This post talks about some basics of EEPROM and FEE.
To start with the discussion it is necessary to know what EEPROM stands for. EEPROM stands for Electrically Erasable PROM. Where PROM means Programmable Read only memory. The very fact that we are highlighting the Electrically Erasable means that there are other methods to erase the PROM. I leave it to the reader to find out what these are and leave as a comment.
Why do we need it?
In any system there are some set of parameters that need to be remembered through power cycles and can/may change between power cycles. An example....Well Your monitor settings ( i.e. the brightness contrast etc that you do on your monitor) is remembered through power cycles even if you connect the monitor to another PC or whatever. One of the places to store this could be the EEPROM.
What does this mean?
To write to the EEPROM i should be able to erase it and then rewrite it. Also it should be capable of being written several times ( maybe a few lakh times). Also, it should have data retention capacity. i.e if i write it today and check after say some 10 years the data should be same in the absence of any power.
What is FEE then?
As you can see some of the properties of EEPROM are held by the flash memory also. Like i can write into the Flash memory electrically, it can retain information across power cycles, it can be written multiple times. However, the biggest different is that the flash technology ensures that it can be written only in huge chunks like 64 or 128 bytes. Also, the life of the Flash memory is much lesser than the EEPROM. On the other hand the best part is that it costs much less than the EEPROM.
So FEE which stands for Flash Emulated EEPROM is basically a method of emulating the behaviour of the EEPROM using the Flash memory. This means if a Flash memory has 10000 write cyles, i should make it some how work as if it is 100,000 write cycles ( like in case of EEPROM). Also, i should provide somehow the capability of writing a single word/ single byte as available in the EEPROM.
In short if i have FEE then the application should feel as if it is having EEPROM....
How to do this ? Well that is for another post....
Please leave your comment. You can subscribe to this blog by using the links under "Subscribe" section.
To start with the discussion it is necessary to know what EEPROM stands for. EEPROM stands for Electrically Erasable PROM. Where PROM means Programmable Read only memory. The very fact that we are highlighting the Electrically Erasable means that there are other methods to erase the PROM. I leave it to the reader to find out what these are and leave as a comment.
Why do we need it?
In any system there are some set of parameters that need to be remembered through power cycles and can/may change between power cycles. An example....Well Your monitor settings ( i.e. the brightness contrast etc that you do on your monitor) is remembered through power cycles even if you connect the monitor to another PC or whatever. One of the places to store this could be the EEPROM.
What does this mean?
To write to the EEPROM i should be able to erase it and then rewrite it. Also it should be capable of being written several times ( maybe a few lakh times). Also, it should have data retention capacity. i.e if i write it today and check after say some 10 years the data should be same in the absence of any power.
What is FEE then?
As you can see some of the properties of EEPROM are held by the flash memory also. Like i can write into the Flash memory electrically, it can retain information across power cycles, it can be written multiple times. However, the biggest different is that the flash technology ensures that it can be written only in huge chunks like 64 or 128 bytes. Also, the life of the Flash memory is much lesser than the EEPROM. On the other hand the best part is that it costs much less than the EEPROM.
So FEE which stands for Flash Emulated EEPROM is basically a method of emulating the behaviour of the EEPROM using the Flash memory. This means if a Flash memory has 10000 write cyles, i should make it some how work as if it is 100,000 write cycles ( like in case of EEPROM). Also, i should provide somehow the capability of writing a single word/ single byte as available in the EEPROM.
In short if i have FEE then the application should feel as if it is having EEPROM....
How to do this ? Well that is for another post....
Please leave your comment. You can subscribe to this blog by using the links under "Subscribe" section.
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