One of the requirement for my project is to log diagnostic data periodically over a period of time.
Controller used is STM32F405xx, LQFP64. As it does not have the on chip EEPROM, I want to interface (via SPI) externally.
As per my customer requirement, Diagnostic data and raw data to be logged for every 20 minutes. For one year backup, I need 6.727Mbit (each data set 32 bytes) and write cycles are 26280.
I found EEPROM from ST – “M95M02-DRMN6TP”. Size is only 2Mbits and cost is around $1.5
Even for 6 months data backup also, this is very high cost (>$3) solution for target price of product.
There are other type memories – NAND flash/NOR Flash which are very cheap. Endurance and Retention time are very less than EEPROM, but looks feasible for my requirement.
- Are there any other dis-advantages of Flash memory?
- Is there any low cost solution from ST products? Preferably <$1.
I have read lot of material from on-line, but couldn’t able to conclude. Kindly suggest.