Post by thread:[PIC]: Odd Programming Behavior: PICSTART Plus & P

When programming the PIC18LF452 with MPLAB 5.62 and PICSTART Plus firmware revision 3.0, I occasionally experience a strange error. Regardless of code protect configuration, it automatically programs most code protect bits as 0. All CP & table read protect bits are cleared, and table write 200-7fff is also cleared (protected). Then, when verifying the program write, the error is detected, and it displays the code protect discrepancy. I am now left with a code protected chip. Attempts to erase the chip fail. No error message is displayed, but the bits are not reset. Thus, the chip seems to be rendered unusable. This error seems to occur sporadically; it occurred on two of the five chips I tested. It has never occurred on the 50+ F442s that have been through this programmer in the past month, nor on any other chip I've programmed here. (I think that would rule out communication errors, although I don't feel like stripping the cable and testing each line) :) It may be a die problem (these *were* early adopter samples); it may be an ESD problem; it may be an operator stupidity problem. At this point, I have no problem throwing these two chips away. But I would really like to know the cause. Any ideas? Jen -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Well, I can't comment on the problem, but don't throw the chips out! I'm looking for a new keychain :) And no, I'm not kidding :P Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams "Jennifer L. Gatza" wrote: > At this point, I have > no problem throwing these two chips away. But I would really like to know > the cause. Any ideas? -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> It may be a die problem (these *were* early adopter samples); it may be an > ESD problem; it may be an operator stupidity problem. At this point, I have > no problem throwing these two chips away. But I would really like to know > the cause. Any ideas? Check the errata sheet (more like a book) for the early versions of the 18F452. I don't remember if this symptom was listed, but I do remember some bugs were so major that I couldn't use any pre-released chips for a particular project. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

>but don't throw the chips out! I'm >looking for a new keychain :) Give you something to look out for to recognise another PIC-Lister at a masters :)) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Maybe we could sell Jinx's dead chips as a fundraiser for piclist.com? You do have enough, don't you Jinx? :) Josh -- A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. -Douglas Adams "Alan B. Pearce" wrote: > >but don't throw the chips out! I'm > >looking for a new keychain :) > > Give you something to look out for to recognise another PIC-Lister at a > masters :)) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> Well, I can't comment on the problem, but don't throw the > chips out! I'm > looking for a new keychain :) > > And no, I'm not kidding :P You can have them! They're DIP's, though. You might have to bend all the pins over so that they don't break off and/or cause damage. :) I also have plenty of C442's in PLCC. If you check with each person on this list, I'm sure you'll find millions of chips that have been / will be discarded... Business opportunity, perhaps? Have fun! Jen -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

I wasn't able to find the early errata sheets online. Do you by any chance have a document number? Thanks, Jen > Check the errata sheet (more like a book) for the early > versions of the > 18F452. I don't remember if this symptom was listed, but I > do remember some > bugs were so major that I couldn't use any pre-released chips for a > particular project. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> I wasn't able to find the early errata sheets online. Do you by any chance > have a document number? Now that you mention it, I didn't get it on line either. It was handed to me by a Microchip sales guy when we were considering using the 18F452. The list of bugs in the pre-release silicon was so bad that we decided to prototype with the 16F877 with reduced features until the real 18F452s were available. That was about a year ago. I just looked and couldn't find it. I'm pretty sure I tossed it in disgust a while back. You must have gotten something similar when you got your pre-release chips. Maybe your local Microchip guy still has a copy. However, I would toss all pre-release versions of the 18F452 and replace them with the real production parts now that they are finally available. There may be more gotchas lurking that you haven't bumped into yet. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > > Well, I can't comment on the problem, but don't throw the > > chips out! I'm > > looking for a new keychain :) > > > > And no, I'm not kidding :P > > You can have them! They're DIP's, though. You might have to bend > all the pins over so that they don't break off and/or cause damage. > :) I also have plenty of C442's in PLCC. If you check with each > person on this list, I'm sure you'll find millions of chips that > have been / will be discarded... > > Business opportunity, perhaps? Well, I've got 12 8748s at home that I'm beginning to think about scrapping because they just don't have the program space for me to be bothering with them... They're ceramic 40-pins though. Not exactly easy to drill a hole in. I'll let ya know when I've blown a batch of PICs. (I guess that will be comming soon, what with the CUMP development and all... - --Brendan -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.8 for non-commercial use <http://www.pgp.com> iQA/AwUBPVA5LAVk8xtQuK+BEQIvoQCfTzzEah52ORrwHYax5tEu/U+X9HIAoJLW EsycEGnsR2jJfErS4H1poCkU =KTWp -----END PGP SIGNATURE----- -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

At 02:01 PM 8/6/02 -0700, you wrote: >Well, I've got 12 8748s at home that I'm beginning to think about >scrapping because they just don't have the program space for me to be >bothering with them... They're ceramic 40-pins though. Not exactly >easy to drill a hole in. Brass tubing chucked in the drill press, silly putty or equivalent to build a "dam" on the surface, suitable abrasive slurry will work. You could also try the carbide spade bits available at Home Despot etc. but I'm not sure they would work. Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" spam_OUTspeffTakeThisOuTinterlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com 9/11 United we Stand -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> >Well, I've got 12 8748s at home that I'm beginning to think about > >scrapping because they just don't have the program space for me to be > >bothering with them... They're ceramic 40-pins though. Not exactly > >easy to drill a hole in. > > Brass tubing chucked in the drill press, silly putty or equivalent to > build a "dam" on the surface, suitable abrasive slurry will work. That's a nifty idea... use sand and oil, or something similar... but how do I convince the slurry to move? The brass tubeing will likely be the part that gets abraided. > You could also try the carbide spade bits available at Home Despot > etc. but I'm not sure they would work. Also viable, but I doubt that the casing of the cerdip would hold up to the vibration and pressure. --Brendan -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics