Lpc2000

At 11:21 PM 6/19/05 +0000, philips_apps wrote:
>So, in an attempt to answer your question what happens after ten years?
>The probability of one bit in the whole flash memory failing increases
>day by day, and after ten years the fit rate is just a little higher
>than after 1 year and just a little lower than after 20 or even 50 or
>100 years. To the closest approach what will happen, nothing bad to the
>flash.
>
>There was an answer from Robert stating that reprogramming cycles have
>a stronger effect on the data retention than temperature,

Actually Robert I suggested the reverse.  I meant to anyway.  The 
assumption being that programming lifetime was limited by the strength of 
the oxide layer so that if you only used a small percentage of the rated 
cycles you would not have much effect on the oxide layer and therefore not 
perturb the retention time significantly.  Temperature on the other hand 
raises the thermal energy of the trapped electrons making tunneling more 
likely resulting in an increase in the leakage current and a drop in the 
retention time.  Also I would expect the tunneling probability and thus 
retention time to probably vary exponentially with temperature.

There seem to be relatively little literature covering this.  After I wrote 
my initial reply I did a quick search and the only thing I found was a 
Freescale application note that essentially provided the same thermal 
explanation, although it didn't cover programming cycles.  Does Philips 
have any public information on this?

Robert

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