BTW: What does it mean "infrequent"? You can overwrite flash about 1k times,
but it's not guaranteed. You can store calibration data for example that you
made only once or twice and you can make the FW update couple of times but I
would not rely on it.

Anyway, if you need permanent storage other than the internal eeprom why do
not you use some external ones with spi or i2c?

Tamas


On Dec 13, 2007 1:30 PM, Xiaofan Chen <xiaofanc@gmail.com> wrote:

> On Dec 13, 2007 8:38 PM, Matthew Rhys-Roberts <matt@nu-ins.com> wrote:
> > Will someone correct me if I'm wrong about this?
> >
> > As far as I can tell, writing (i.e. erase-writing) to any PIC EEPROM
> > address will disrupt the stored charge in neighboring memory cells.
> > Eventually, if written enough times, EEPROM data corruption may result.
> > Microchip recommend using an EEPROM refresh routine periodically, in
> > cases where erase-write cycles are likely to approach 1- to 10-million
> > times ("specification D124").
>
> Which PIC are you using? Have you checked the errata?
>
> > I'm only asking so I can make a sensible choice between EEPROM and Flash
> > program memory, for storing some infrequently changed non-volatile
> > constants.
>
> I can not relate this paragraph with the previous paragraph.
> Since it is infrequent, you can use either EEPROM or Flash
> but I think EEPROM is easier if your PIC has the EEPROM.
>
> Anyway, you need to tell us which PIC you are going to use first.
>
> Xiaofan
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist