RE: FDS size for particular amount of data:

ChinmayDixit97 — Mon, 13 Feb 2023 17:13:59 GMT

Hey Jorgen,

Thanks for the detailed and prompt reply. I will make the changes according to your suggestion.

Thanks a lot. Closing this ticket.

Chinmay.

RE: FDS size for particular amount of data:

Jørgen Holmefjord — Mon, 13 Feb 2023 09:24:27 GMT

Hi,

The virtual page size is in number of words (32-bits). With 3 virtual pages of 2048 words, you can store up to 2*(FDS_VIRTUAL_PAGE_SIZE-PAGE_TAG) words = 2*(2048-2) words = 4088 words = 16352 bytes.

Note that each record requires a Record header, which takes up 3 words (12 bytes). This means that each of your records will take 212 bytes, and you can store up to 77 of these records. Note that a record cannot be split between two virtual pages, so you are limited to 38 records of this size on each virtual page. If your data is not static, but you intend to update it occasionally, it is good to have room for more records than you are planning to store. When you update a record in FDS, it will write a new record and invalidate the old one until you run garbage collection. This limits the number of flash page erase operations you need to perform. If you have space for few extra record writes/updates, you will have to perform garbage collection more often in order to free space for new writes, which will wear down flash faster.

Best regards,
Jørgen