SFL: Persistent memory

Persistent memory is storage that will keep its content even when the RTCU is powered down.
By using the SaveString/LoadString and SaveData/LoadData, it is possible to save and load strings/data from a specified location in the persistent memory.

The persistent memory of the RTCU devices is implemented by using two different memory technologies. The largest part of persistent memory uses FLASH technology. The FLASH technology has a limitation in that it can only be written a finite number of times. If written more than that, the FLASH memory will no longer be stable, which then results in loss and corruption of data. To overcome this problem, the RTCU devices also contain FRAM-based memory, which does not have any limitations with respect to the number of times it can be written to.

The FLASH-based persistent memory is composed of entries with a maximum length of 255 bytes. Each entry can be rewritten a minimum of 100,000 times before flash wear-out will occur.

For FRAM-based persistent memory, there up to 100 separate entries available - each also with a maximum length of 255 bytes.

	•SaveString	Saves a string to persistent FLASH memory.
	•LoadString	Loads a string from persistent FLASH memory.
	•SaveData	Saves a block of memory to persistent FLASH memory.
	•LoadData	Loads a block of memory from persistent FLASH memory.
	•SaveStringF	Saves a string to persistent FRAM memory.
	•LoadStringF	Loads a string from persistent FRAM memory.
	•SaveDataF	Saves a block of memory to persistent FRAM memory.
	•LoadDataF	Loads a block of memory from persistent FRAM memory.
	•SaveStringX	Saves a string to persistent extended FLASH memory.
	•LoadStringX	Loads a string from persistent extended FLASH memory.
	•SaveDataX	Saves a block of memory to persistent extended FLASH memory.
	•LoadDataX	Loads a block of memory from persistent extended FLASH memory.
	•GetFlashXSize	Gets the size of the persistent extended FLASH memory.