SV: Re: SV: [sdiy] DROID3, Another AVR Synth?

[karl dalen]

--- Rainer Buchty <rainer at buchty.net> skrev:

> >Well, it depends, the flash memory of AVR's are stated to retain its
> >contents for 10 years (at specified temp range) and probably longer at
> >25deg C but what happends then???
> 
> Assuming that the manufacturer provides OS-dumps -- which is definitely
> true for DIY stuff 

Yes!

-- just re-flash the thing.

Its not that easy, when flash memories starts to detoriate
they lose segments and individual bits, re- flash dont help
because 99% of the embedded MCU meories does not contain
a faulty bits information as NAND flash does. So when a new
write is done to the faulty bit location nothing tells
the programmer if the bit location will/or not hold its
written data.

Obviously cou could implement a routine that does
fault checking and correction in the the MCU you
are using but still, when the bit it gone its gone!

I have had this problem with one
of my early flash based synths! (ESQ1)

However im still intressted to hear what folks
have to say regarding the 10 years of data 
retendention!

(flame shields up, just in case)

KD