On 4/27/05, Olin Lathrop <olin_piclist@embedinc.com> wrote:
> Marcel Duchamp wrote:
> > Looking at the datasheet (39663A.pdf) for the PIC18F87J10 Family, there
> > is a table:
> >
> > Characteristic              PIC18F87J10 Family      PIC18F8722 Family
> > Program Memory Retention    10 years (minimum)      40 years (minimum)
> 
> This is what I was trying to point out, but wasn't sure what Microchip had
> released about it yet.  This is a major difference from previous parts, and
> I think 10 year lifetime is a serious limitation.  That would have been
> unsuitable for the vast majority of my projects.

Is this really even the case or is it simply that the datasheet is
preliminary and they do not know the answer yet?  A lot of the stuff
in there is marked TBD.  I would expect that they will find through
their accelerated life tests that the flash retention is in-line with
other parts.  Does anyone (does Microchip?) really make an flash with
only 10 year retention?  We hear stories on the list about people
using "10 year" EEPROMs for 25 years now.

> > I've seen the "J" in the partnumber in the recent past but do not know
> > what the meaning of it is.
> 
> I believe that indicates a particular fab process (1/4 micron?).  These
> chips all seem to have the characteristic of low flash retention and that
> they only run at 3.3V.

Is this an issue with the process or is it just a new process to
Microchip and they don't want to make claims that don't stand the test
of time?

Bradley

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