K64FX512 Power Cycle during write to FlexNVM or FlexEEPROM

[peterbrenner]

Hi all,

we are using a MK64FX512 controller where some importand data like network settings should be stored twice. One copy is planned to be in the EEPRM area beginning at 0x1400_0000 and one copy beginning at 0x1000_0000. The amount of the data is about 512Byte. The upcomming question is now is there any influence between the two memory areas due to the internal handling? E.g. if the data in the NVM gets corrupt due to a power cycle during writing are the data in the EEPROM area still ok and vice versa?

Thanks in advance

Peter

[info27]

Hi Xiangjun Rong,

Hi all,

Thanks for your reply. Peter and me working together on the same project, so I get back.

I guess there is a missunderstanding and we do not want to write at the same time. Our concerns are regarding the potential influence of the different memory areas in case of an write access during the power down phase of the Kinetis device. In generall it is critical for non volatile devices (flash or EEPROM) to write while the power supply is switched off and it may result in unexpected behaviour/writing over sectors etc.

Question 1: Is it possible to influence/change/destroy data in the EEPROM area (start at 0x1400_0000) by writing the data flash area (start at 0x1000_0000) - we are using a mixed mode and use data flash in FlexNMV and EEPORM in or as FlexRAM as shown in the screen shot below - during power down phase of the Kinetis device.

Question 2: Is it possible to influence/change/destroy data in the data flash area (0x1000_0000) by writing the EEPROM area (0x1400_0000) - vise versa to question 1 - during power down phase of the Kinetis device.

Question 3: Is it possible to influence/change/destroy data in the flash area (start at 0x000_0000) by writing the data flash area (0x1000_0000) and/or by writing the EEPROM area (0x1400_0000) during power down phase of the Kinetis device.

Many thanks in advance.

Regards,

Thomas Grebenz

[xiangjun_rong]

Hi, Thomas,

As you know that erasing/programming operation of flash does not require external high voltage, but

Internal high-voltage supply generator for flash memory program and erase operations is required, we use internal charger pump to implement it. In power off process, the supply voltage decreases, maybe the internal charger pump can not works, it may take effect on the programming/erasing.

BR

xiangjun Rong

[xiangjun_rong]

Hi, Peter,

I think it is okay to write the same data array to FlexNVM and EEPROM. It seems that you want to write EEPROM and FlexNVM at the same time, if it is the case, i think there is issue, because when you write EEPROM, there is internal mechanism to write FlexNVM. If you write FlexNVM, after the writting is over, write EEPROM, it is okay.

Hope it can help you

BR

Xiangjun Rong