[MLC NAND]: data pattern sensivity

[Qi Wang 王起 (qiwang)]

Hi Andrea,

On Thu, 2015-04-09 at 22:19 +0200, Andrea Scian wrote:
>Il 07/04/2015 19:45, Jeff Lauruhn (jlauruhn) ha scritto:
>> I read back through the posts and I think we are talking about 2
>separate things, random read time and randomization.
>>
>> Rand Read (tR) assumes you are doing a single read of a page (worst
>case), but most data is stored in blocks sequentially, so data output can
>be improve significantly by read by taking advantage of commands like
>READ PAGE CACHE SEQUENTIAL which copies the next sequential page from the
>NAND Flash array to the data register.
>>
>> Randomization is a relatively new feature, I'm no expert, but it's in
>general we know there are some distributions that are worse than others,
>and by randomizing the data we can avoid worst case and improve endurance.

Yes, Randomization can avoid worst case and improve endurance

>
>Definitely here I'm speaking about the latter.
>By looking inside the datasheet (hynix, micron and so on) I have I've
>found no MLC part that explicitly required such a implementation, apart
>the one pointed out by Boris.

For Micron MLC part, we already implement this function inside of our MLC,
so external randomization isn't needed at all.

Thanks

--
Qi Wang