Re: refreshing RAM from EPROM

I'm working on a project where they implemented a data store in

> EEPROM and a copy of it in RAM. The RAM copy is updated all the time > and a low priority task writes it back to EEPROM. > There is also a task that eery once in a while copies back from > EEPROM to it's RAM shadow. I can't understand why someone would want > to do that - if it is to overcome corruption, isn't it better to > reset the system ? Otherwise, you can get real messy... > Can you think of some benefit from this policy?

are you sure about the copy back to ram? Icould see where once in a while you would compare ram vs eeprom to be sure everything is still in working order, but copy?

Reply to
rwiehler
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Not really, no.

I designed and implemented a system that stores configuration data in a EEPROM. The EEPROM is read once at reset into a RAM buffer. All of the system's read and write accesses are from and to the RAM buffer. A three second timer is started any time that the RAM buffer is written and, when that timer expires, the EEPROM is updated. This supports a compromise between wearing out the EEPROM with excessive writes and the desire to keep the EEPROM up to date.

HTH

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          Michael Kesti            |  "And like, one and one don't make
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Michael R. Kesti

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