This is my weekend toy, a Spansion/Cypress fl256saif00 (S25FL256S), a 32MB SPI module. This chip is salvaged from a Cisco EPC3928 Docsis 3.0 Modem Router (2012).
The (first) challenge was to be able to remove it from the donor PCB without damage it and to solder it on a breakout board, just for practice. This seems to be successful so far, nice result. Pretty good for just a first-timer. Because of this result, I just thinking of reusing it with use of a MCU.
I have downloaded the datasheet (it is huge!) and also found a library to create a filesystem on it. However, there are some questions, because this chip is not new and there are several memory protection methods described in the datasheet. I cannot figure out whether it is temporary (active when used inside application) or permanent (forever). For example write protection on some memory areas. I will spend some time on it and want to know for sure, that is not unusable by protection (thus a waste of time), for example impossible to reformat and write data/files to it. It must be fun, no frustration ;-)
So my question/doubts (before I start this investigation/journey) are:
- Is it possible when it is protected to unlock the protection by reformat/clear the whole flash memory? Can I reuse it anyway?
- In the datasheet, there are several packages, except mine (see picture above). There is a 16-lead SOIC displayed that match the pins however not the size (width), is this actually the same?
The datasheets, there are two versions of the same, one branded Spansion and one branded Cypress. I have read that Cypress bought Spansion in 2015, that's the reason there are two brandnames involved. I think I must use the first one, since the IC is labeled with the brand "Spansion" and module is of a device of 2012.