I agree with Bob on the majority check. In one of my applications I could not be sure whether or not the power would stay on during the eeprom writes but I still needed to update and remember some more or less important stuff. Please have a look, and see if you can use it: http://www.piclist.com/Techref/member/AT-planet-T9/safeeeprom.htm -Andries -----Oorspronkelijk bericht----- Van: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] Namens Denny Esterline Verzonden: Monday, February 21, 2011 21:13 Aan: Microcontroller discussion list - Public. Onderwerp: Re: [PIC] Reliability of EEPROM content of 12F519 On Mon, Feb 21, 2011 at 12:14 PM, Bob Axtell wrote: >> Bob Axtell cotse.net> writes: >>> I spend several weeks on this, finally pinning the problem on our >>> Blessed >>> Microchip (sigh). >> ... snip >>> This method, that I call "Best of 5", always works for me. >>> >>> Otherwise, drop the internal PIC EEPROM and use an external EEPROM, >>> which >>> does not have super small cells. >> >> Bob, thanks for sharing that. This is majority voting essentially, no?. >> Have you considered using 2 of 3 voting instead? > > Actually I have used Best of 3 (best 2 out of 3). I've used it in cases > where I would run out of EEPROM space otherwise. > > --- Bob A > I can definitely vouch for Bob's best of 5 method. I'll also add a link here: http://www.cs.utexas.edu/~moore/best-ideas/mjrty/index.html The Moore/Boyer majority vote algorithm. It's a fairly ingenious and easy to implement - do read it throughly though, there's a couple pitfalls and I've seen several (supposedly competent) people completely misunderstand it. -Denny --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .