Hi Ziv,
I am sorry, my experience with S32K144 are limited. However, I know a little bit more about the similar system on S12XE. So, my answer may be slightly more generic.
The emulated EEPROM is a special feature of flash controller. It uses FlexRAM (4kB) and FlexNVM (64kB) block for emulating 4kB of EEPROM feature. We write and read FlexRAM memory range and updated data are stored into FlexNVM on the background as records (index+value). When MCU reset, the EEE state machine will update FlexRAM memory from latest FlexNVM records.
The Flash controller offers some small variability (in compare with S12XE) in optional configuration EEPROM and RAM/Flash size. See Table 32-41. Valid emulated EEPROM data set size codes : 4kB FlexRAM configurations and Table 32-43. Valid FlexNVM partition codes : 256KB, 512kB and 1MB configurations with 64kB FlexNVM in RM.
However the amount of FlexNVM memory used for emulated EEPROM backup (see Figure 32-3). In order to achieve specified w/e cycle endurance, the emulated EEPROM backup size must be at least 16 times the emulated EEPROM partition size in FlexRAM. From this point of view, it seems that different settings that EEESIZE=0x02, DEPART=0x08(0x04) have not very big sense.
When you will use a smaller part of FlexNVM for EEE, the amount of usable EEEPROm should be also limited (For example: we should not use more than 2KB for EEPROM when FlexNVM for EEE is just 32kB). The remains from FlexNVM (bottom part of FlexNVM) may be used as data flash (erased/programmed by Flash controller commands).
The FlexNVM partition example code is already part of SDK.
I hope it helps you.
Have a great day,
Radek
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