Post by thread:[PIC]: developing with 18J chips?

Anyone here with experience in 18J (= Limited Times Programmable) chips? IIRC the previous bunch claimed to be 1k times programmable, the new chips with ethernet only 100 times! For a developer that is almost OTP... And SMD packages only, so after N (100 or 1k) programming cycles you'll have to ditch your PCB. How do you develop with those chips? Small PCB with only the chip, and ditch only that? How do you know you have exceeded the number of programnming cycles? (how does it show: faulty erase, faulty programming, loss of code after succesfull programming?) Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

On Sun, 4 Feb 2007 20:20:42 +0100, "Wouter van Ooijen" wrote: <snip> >For a developer that is almost OTP... And SMD packages only, so after N >(100 or 1k) programming >cycles you'll have to ditch your PCB. How do you develop with those >chips? Small PCB with only >the chip, and ditch only that? That's sure not a lot of programming cycles. For development, the approach that I think I'd take would be to use an SMD-to-DIP adapter board that could be plugged into a DIP socket on the main PCB. Rather than trashing the adapter board, I'd try removing the old chip and soldering a new one in place. That should be possible but would need to be done carefully to avoid damaging the board. Regards, Bob

On Sun, 4 Feb 2007, Wouter van Ooijen wrote: > Anyone here with experience in 18J (= Limited Times Programmable) chips? > > IIRC the previous bunch claimed to be 1k times programmable, the new > chips with ethernet only 100 times! I think that's 100 "minimum", 1K "typical". We've done a couple of projects with the 18F25J10 without any issues. They weren't huge projects (5-10KB of code space), so I might have gone over 100 cycles but not anywhere near 1,000. But I guess it's something to think about if you're developing a 100KB project on one of these. Be sure to check the clock specs on these as well. Some have minimum crystal oscillator speeds as high as 4 MHz. -- John W. Temples, III

> That's sure not a lot of programming cycles. For development, the > approach that I think I'd take would be to use an SMD-to-DIP adapter > board that could be plugged into a DIP socket on the main PCB. Just about do-able for a 64-pin chip, but I don't think its feasible for a 100-pin (or more) chip. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

> > Rather than trashing the adapter board, I'd try removing the old chip > and soldering a new one in place. That should be possible but would > need to be done carefully to avoid damaging the board. Chipquik (http://www.chipquik.com/), available from many sources including DigiKey, is fantastic for this kind of work. I've removed everything from SOIC8 to TQFP80 with no problems with just Chipquik and a little patience. -n.

On 2/4/07, Wouter van Ooijen <spam_OUTwouterTakeThisOuTvoti.nl> wrote: > > That's sure not a lot of programming cycles. For development, the > > approach that I think I'd take would be to use an SMD-to-DIP adapter > > board that could be plugged into a DIP socket on the main PCB. > > Just about do-able for a 64-pin chip, but I don't think its feasible for > a 100-pin (or more) chip. In DIP 0.1" (2.54mm) not, but in smaller pitch definitely yes. Taker a look to 486/586/P1 sockets. There are sockets available even for 529 pin BGA packages at 0.5mm pitch. Vasile

Most of the "J" series devices have a pin compatible cousin that is the normal bizzillion flash cycles (ok..not that many...but more than 1K), so put one of those parts down, develop with it and then switch to the J part when your done. --------------------------------- Get your own web address. Have a HUGE year through Yahoo! Small Business.

> Most of the "J" series devices have a pin compatible cousin > that is the normal bizzillion flash cycles (ok..not that > many...but more than 1K), so put one of those parts down, > develop with it and then switch to the J part when your done. So far I ignored these J chips, but they are the only ones that have the Ethernet integrated. Maybe 'normal flash' versions with Ethernet will appear lateron. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

True...forgot about the integrated Ethernet devices. They also have dual uarts, I2C so to make a generic controller, with plenty of I/O and methods of I/O....kinda sorta nice. Wouter van Ooijen <.....wouterKILLspam@spam@voti.nl> wrote: > Most of the "J" series devices have a pin compatible cousin > that is the normal bizzillion flash cycles (ok..not that > many...but more than 1K), so put one of those parts down, > develop with it and then switch to the J part when your done. So far I ignored these J chips, but they are the only ones that have the Ethernet integrated. Maybe 'normal flash' versions with Ethernet will appear lateron. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

> So far I ignored these J chips, but they are the only ones that have the > Ethernet integrated. Maybe 'normal flash' versions with Ethernet will > appear lateron. maybe microchips normal process is unsuitable for the ethernet controller, note that thier standalone SPI ethernet controller is also a 3.3V j series chip.

> -----Original Message----- > From: piclist-bouncesKILLspammit.edu [.....piclist-bouncesKILLspam.....mit.edu]On Behalf > Of alan smith > Sent: 05 February 2007 15:12 > To: Microcontroller discussion list - Public. > Subject: Re: [PIC]: developing with 18J chips? > > > Most of the "J" series devices have a pin compatible cousin that > is the normal bizzillion flash cycles (ok..not that many...but > more than 1K), so put one of those parts down, develop with it > and then switch to the J part when your done. Right, as well as the lack of ethernet already mentioned that means you either have to design your board to cope with running the PIC at 5V or run at a very low clock frequency.

>Most of the "J" series devices have a pin compatible cousin >that is the normal bizzillion flash cycles (ok..not that >many...but more than 1K), so put one of those parts down, >develop with it and then switch to the J part when your done. Yep, I'd do the same... -- Ciao, Dario

> > So far I ignored these J chips, but they are the only ones > that have the > > Ethernet integrated. Maybe 'normal flash' versions with > Ethernet will > > appear lateron. > maybe microchips normal process is unsuitable for the > ethernet controller, note that thier standalone SPI ethernet > controller is also a 3.3V j series chip. I will wait and see. The ENC has no flash, so I don't know whether its process is tied to the 100-cycles-only flash. I have much less problems with the 3.3V (but 5V tolerant inputs *and outputs* would be nice). Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

Wouter van Ooijen wrote: >> That's sure not a lot of programming cycles. For development, the >> approach that I think I'd take would be to use an SMD-to-DIP adapter >> board that could be plugged into a DIP socket on the main PCB. > > Just about do-able for a 64-pin chip, but I don't think its feasible for > a 100-pin (or more) chip. I thought that with a hot air station, desoldering and resoldering even the bigger TQFP cases is a pretty standard procedure. And you shouldn't have to do it every week :) Gerhard

> I thought that with a hot air station, desoldering and > resoldering even the > bigger TQFP cases is a pretty standard procedure. And you > shouldn't have to do it every week :) For me personally that would probably be an adequate solutiuon. But on a heavy debugging day I can easily imagine doing > 100 programming cycles. But I was many wondering how I could make a DwarfBoard product for these PICs, for customers that probably don't have a hot-air station. I guess not. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

Wouter van Ooijen wrote: >> I thought that with a hot air station, desoldering and resoldering even >> the bigger TQFP cases is a pretty standard procedure. And you shouldn't >> have to do it every week :) > > For me personally that would probably be an adequate solutiuon. But on a > heavy debugging day I can easily imagine doing > 100 programming cycles. When I reprogram during debugging, it's like asking questions to the project. Between making the code changes to ask the right questions, programming the new code, running enough tests to get all the "answers" from the unit, checking out the sources, datasheets etc. to put the answers into perspective and come up with new questions (to ask to the project) where the answers were not yet conclusive, it usually takes me more than half an hour between programming cycles, even during heavy debugging traffic. > But I was many wondering how I could make a DwarfBoard product for these > PICs, for customers that probably don't have a hot-air station. I guess > not. Here we have many small cell phone repair shops that have hot air stations and do such work for quite reasonable fees. Gerhard

> When I reprogram during debugging, it's like asking questions to the > (snip) > it usually takes me more than half an hour between programming > cycles, even during heavy debugging traffic. OK, interesting, but I don't see how that is relevant to me. I sometimes use that mode, with hours of reading and thinking between tries, sometimes I use many 'fast' tries. In both cases I have good reasons to do it that way. > Here we have many small cell phone repair shops that have hot > air stations and do such work for quite reasonable fees. Hmmm. I would not trust the average phone shop sales man here to hold a screwdriver at the correct end on the first try. Phone *repair* shops must be hidden very well, I never saw one. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: http://www.voti.nl/hvu

Wouter van Ooijen wrote: >> it usually takes me more than half an hour between programming cycles, >> even during heavy debugging traffic. > > OK, interesting, but I don't see how that is relevant to me. It's probably about as relevant to you as your >100 cycles per day are to me :) >> Here we have many small cell phone repair shops that have hot air >> stations and do such work for quite reasonable fees. > > Hmmm. I would not trust the average phone shop sales man here to hold a > screwdriver at the correct end on the first try. Phone *repair* shops > must be hidden very well, I never saw one. Yes, I almost thought that might be so. Gerhard