SPRACC0A November   2017  – November 2020 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1

 

  1.   Trademarks
  2. 1 Introduction and Scope
  3. 2 SRAM Bit Array
  4. 3 Sources of SRAM Failures
    1. 3.1 Manufacturing Defects
      1. 3.1.1 Time Zero Fails
      2. 3.1.2 Latent Fails
    2. 3.2 Circuit Drift With Usage
    3. 3.3 Circuit Overstress
    4. 3.4 Soft Errors
      1. 3.4.1 Radioactive Events
      2. 3.4.2 Dynamic Voltage Events
      3. 3.4.3 Summary of Error Sources
  5. 4 Methods for Managing Memory Failures in Electronic Systems
    1. 4.1 Start-Up Testing
    2. 4.2 In-System Testing
    3. 4.3 Parity Detection
    4. 4.4 Error Detection and Correction (EDAC)
    5. 4.5 Redundancy
  6. 5 Comparisons and Conclusions
  7. 6  C2000 Memory Types Example
    1. 6.1 TMS320F2837xD
  8. 7 Memory Types
    1. 7.1 Dedicated RAM (Mx and Dx RAM)
    2. 7.2 Local Shared RAM (LSx RAM)
    3. 7.3 Global Shared RAM (GSx RAM)
    4. 7.4 CPU Message RAM (CPU MSGRAM)
    5. 7.5 CLA Message RAM (CLA MSGRAM)
  9. 8 Summary
  10. 9 References
  11. 10Revision History

4.1 Start-Up Testing

Testing the SRAM at start-up does not address the three above listed perspectives. However, there is significant value added in testing the SRAM at start-up even if it is not possible to test while the system is operational.

There is a proverb in the semiconductor industry that the second worst thing you can do to a system is power it down, with the very worst thing being power up. This is because the voltage and current swings during power up and power down of a system (or system component) cannot be fully managed. The devices are designed to work with this, but should a destructive power event occur, it is more likely to occur during power up/down. Therefore, testing the SRAM at power up addresses the most likely points where the circuit will be damaged.

Additionally, SRAM is easier to test at start up because there is no context to save and restore because the system context has not yet been loaded. SRAM testing by the embedded CPU takes a lot of CPU cycles and is not as easily or as effectively done while sharing the CPU resources with the system operation.