Difference between flash and eeprom

[anoop kr]

What is the main difference between FLASH memory and EEPROM in microcontrollers....In AT89C51 micro datasheet they tells that they are
using non volatile flash technology.does these two are differ only in technology..???please help me... i am so confused with this..:-?

 

[alexan_e]

The flash memory is a non volatile memory where the code is stored, the code that is executed, you can't write to the flash memory from your code, any change you do to variables is stored in RAM and is lost when the mcu restarts.
The eeprom is a small non volatile memory space that is available to the user to store any data that should be preserved between restarts, you can store/restore/delete data there at any time from your code or even from an external programmer (usefull to read/write specific initial setting).
The eeprom usually stores some settings that are changed while the code is executing and should be preserved.

Alex

 

[Pheetuz]

What Alex has said is completely true apart from under certain condition with certain processors where it is possible to write to the flash memory in normal program operaton, this makes applications such as bootloaders possible.

Fundamentally they are both the same apart from an EEPROM has a higher voltage source built in so that the data can be overwritten in normal program operation.


If your interested then try looking up floating gate mosfets on wikipedia or something, it quite an interesting topic.

Pete

 

[Ehsan85]

see this may help you.
https://wiki.answers.com/Q/What_is_the_difference_between_flash_memory_and_EEPROM

 

[alexan_e]

see this may help you.
https://wiki.answers.com/Q/What_is_the_difference_between_flash_memory_and_EEPROM

The question is specific to the internal eeprom and flash memory of a microcontroller so the article you point to is irrelevant.

 

[wb2008ie]

what pheetuz has said is completely ture on the ARM Cortex M3 core ,for example luminary bought by TI.