Q1 , TDA4AH-Q1 , TDA4AL-Q1 , TDA4AP-Q1 , TDA4APE-Q1 , TDA4VE-Q1 , TDA4VH-Q1 , TDA4VL-Q1 , TDA4VM , TDA4VM-Q1 , TDA4VP-Q1 , TDA4VPE-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Why Keywriter is Needed
    2. 1.2 What is Keywriter
  5. 2Keywriter Certificate Blob
    1. 2.1 Certificate Generation Overview
  6. 3Production Deployment Methods
    1. 3.1 OSPI Boot Method
    2. 3.2 eMMC Boot Method
    3. 3.3 eMMC Boot with DFU Backup Method
    4. 3.4 JTAG/Development Boot Method
    5. 3.5 RGMI Ethernet Boot Mode
  7. 4Updates in the Field
    1. 4.1 SWREV (Software Revision)
    2. 4.2 KEYREV (Key Revision)
  8. 5Common Debugging Steps
    1. 5.1 Dry-Run Testing
    2. 5.2 Package Requirements
    3. 5.3 eFuse Programming Setup
    4. 5.4 Verifying Programming Results
    5. 5.5 Boot Failure Troubleshooting
    6. 5.6 Trace Collection Without Wakeup UART
  9. 6Summary
  10. 7References

6 Summary

This application note has provided a comprehensive overview of keywriter deployment strategies for secure device provisioning in production environments. Multiple deployment methods are available to accommodate different production scenarios, from automotive and industrial applications using OSPI boot to high-volume consumer electronics using eMMC boot.

Engineers must select the appropriate deployment method based on their specific production requirements, volume, and infrastructure. Proper understanding of certificate generation, verification processes, and common debugging steps verifies successful implementation and troubleshooting of keywriter operations in real-world environments.