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Number of write cycles

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I have ZNet 2.5 XBee modules. They contain the EM250 SoC from Ember. In the XBee manual it cautions about writing to the module too much as the EM250 has a limited # of writes.

How many writes are too many?
asked Aug 12, 2009 in ZigBee PRO Featureset (and legacy ZNet 2.5) by mchargis New to the Community (7 points)

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5 Answers

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The EM250 integrates 128kB of Flash memory. The Flash cell has been qualified for a data retention time of
>100 years at room temperature. Each Flash page size is 1024 bytes and is rated to have a guaranteed 1,000
write/erase cycles.
answered Aug 12, 2009 by JayF New to the Community (12 points)
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Thank you. The way it is written it sounded like my doctor saying don't have "too much" caffeine without defining what "too much" means
answered Aug 12, 2009 by mchargis New to the Community (7 points)
0 votes
Here is the source if you need more info:
http://www.ember.com/pdf/120-0082-000_EM250_Datasheet.pdf
answered Aug 12, 2009 by JayF New to the Community (12 points)
0 votes
1000 write cycles is plenty for program flash, but less
so for parameter flash.

Is it known whether node parameters (written with ATWR) are
in program flash or Simulated EEPROM? One supposes that
the latter would have a much larger write-cycle capacity,
but the "sparingly" warning appears in the ATWR description.

This is significant since (as near as I can tell) the Dia
XBee configurator does an ATWR every time Dia starts up.
answered Nov 19, 2009 by bmckenney New to the Community (1 point)
0 votes
I've wondered this myself about the way DIGI DIA always sets and writes the parameters. With the warning in the hardware document this seems to be a very bad practice. It would not be difficult to do 1000 write cycles during network development.

I think DIGI DIA should first read the devices parameters and only issue an ATWR command if a parameter needs changing.
Isn't this the reason for having the parameters in non-volatile memory, so that they don't need to be written each time the module is initialized!
answered Nov 19, 2009 by waltr Community Contributor (85 points)
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