The only thing is don't  try using it as Ram because of the limited write 
cycles..EEprom has an quark about it has where Fram don't...Fram can be used 
much the same as ram but don't use it as such ...Use a Function or a Sub to 
access it.. Or you will wear it out ...
  EEROM has a limited number of write cycle in its lifetime but unlimited 
reads are allowed.
  ie only write cycles wear it out. Limits are typically in the 10,000 to 
1,000,000 cycles range BUT this can vary greatly with application and data 
sheets should be consulted carefully.

  FRAM has a significantly higher number of write cycles than EEROM BUT read 
cycles affect lifetime just as much as write cycles. ie both read and write 
cycles wear it out. Allowed cycles can be 10 to 100 times higher than for 
EEROM BUT because read cycles also cause wear-out the lifetime can occur 
very rapidly. eg a 10 million cycle memory accessed once a second for read 
or write will wear out in about 3 months. Every millisecond access dies in 
about 3 hours.

  Re-writeable memory used for program storage (often but not always Flash) 
usually has a much lower maximum number of write cycles - often only about 
1,000.

  With both EEROM and FRAM, lifecycles *MAY* be on a per cell basis 
(depending on design), so spreading accesses across a range of memory cells 
may usefully extend lifetimes.

  Data sheets should be carefully consulted to understand wear-out 
mechanisms for YOUR memory product.



          Russell McMahon 
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