Flash EPCS access problem

Hi Jérôme,

> I can't write a block entirely (65536 bytes, I don't have enough memory to store such amount of

> datas), so I would like to write only part of a block,

You can write as little as you like -- but no more than the page size.

> The problem is that each access with 'alt_write_flash' function seems to erase the entire

> block/sector of the flash

Correct. You can either erase a single sector, or the entire device. There's no way to erase

anything smaller than a sector.

> Is there a solution to my problem ?

If you need to preserve some data in the sector, you need to: read--modify--erase sector--write sector.

If you don't have enough memory (RAM) to read an entire sector, you'll need to be creative.

You could try reserving a sector to hold a copy of the original sector while you perform the update.

It's very not pretty -- but it can work.

Regards,

--Scott