help for eeprom

[mahmoud boroumand]

Posted on August 05, 2017 at 11:49

Hey I use stm32f0p4.

i confused  about eeprom.i readed AN2594 Applocation note but i cant undresntands i have some question about that.

1-is it trust-able to use? i don't want my data losing.

2.How much byte i can save ?

3.is it better i use external eeprom?

[S.Ma]

Posted on August 05, 2017 at 12:29

Eeprom emulation in flash is for space or cost optimisation. Otherwise, use an i2c eeprom first and when needed change to emulated one. The emulated eeprom in flash is good for low rewrite cycles, space, cost and memory access speed. External i2c eeprom have multiple size with same footprint and cycling erase write is much higher.

[Tesla DeLorean]

Posted on August 05, 2017 at 13:35

3) If this is an option, always take it

1) For a robust method, understand how the underlying Flash works/behaves, and code a solution yourself. You'll at least understand the pitfalls and limitations. I would also use NVRAM/BKPRAM, and RAM is not lost across reset unless the power is removed.

2) Review and understand the code. It, as I recall, uses a journalling method across two pages, and a verbose way of representing the data records, if I have to guess from memory, say 1/4 the size of a sector.

[mahmoud boroumand]

Posted on August 05, 2017 at 12:38

Thanks 

how can i get the size of 

emulated eeprom?

[S.Ma]

Posted on August 05, 2017 at 13:49

Approximately take the eeprom needed size then multiply it until it flash min guaranteed rewrite cycling reach your target. Say 1kbyte 1 million times with 10k cycle flash will require 100kbyte flash (in fact it will also depend on sectors)