I'm confused, and I hope you can help me figuring out, what I misunderstood. I am not an electronics engineer, so bear with me :)
I have a chip, from the engine control unit of a Toyota Yaris Verso from year 2000, with the following print:
ATMEL010 25020NB 9D3203C
I have not been able to find a datasheet. And that really surprises me. I did find one for At25020B, but not for one with the NB suffix. Why would Atmel make a chip and not publish the datasheet?
First of all, from what I can find, the Atmel AT25 series are all EEPROM (source). So this chip should be an EEPROM. Am I right?
I looked up, what the suffices mean and found the following (source: Explanation of Atmel’s Part Number Code). B means some kind of military compliance. The N says something about the package:
N = Leadless Chip Carrier, One Time Programmable
I think the N in some cases mean "Leadless Chip Carrier" and in some cases "One Time Programmable", since they are not related. Do you agree?
Looking at the picture, it obviously has 8 leads, so it is not leadless, and thus N must mean one-time-programmable. Do you agree?
As far as I understand the EEPROM technology it is by definition erasable/rewritable.
Is this really a one-time-programmable (and therefore not erasable/rewritable) EEPROM? Or what have I misunderstood? :)
The background for even asking is because I have not had luck with communicating with the chip. A friend, who is an experienced tingler tried to with Bus Pirate and command line tool flashrom, without luck.