EEP data consistency at different offset

[Catosh]

Hi all, 

I am wondering if writing data in E3prom at a given offset can corrupt or lead to data loss at another offset. 

Use case: suppose I store some metadata relevant for my application in the first K of E3prom, while the remaining bytes are used for data logging. For the sake of the discussion, let's refer to relative addresses (address 0x0 means FlexRam address + 0x0, etc).

Is it possible that a write at address 0x401 corrupts the data at address 0x0?The same states for contiguous addresses (e.g. write at 0x401 impacts data at 0x400). 

I understand that EEEprom/FlexRAM addresses are abstractions of the internal controller that maps the FlexNVM to FlexRAM, just wondering. ù

I need to be confident that flags and data relevant for my application are "safe enough" in EEEprom. 

K.R.

[danielmartynek · Accepted solution]

Hi,

The EEPROM (FlexRAM) is writable in single bytes.

If the byte at 0x401 is over-witten, it will create a record in the backup flash.

If then the byte at 0x400 is over-written, it creates another records.

Please keep in mind that the EEPROM uses the same amount of backup flash for one 8bit record as for one 16bit (or 32bit) record.

A write to 0x400 will not change (or move) the 0x401 record in the backup flash unless of course the 0x400 byte in FlexRAM is over-written as well.

BR, Daniel.