Ling, I'm with you - and I do have enough memory going round to be able to
afford writing more copied (I'll never be able to wear out all the cells in
the chip, even if I wrote 100 copies of the variable of interest).

Cheers, thanks for your reply
  Roland


----- Original Message -----
From: V sml <decoder@BIGFOOT.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Wednesday, January 26, 2000 10:22 AM
Subject: Re: EEPROM endurance/error correction (long)


> What I meant for "multiple (N) copies on the same chip" is the number
> of write increases by N times to the chip/cell.  Asssuming an even
> distribution, you are reducing the lifetime of the chip/cell by N
> times.  If your total write times to the cell is X (without
> duplication), then it is the computation of:  X, 100K and 100K/N
>
> If your X is < 100K and more than 100K/N, then implementing N copies
> would need more consideration.  Are you pushing the chip to failure
> unnecessarily?
>
> If X is > 100K then EEPROM failure would be N times too often, compare
> to no duplication.
>
> If X << 100K/N then .. no issue.
>
> BTW, mind sending me your code when done?
>
> Dwaine Reed, I'm still interested in your code.
>
> Cheers,  Ling SM
>
> >Ling, your idea of storing the data on different chip is also a good
> one.  In my case I will have more than one chip, so it will be used.
> Multiple copies in the same chip, however, will NOT hasten the failure
> of the chip, if AN537 is to be believed, since the EEPROM deteriorates
> on a cell by cell basis.
>