How often is data transferred from RAM to EEPROM ?
In a typical embedded automotive embedded system, I believe data is only transferred from RAM to EEPROM once every key cycle, right before embedded system goes to sleep ?
Re: How often is data transferred from RAM to EEPROM ?
Normaly, we are using DB approach. It stored in RAM and only when sync operation is needed, it is updating EEPROM or more often - flash.
In my latest project I made it another way - when we read DB, it takes it directly from flash. But when we need to update it - it takes some space from RAM, put DB there, update it and then copy back to flash. This is because normally DB used in read-only mode.
Re: How often is data transferred from RAM to EEPROM ?
Hi,
how often the data is transferred depends on the software..and what data has to be stored.
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Imagine a TV set - for example.
It remembers the last viewed channel. It stores the channel number in an EEPROM.
If you never change the channel ... there is no need to transfer the (new) channel number to the EEPROM.
But if you zap through the channels, then it needs to update the EEPROM every time you change the channel.
I would remark that for typical automotive system you should also provide the ability to check the status of the power supply, have seen the instability during start of ignition particularly when the battery of the vehicle is reaching the end of its lifespan and you have to save a massive amount of data in a single sequence. Anyway, as mentioned above, each application is a distinct case.