[A83] Re: What is the problem with flash writes (in general)


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[A83] Re: What is the problem with flash writes (in general)




> Even so, 1,000,000 is a lot of erases, I don't think we have
> too much to worry about there.
> 
> -Dan Englender

Suppose 10 flash erases a day:

1'000'000/(10*365) = +/- 275 years of flash memory.
I think by then the calc would be dead of other problems :-)

(still, It's a nice way to preserve data for future generations ;-)
--(Peter-Martijn)


> 
> 
> ----- Original Message -----
> From: "Kirk Meyer" <kirk.meyer@colorado.edu>
> To: <assembly-83@lists.ticalc.org>
> Sent: Monday, July 09, 2001 1:01 PM
> Subject: [A83] Re: What is the problem with flash writes (in general)
> 
> 
> >
> > Interesting -- is this right: to garbage collect, the OS must usually
> erase
> > a ~64K chunk. This would mean this chunk has to be backed up to somewhere
> > else in FLASH. After it has been erased, it would be copied back. It would
> > seem like the swap area where things are swapped to (unless it is not
> > constant) would set the minimum FLASH life -- since it would be getting
> > written to by far the most. I assume that this is the meaning of the
> > sections of FLASH designated "SWAP/USER" in the SDK guide.
> >
> > I hope the calc isn't always actually garbage collecting when it says
> so --
> > for example, when overwriting an APP that exists, it garbage collects?
> Seems
> > wasteful. But if the life is really 1,000,000 cycles, that's probably
> longer
> > than the other equipment will last.
> >
> > -----Original Message-----
> > From: assembly-83-bounce@lists.ticalc.org
> > [mailto:assembly-83-bounce@lists.ticalc.org]On Behalf Of Dan Englender
> > Sent: Monday, July 09, 2001 10:46 AM
> > To: assembly-83@lists.ticalc.org
> > Subject: [A83] Re: What is the problem with flash writes (in general)
> >
> >
> >
> > The way the Flash chip works, you have to erase either the whole chip, or
> > whole sectors (sectors vary in size between 8K (only two of these) and 64K
> > (most are this size)).  This is what wears the flash (and what causes your
> > screen to dim...noticeable especially on HW1 TI-92's and TI-89's ... but
> > also on the 83P when you're loading a new OS) and there's not much way to
> > get around it.  So, if you need to *set* any bits on the sector, you're
> > going to have to erase it.  If you wanted to set some bytes to zero, you
> > wouldn't have to erase first.  You can reset bits whenever you like, but a
> > set requires an erase.
> >
> > Hope that's clearer (erase loading 0FFh causes some mix-ups in
> terminology),
> >
> > -Dan Englender
> >
> >
> >
> 
> 
> 




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