SWRA657 June   2020 CC3100 , CC3200

 

  1.   SimpleLink Wi-Fi CC3100, CC3200 Serial Flash
    1.     Trademarks
    2. 1  Introduction
    3. 2  How File System Content Gets to the Serial Flash
    4. 3  File System Guidelines
    5. 4  User File Mathematics
    6. 5  System and Configuration Files
      1. 5.1 Description
      2. 5.2 Memory Consumption
        1. 5.2.1 CC3200 Use Case
        2. 5.2.2 Host Driver Mapping
        3. 5.2.3 Minimum Flash Size
    7. 6  Implementing File System Features From Host Processor
      1. 6.1 Overview
      2. 6.2 File Listing
        1. 6.2.1 Requirements
        2. 6.2.2 Procedure
      3. 6.3 Free/Occupied Space
        1. 6.3.1 Requirements
        2. 6.3.2 Procedure
      4. 6.4 File Appending
        1. 6.4.1 Requirements
        2. 6.4.2 Procedure
    8. 7  Factors to Consider in Designing With Serial Flash
      1. 7.1 Serial Flash Vendor and Part Number Selection
      2. 7.2 Supported Flash Types
      3. 7.3 Frequent Write Operations
        1. 7.3.1 Serial Flash Access by the Wi-Fi System"
        2. 7.3.2 Seral Flash Access by the WiFi System
          1. 7.3.2.1 System Files
          2. 7.3.2.2 User Files
      4. 7.4 Sudden Power Off (power removal during a write/erase phase)
        1. 7.4.1 Battery Powered Systems
        2. 7.4.2 Line Powered Systems
    9. 8  Design Recommendations for Ensuring the Integrity of the Power Supply to the Serial Flash
      1. 8.1 Overview
      2. 8.2 Key Points
      3. 8.3 Brown-Out Mitigation Techniques for New Self-Hosted CC3200 Designs
    10. 9  Recommended Best Practices
    11. 10 Implications of Data Integrity Compromise to CC3100/CC3200
      1. 10.1 Recovery
    12. 11 References

7.4 Sudden Power Off (power removal during a write/erase phase)

All systems using serial flash are vulnerable to the effects of sudden power removal. As noted in most serial flash data sheets, data corruption may occur if the power is removed while a write/erase operation is in progress. This can happen if the system operating voltage goes below Vmin of the serial flash (2.3 V typical) before the erase/write operation is completed. Figure 5 shows a typical scenario.

swra657-serial-flash-corruption-during-a-sudden-power-off-event.pngFigure 5. Serial Flash Corruption During a Sudden Power Off Event

This scenario may occur in battery or line powered end equipment.

  • Battery Powered Products: Removal of battery from the product without a soft shutdown
  • Line Powered Products: Electrical supply failure or sudden unplugging without a soft shutdown

The sections below explain how the potential for serial flash corruption can be minimized in both types of end equipment.