SDAA362 June   2026 TDA4VE-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Runtime Code Overlay Background
    1. 2.1 Memory Architecture of TDA4x
    2. 2.2 Challenges of Static Code Allocation
    3. 2.3 Why Runtime Code Overlay?
  6. 3Runtime Code Overlay Methodology
    1. 3.1 Overview
    2. 3.2 Resident Runtime
    3. 3.3 Overlay Payload package
    4. 3.4 Shared SRAM Overlay Region
    5. 3.5 Runtime Overlay Sequence
  7. 4Runtime Code Overlay Architecture
    1. 4.1 Software Architecture
    2. 4.2 Overlay Package Format
    3. 4.3 Memory Layout
    4. 4.4 Runtime Image Loading
    5. 4.5 Runtime Execution
  8. 5Demo Implementation
    1. 5.1 Software Organization
    2. 5.2 Overlay SRAM Configuration
    3. 5.3 Payload Generation
    4. 5.4 Payload Loading and Execution
    5. 5.5 Build Configuration
  9. 6Runtime Code Overlay Verification
    1. 6.1 PayloadA Execution
    2. 6.2 PayloadB Execution
    3. 6.3 PayloadC Execution
    4. 6.4 Shared SRAM Overlay Slot Reuse
    5. 6.5 Complete Runtime Verification
  10. 7Summary
  11. 8References

7 Summary

This application note presented a runtime code overlay methodology using eMMC FATFS on a TI TDA4x MCU R5F core.

The implementation stores executable payloads as files in the eMMC User Data Area (UDA) and dynamically loads them into a reusable SRAM execution region at runtime. Because eMMC is accessed as a block storage device and does not support direct code execution, payloads are read through the FATFS layer, loaded into the SRAM overlay region, and executed through a runtime overlay mechanism.

The demonstrated framework consists of a resident runtime, an overlay loader, and executable payload packages. Using this framework, multiple payloads were successfully loaded and executed from eMMC FATFS while sharing a single SRAM overlay slot.

Verification results confirmed FATFS-based payload access, runtime image loading, SRAM-based execution, function pointer invocation, and repeated reuse of the same execution region. The methodology provides a practical approach for storage-backed executable loading and runtime feature expansion on TI TDA4x MCU R5F platforms.