Post by thread:17C756

At 02:55 PM 6/3/97 +0000, you wrote: >Can the PICstart Plus program the 17C756. If not what programmer can ? > >TIA, >A. Almeida > Previously I replied: According to the information I have the PICSTART PLUS and promate both can program the 17C756 with an adapter. I don't know anything more than this. I think you will have to approach microchip for details yourself. As for 3rd party programmers, microchip have not released the programming specs yet so I don't see how any 3rd parties can be supporting it. I have just started pushing for these details myself. I think we have waited long enough. Jim Now I have further information courtesy of microchip and I am offering support for the 17C752 and 756 with my low cost warp-17 programmer. The wiring diagrams for all 17C75x package types is in the adapter file on my web page. http://www.labyrinth.net.au/~newfound/adapter.html The driver will be placed there shortly but will require the warp-17 "TM4" firmware release for full 17C75x support. Jim

I am starting a project using a PIC17c756 and need to know if any one has used them before. The book I have tells me that "The boot code is normally programmed into the PIC17cXXX using a PRO Mate or PICStart Plus or any third party programmer." Does this mean that the boot code is not in a new 17c756? I have the PICStart Plus but no adapter to use it with the 17cXXX. Once the boot code is in I can use a COM port on my PC to send the program to it. The boot code will not erase from the PIC so I only need to get the boot code into the PIC is that right? If I use a COM port on my PC, what software can I use to send the code to the PIC? I does not tell me what baud rate to use or how to deal with configuration bits or reply's from the PIC. Any help would be great thanks. Roy Souther spam_OUTsilicontao_royTakeThisOuTtechnologist.com

Hi Roy: Re: {Quote hidden}>I am starting a project using a PIC17c756 and need to know if any one has >used them before. >The book I have tells me that "The boot code is normally programmed into the >PIC17cXXX using a PRO Mate or PICStart Plus or any third party programmer." >Does this mean that the boot code is not in a new 17c756? I have the >PICStart Plus but no adapter to use it with the 17cXXX. Once the boot code >is in I can use a COM port on my PC to send the program to it. The boot code >will not erase from the PIC so I only need to get the boot code into the PIC >is that right? If I use a COM port on my PC, what software can I use to send >the code to the PIC? I does not tell me what baud rate to use or how to deal >with configuration bits or reply's from the PIC. >Any help would be great thanks. I think you're referring to uChip's TB015 that deals with programming a PIC17C756 via boot code. TB015 is _an_example_ of how one might go about doing this -- i.e. the parts are pre-programmed _by_the_user_ with a "boot loader" which talks RS-232 over one of the COM ports. Then, they're stuffed onto boards, then (i.e. "in production") the boards are powered up and the final code is downloaded into them via a terminal-like program. You as the user have to supply all the code in the PIC, and program the boot loader, too. You also have to design the protocol to talk between the PIC and the terminal program or whatever you use to download code into the PIC. uChip is trying to illustrate how to avoid having to use one of their programmers in production -- instead, to follow TB105 you have the parts _preprogrammed_ with a boot loader, and then if you can supply the board with Vpp you can program (once) the on-board PROM (OTP) with your application. You would _never_ be able to erase anything in this scheme (unless it was a windowed part, in which case you could only erase it in toto), only overwrite it to NOP instructions. You would select the microcontroller mode in this example. So the short answer is that there's no code "already in" the 17C756 to implement this boot loader, software-download scheme -- it's entirely up to you to implement the whole thing. Now, one way you _could_ do it would be to use external flash memory, and configure the chip to run in exteded microcontroller mode. Without going into too much detail, this means that you dedicate the first 1/4 of the code space to what is essentially a permanent, unalterable boot loader containing also the startup and interrupt vectors, and the remaining 3/4 of the code lives in external flash memory. See p. 42 & 43 of the 17C756 databook. Your boot loader would need to be able to "talk" some common file-transfer protocol so that any terminal program can be used. It would need to understand how to re-write the flash memory with a new file sent from the terminal program. Said file would be in Intel Hex format (or Motorola S-records or whatever), so as to give the boot loader an idea of where to put the file being downloaded. The downside to this approach is that you can't dedicate less than 16k words (remember, the address space is 64k words) to the boot loader because that's where the "internal/external split" is hardcoded into the extended microcontroller configuration. I would guess that you can probably do the boot loader in less than 4k words. Hope this helps. ___________________________________________ | Andrew E. Kalman, Ph.D. .....aekKILLspam@spam@netcom.com | | standard disclaimers apply | |___________________________________________|

Roy Souther wrote: > > I am starting a project using a PIC17c756 and need to know if any one has > used them before. Me! :) See my PICextern Products! Now, i finished for the 80C251 too! > The book I have tells me that "The boot code is normally programmed into the > PIC17cXXX using a PRO Mate or PICStart Plus or any third party programmer." > Does this mean that the boot code is not in a new 17c756? I have the > PICStart Plus but no adapter to use it with the 17cXXX. Once the boot code You can obtain the Adapter on DIGIKEY! I got it there! > is in I can use a COM port on my PC to send the program to it. The boot code > will not erase from the PIC so I only need to get the boot code into the PIC > is that right? I did a Boot LOADER! > If I use a COM port on my PC, what software can I use to send > the code to the PIC? I does not tell me what baud rate to use or how to deal > with configuration bits or reply's from the PIC. I can send the PIC17C756 on MICROPROCESSOR MODE... > Any help would be great thanks. > > Roy Souther > silicontao_royKILLspamtechnologist.com Please, See http://www.furb.rct-sc.br/~mw/isd_i.html or http://www.inf.ufsc.br/~mw/isd_i.html Miguel