FDS lifetime

[Challen]

Hi, I use SDK13.1 FDS example and have some questions about that. Is there any influence about the lifetime of Flash when i use FDS function to write and delete the records.If it has,how to calculate the lifetime of Flash.Thanks.

[275508995]

I get the FDS_ERR_NO_SPACE_IN_FLASH error when trying to write to flash, then call fds_gc() ，the FDS callback return FDS_SUCCESS ，but when i write to flash again,still FDS_ERR_NO_SPACE_IN_FLASH ,why?

[emdi]

Probably becase you don't have space in flash.

[275508995]

thank you,emdi how to check no space in flash? do you have a Good method？ i think i have enough space

[emdi]

Well, that error tells you that there is no space in flash. You can obtain some information by reading the output of fds_stat() although it doesn't directly tell you how much space is available, you'd have to do some math. If you want to store more data in flash, delete an old record, run garbage collection and try again.

[emdi]

Then you could try to run fds_stat() and check the field 'largest_contig': it contains the size (in words) of largest record that you can write to flash at that moment.

If you want to store let's say 128 bytes, first convert that to words: 128/4 = 32. Then check that the resulting value is smaller than 'largest_contig'. If it is, you can fit the data in flash, otherwise you will receive FDS_ERR_NO_SPACE_IN_FLASH. In that case, delete something, run garbage collection and retry.

[275508995]

emdi: fds_stat show log below open_records=2 valid_records=38 dirty_records=16 words_reserved=0 words_used=1021 largest_contig=1024 freeable_words=493

it looks have space ,but log show flash is full,why?