EEPROM Write Cycles

My question is “What exactly is a write/erase cycle?”

In the EEPROM.write() documentation it notes “The Atmega 168 datasheet says that EEPROM memory has a specified life of 100000 write/erase cycles…”

Is a write/erase cycle specific to one of the 512 available locations? I.E. I can write 100,000 times to location 0 before it burns out and is unavailable, but other locations are still useable.

OR

Is the write/erase cycle applied to the EEPROM as a whole? I.E. I can only write to EEPROM 100,000 times period no matter what location is written to.

This may sound trivial, but my application involves score keeping, so the data changes rapidly, and it needs to be stored in a non-volatile location so that it can be downloaded later and won’t be lost if the unit is accidently turned off. So if the lifespan is location specific I’ll have several years worth of writing/erasing the data before a location burns out, but if it’s the other way around the whole EEPROM could be burned out in a couple of months.

Also I found a link to the AMTEL datasheet posted on the AVR Freaks website, and it also shows that the flash memory only has a 10,000 write/erase cycle lifetime so if I can’t use the EEPROM I wouldn’t be able to use the flash either. I’ve found the infomation in the playground on using an SD Card and have checked out Libelium’s module, but are there other, better possiblities that you would suggest if the EEPROM won’t work?

Thanks to All
KJ

Is the write/erase cycle applied to the EEPROM as a whole? I.E. I can only write to EEPROM 100,000 times period no matter what location is written to.

It’s an write erase cycle, so it applies to a single location.

Some applications implement what is known as “ware levelling”, this spreads out writes across the address space to prevent the burn out of one specific location.

Not wanting to be accused of trying to teach a grumpy_mike to suck eggs, but I believe he meant “wear leveling”. :slight_smile:

–Phil.

but I believe he meant “wear leveling”

Indeed I did. :wink:
That’s what comes of being dyslexic and in a hurry. I knew it was wrong but couldn’t get the spell checker to offer any alternatives.

Note while I am dyslexic now when I was at school in the 50s / 60s I was just thick. :slight_smile:

Note while I am dyslexic now when I was at school in the 50s / 60s I was just thick.

I shudder to think how many brilliant minds were tarred with that brush–at least some things are a little more enlightened now.

–Phil.

That’s fabulous news. Thanks for the info!