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.

danielmartynek_0-1694516246273.png

Regards,

Daniel

[CKing]

Hi @danielmartynek 

I see pre-erasing in AN11983. 

CKing_0-1694570075123.png

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.

danielmartynek_0-1695201040666.png

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