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Subject: Re: UBI/UBIFS: dealing with MLC's paired pages
To: dedekind1@gmail.com, Richard Weinberger <richard@nod.at>,
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From: Andrea Scian <rnd4@dave-tech.it>
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Date: Fri, 18 Sep 2015 11:38:23 +0200
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Boris, Artem,

thanks to both of you for you detailed description.
I'll follow this development, for sure I'll learn a lot :-)

Kind Regards,

-- 

Andrea SCIAN

DAVE Embedded Systems

Il 18/09/2015 09:54, Artem Bityutskiy ha scritto:
> Hi Andrea,
>
> On Fri, 2015-09-18 at 09:17 +0200, Andrea Scian wrote:
>> I perfectly understand the reason why using nandsim (and powercut
>> simulator in general) but, AFAIK, the powercut problem is hard to
>> "simulate" because the main issue is when the device see a loss of
>> power
>> in the middle of an operation (page write or block erase)
>
> This is right, and no doubts real power cuts testing is the most
> important thing.
>
> However, at the beginning, it is very hard to develop if you do not
> have a quick way to verify your ideas. Simulation is exactly for this -
> to make the first reliable draft. Once that work, you go to the second
> stage - real HW testing.
>
> Real HW testing requires a real power cycle, no guarantees power cut
> happens at the right moment, so you may spend hours emulating just one
> paired-page case. Compare this to just running a script, and it
> emulates you 100 paired-page cases during 10 minutes. And you can
> emulate it easily at the interesting places, not just during the main
> data writes.
>
> So, to recap, I suggest emulation to make the first draft, and then
> start heavy real testing to shape the final solution.
>
> Artem.
>