Post by thread:[PIC]: Code Protected p16f84

part 1 422 bytes content-type:Text/Plain; (decoded quoted-printable) Is there any way to unprotect a p16f84? I was using warp13 programmer and inadvertently wrote the code word with cp on. This is a newbie question and haven't found any answers yet. Your time is appreciated greatly. Mark -- 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 part 2 531 bytes content-type:image/gif; (decode) part 3 2 bytes -

You'll need to erase the chip, but therefore can't read the code back from the chip. Just reprogram it again. Cheers, -Neil. On Saturday 03 May 2003 14:18, Mark, WT6P scribbled: > Is there any way to unprotect a p16f84? I was using warp13 programmer and > inadvertently wrote the code word with cp on. > > This is a newbie question and haven't found any answers yet. > > Your time is appreciated greatly. > > Mark -- 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 12:18 PM 5/3/2003 -0700, Mark, WT6P wrote: >Is there any way to unprotect a p16f84? I was using warp13 programmer and >inadvertently wrote the code word with cp on. I don't think so. This is a major difference between the PIC and AVR procs. A locked AVR can still be erased, and erasing clears the lock bits. So you can't lock yourself out, at least not that way. -- 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

part 1 1233 bytes content-type:Text/Plain; (decoded quoted-printable) Well, thank you for the brain jogger...I needed to set the config word for all bits on and then rewrite the config word. That was just what was needed I erased it and reset the config word WITHOUT copy protection. Thanks, Mark --{Original Message removed} part 2 531 bytes content-type:image/gif; (decode) part 3 2 bytes -

At 02:40 PM 5/3/2003 -0500, Picdude wrote: >You'll need to erase the chip, but therefore can't read the code back from >the >chip. Just reprogram it again. Interesting, I thought the code protect was a one-time thing on PICs. Has that changed? -- 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

Mark, check your mail settings. Your whole mail appears as two attachements (at least for me). Use "plain text". And take that horrible IMSTP.GIF away ! It adds nothing to your posts... Best Regards Jan-Erik Soderholm. > -----Original Message----- > From: Mark, WT6P [spam_OUTwt6pTakeThisOuTATTBI.COM] > Sent: den 3 maj 2003 21:58 > To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU > Subject: Re: [PIC]: Code Protected p16f84 > > << File: ATT136152.txt >> << File: IMSTP.gif >> -- 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

You can not *read* the code. But you can *erase* it (as when re-programming). I don't know it this ever changed... Jan-Erik. Dave VanHorn wrote: >Interesting, I thought the code protect was a one-time thing on PICs. >Has that changed? -- 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

Correction! You are right, of course, on the PIC's that are unerasable... Jan-Erik. -----Original Message----- From: Jan-erik Soderholm (QAC) Sent: den 3 maj 2003 22:06 To: PICLISTKILLspamMITVMA.MIT.EDU Subject: Re: [PIC]: Code Protected p16f84 You can not *read* the code. But you can *erase* it (as when re-programming). I don't know it this ever changed... Jan-Erik. Dave VanHorn wrote: >Interesting, I thought the code protect was a one-time thing on PICs. >Has that changed? -- 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 -- 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 12:18 PM 5/3/2003 -0700, Mark, WT6P wrote: > >Is there any way to unprotect a p16f84? I was using warp13 > programmer and > >inadvertently wrote the code word with cp on. > > I don't think so. > > This is a major difference between the PIC and AVR procs. > A locked AVR can still be erased, and erasing clears the lock bits. > So you can't lock yourself out, at least not that way. MCHIP flash parts CAN be unlocked, just issue a "bulk erase" command, you will then be able to unset the code protect. With most programmers clicking "erase all" does exactly this. TTYL -- 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 02:40 PM 5/3/2003 -0500, Picdude wrote: > >You'll need to erase the chip, but therefore can't read the code > back from > >the > >chip. Just reprogram it again. > > Interesting, I thought the code protect was a one-time thing on PICs. > Has that changed? With EEPROM/OTP parts yes (although some WILL reset if exposed long enough), with flash parts no. TTYL -- 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

> You can not *read* the code. > But you can *erase* it (as when re-programming). > > I don't know it this ever changed... With parts that are EPROM/OTP, once you set CP that's it, no way to "unset" it (actually physically it's the other way around I think but lets ignore that for now...). Some parts WILL unset if left in UV long enough, unfortunately some discovered that if they focused a UV laser right on that part of the chip it would be possible to disable code protection but leave the rest of the code intact. MCHIP now puts a "sheild" above where this bit is to prevent that. TTYL -- 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

"Mark, WT6P" wrote: > > Is there any way to unprotect a p16f84? I was using warp13 programmer and > inadvertently wrote the code word with cp on. > I don't know about all you other fellers, but I code protect 16F84's, 16F876's and 16F877's often, and almost as often, re-program them. (I suffer from stupidity, ya see, and I have to do things lots of times before I get it near right!) A code protected chip will read back zeros in the page or pages that are protected by the configuation, so you can't read the code on those pages. Then, an "erase before programming" just erases the lot, and programs, and protects again, if so configured. A trick I do use, is not to use page 0 for too much, (hafta use 000 and 004 of course) and I write a few lines of data (DT) which tells me what is on the chip, and I don't protect page0. So, I can still read page0, which tells me what's on it. I can't wait for one of you blokes to come on and describe about a million reasons why I can't, or shouldn't do this! Regards to all. Howard Simpson. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads