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LockedEEPROM retention

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2004/11/29 01:44:02 (permalink)
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EEPROM retention

For PIC18Fx520 (and other PICs), a Flash/Data EEPROM retention > 40 years is stated.

But according to page 82, section 7.8 in the datasheet, refresh is required for infrequently changing EEPROM parameters.

Can anyone explain this apparent decontradiction to me?

/Henrik
#1

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    ric
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    RE: EEPROM retention 2004/11/29 03:24:54 (permalink)
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    This has been discussed several times on this forum.
    If you never write to the EEPROM, it will all be retained for > 40 years.

    If you frequently write to only some of the locations, this will slowly degrade the other locations which are never re-written.

    The solution is to re-write all locations occasionally.

    I also post at: PicForum
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    RE: EEPROM retention 2004/11/29 05:16:50 (permalink)
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    Thanks! Would be nice if Microchip would include this into the datasheet.

    I apologize for repeating a previous question; initially, I tried searching for similar subjects, without any luck.

    /Henrik
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    ric
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    RE: EEPROM retention 2004/11/29 05:46:11 (permalink)
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    I tried searching for similar subjects, without any luck.


    By default, search only looks over the past 30 days.
    This might be useful if you want to find something you remember seeing recently.
    Otherwise, ALWAYS extend the search to include all posts.

    I also post at: PicForum
    Links to useful PIC information: http://picforum.ric323.co...opic.php?f=59&t=15
    NEW USERS: Posting images, links and code - workaround for restrictions.
    To get a useful answer, always state which PIC you are using!
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    RE: EEPROM retention 2004/11/30 01:21:25 (permalink)
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    Thanks again, I failed to notice that search setting!

    Previous posts indicate that the critical number of writes appear to be in the order of millions, before neighboring cells are affected.

    Furthermore, some suggest that it might be an advantage to isolate frequently changing EEPROM cells with cells that are not used. Can this be confirmed?

    /Henrik
    #5
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