How does pre-erasing EEE in S32K1xx improve performance

[CKing]

Hello,

I am wondering how pre-erasing EEE in S32K1xx improves performance. Every writing EEPROM causes a programming to E-flash and a following maintenance. I don't see the time consumption can be reduced by using pre-erasing. Can you help me?

Regards

CK

[danielmartynek]

Hi @CKing,

What do you mean by pre-erasing?

The Program Partition command FTFC command erases the FlexNVM.

EFlash is then all 0xFF, and it is not accessible to the user.

Regards,

Daniel

[CKing]

Hi @danielmartynek 

I see pre-erasing in AN11983. 

Regards,

CK

[danielmartynek]

Hi @CKing,

There is a difference in the execution time for the writes depending on whether these are writes to new erased FlexRAM locations or updates of existing records.

It has been confirmed that we can pre-erase (or invalidate) an existing record by writing 0xFF to it.

Then, a subsequent write to this location is considered to be a new write to an erase location instead of an update.

Keep in mind that erasing the FlexRAM location takes some time too, our tests shows ~200us (32b write on S32K118).

If you want to store more records quickly, consider using the Quick write mode.

Regards,

Daniel