This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

peer manager flash cycling requirements

Hello, there is written that Peer Manager is using flash for storing bonding data or service configuration. Can you extend a documentation - and add description when and how many bytes the peer managers stores into flash? (for example I can imagine there can be implementation which stores configuration change only upon disconnect, or on every configuration change). We need to guarantee that our product would last for defined years under some model of maximal usage (respecting that flash has only 10K erase cycles).

Also could you add example how to calculate the flash lifetime? It can look something like this:

FDS_VIRTUAL_PAGE_SIZE = 1024 B
FDS_VIRTUAL_PAGES = 1

Thus we have (1024-2)*1 B to use. FDS will guarantee optimal flash load. (2B by page is used by Flash Data Storage (FDS) module (I think))

Example model of usage could be that user bonds a device 1 per day. And change configuration of 100 characteristics per day. Storing bondage information takes 16B. Storage new configuration takes 2B per characteristic (but takes 4B to be word aligned). For each file-record entry there is overhead of 12B. Therefore per day we need to write 16+12+(4+12)*100= 1628 B. FDS will ideally load whole 1022B. Thus we have 1022 B * 10000 eraseCycels / 1628 BytesWrittenPerDay = 6277 days = 17 years.

Note that this example is my guess - if I would be certain it is correct I would not ask for more documentation...

Parents Reply Children
No Data
Related