Knowledge Base

The DT16 has 5 types of non-volatile memory, all of which are retained when power fails.  None of them rely on the RTC battery.  Here’s an overview:

Storage AreaSizePreloadErasedWritableNon-VolatileUsesRAMStatus ReturnedEndurance
Permanent Memory13NoYesYesYesYesYes2.5 million
Shadow250NoNoYesYesYesNo320,000
NVEM064k(*1)YesReplacedNoYesNoN/AN/A
NVEM1246NoNoYesYesNoNo1 million   
NVEM34KNo   No   Yes   No   No   No   Infinite

Where:

  • Size:
    This is the size of the non-volatile area in bytes.
  • Preload:
    Indicates whether your source code can hold data that SPLat/PC can compile and download into the storage area.
  • Erased:
    Indicates what happens to the storage area when a new application is downloaded to the controller.
  • Writable:
    Indicates whether your running application can write to the storage area.  A “No” would mean only SPLat/PC can during “Preload”.
  • Non-Volatile
    Whether contents are saved when power is removed.
  • UsesRAM:
    Indicates if reading or writing to the storage area occurs to/from RAM.
  • Status Returned:
    Indicates if the area returns status information when it is read.
  • Endurance:
    Guaranteed minimum number of erase/write cycles.  Reading has no limit.

*1: NVEM0 space is shared with your application.  The combined size of both is limited to 64kB.