[NTLK] Storage card specifications

Dan dan at dbdigitalweb.com
Thu Apr 7 23:06:02 EDT 2011

Hmm as I understood it, Flash basically was "burned" into the substrate
and this substrate wears out eventually after being cleared and
rewritten to.  Hence the information/state change does not eventually
"leak away".  Of course there are probably more types of Flash and this
is probably true of some of them (perhaps the old bubble memory type?).
 Although unless there has been damage to the Flash memory or just
wearing out, I haven't heard of Flash loosing its data.

But of course feel free to correct me if I am wrong here.


On 4/7/2011 10:07 PM, Bradley Loeding wrote:
> Flash is a kind of ROM. A modified form of EEPROM to be more correct. Bits
> are stored as trapped charge and can remain trapped for many years before
> eventually leaking away. Depending on the kind of flash, charge is added or
> removed from cells via quantum tunneling. This process is very slightly
> destructive to the cell structure, so bit flipping can only be done a finite
> number of times. This isn't so bad because failing cells can have their
> state transferred to fresh cells and re-indexed. This is the basis for
> bad-block-management, or wear-leveling.

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