EEPROM Endurance, and fitness for a task

[Gandledorf]

Atmel promises that their EEPROM will endure at least 100,000 write/erase cycles. I know in practice they tend to last longer, but by how much? One thing I am wondering is this: Would it be ok to use EEPROM to store some state variables between system boot, so if for some reason I suffer a brown out, power failure, or other condition, I can restore system state from the reset vector, rather than start fresh?

 

[bmcculla]

There are various methods to increace EEPROM life. The 100,000 writes applies to a single memory location. If you use the EEPROM like a circular buffer- each time you write your data you write to a new memory location and use a indicator byte to mark the current data. This allows you to use the write endurace for all the memory locations in the EEPROM.

Check out Ramtron if you need higher endurance. They make non-volatile magnetic ram that they claim has unlimited endurance. They will send samples too.

Your method of saving CPU state should work provided you can detect when you are loosing power and back up your state

Brent