KEA64 P-Flash emulated EEPROM dead sector issue

[enwei]

Hi,

   as we know, KEA64 and KEA128 has no on-chip EEPROM, and user can use its P-Flash to emulate EEPROM(it's usually called EEE), and we provide the EEE driver:

EEPROM emulation driver for KEA128 and KEA8 (REV 1.0.0)

I'm using this driver recently, and I found there is no dead sector(the ECC error handle and data lost process when suddenly power down when erase/program the P-Flash) handle, dose anyone have such experience can share us for reference?

thanks!

Enwei Hu

[kerryzhou]

Hi E.W. Hu,

In the practical usage, customer can combine the software design the hardware design together.
Use the LVD function together, if the power down event happens, in the LVD interrupt function check whether the emulate eeprom data wrote is finished.
If it is not finished, you can write it again in the interrupt.
But just use the LVD function in the software is not enough, you must make sure the time from enter LVD interrupt to 2.7v is enough to write your unfinished data.
This time you can calculate it by the flash program time(find it from the datasheet), the detail time which power down to 2.7V in the board also can be designed by the hardware, you can add a larger capacitor guarantee it.
More details, you need to do the testing on your own board.

Wish it helps you!

Have a great day,
Kerry

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[enwei]

Hi Kerry,

Thanks for your suggestion, but we must disable the CPU interrupt when launching the P-Flash erase/program command to avoid the read while read of Flash, so I do not think the LVD interrupt will help expect we move both interrupt vector table and all perpherals interrupt ISR into SRAM, it is right?

Enwei Hu

[kerryzhou]

Hi E.W.

    Yes, you are correct.

    If you want to use this method, you need to copy all the ISR vector table and the launch flash command in the SRAM.

Have a great day,
Kerry

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