SPRADC1 june   2023 DRA829J , DRA829J-Q1 , DRA829V , DRA829V-Q1 , TDA4VM , TDA4VM-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Different Types of Memories on the TDA4VM
  5. 2Memory Overview and Intended Usage
    1. 2.1 PSROM
      1. 2.1.1 Typical Use Cases
    2. 2.2 PSRAM
      1. 2.2.1 Typical Use Cases
    3. 2.3 MSMC RAM
      1. 2.3.1 Typical Use Cases
      2. 2.3.2 Relevant Links
    4. 2.4 MSRAM
      1. 2.4.1 Typical Use Cases
    5. 2.5 ARM Cortex A72 Subsystem
      1. 2.5.1 L1/L2 Cache Memory
      2. 2.5.2 L3 Memory
      3. 2.5.3 Relevant Links
    6. 2.6 ARM Cortex R5F Subsystem
      1. 2.6.1 L1 Memory System
      2. 2.6.2 Cache
      3. 2.6.3 Tightly Coupled Memory (TCM)
      4. 2.6.4 Typical Use Case
      5. 2.6.5 Relevant Links
    7. 2.7 TI's C6x Subsystem
      1. 2.7.1 Memory Layout
      2. 2.7.2 Relevant Links
    8. 2.8 TI's C7x Subsystem
      1. 2.8.1 Memory Layout
      2. 2.8.2 Relevant Links
    9. 2.9 DDR Subsystem
      1. 2.9.1 Relevant Links
  6. 3Performance numbers
    1. 3.1 SDK Data Sheet
    2. 3.2 Memory Access Latency
  7. 4Software Careabouts When Using Different Memories
    1. 4.1 How to Modify Memory Map for RTOS Firmwares
    2. 4.2 DDR Sharing Between RTOS Core and HLOS
    3. 4.3 MCU On-Chip RAM Usage by Bootloader
    4. 4.4 MSMC RAM Default SDK Usage
      1. 4.4.1 MSMC RAM Reserved Sections
      2. 4.4.2 MSMC RAM Configuration as Cache and SRAM
    5. 4.5 Usage of ATCM from MCU R5F
    6. 4.6 Usage of DDR to Execute Code from R5F
  8. 5Summary

4.6 Usage of DDR to Execute Code from R5F

Upon PORz, R5F's default MPU (memory protection unit) is not setup to have execute permissions for DDR, see Table 7-1 of the Arm Cortex R5F TRM.

To execute code from DDR, the MPU needs to be re-configured in the MPU init (__mpu_init()) function from the startup code, giving executable permissions to DDR mapped to 0x8000_0000. Once this is done, code can be executed from DDR.