Data sheets: PIC(AXE) or Microchip?

Discussion in 'The Projects Forum' started by Louise, Mar 3, 2010.

  1. Louise

    Thread Starter New Member

    Jan 17, 2010
    Could anyone please enlighten me regarding the difference between the information contained in the data sheets on the PICAXE web page, and that contained in the data sheets from the Microchip web page? (The latter 'turned up' when I entered the model number from the top of the chip into an Internet search engine). I understand that the PICAXE chips have a 'boot loader' added that makes it easier to interface with the chip (for programming). Does this involve a trade-off that results in reduced functionality? I'm interested in finding out more information about I/O ports and flags (etc) than that contained in the PICAXE data sheets.
    Any help would be gratefully received.
    Many thanks - in anticip . . . ation!
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    I'd go to the PICAXE Forum for those questions. Lots of very experienced and helpful people there. (Not that there aren't here. ;) )

  3. Louise

    Thread Starter New Member

    Jan 17, 2010
    Good idea! I'll try that. Many thanks!
  4. Art

    Distinguished Member

    Sep 10, 2007
    I think it would have to, but I'm not certain exactly how the Picaxe works.

    The main difference is the Microchip datasheet is the official manufacturer's
    specs and data.
    The picaxe is a proprietary product based on the pic chip.
    Another example that I better understand is the Basic Stamp (similar product to Picaxe)

    The basic stamp contains a live basic interpreter.
    The program you write is interpreted by the chip at runtime by code that already exists on the chip.
    You can't take that program you wrote for the Basic Stamp (or Picaxe),
    and run it on a pic chip that does not contain that pre-written proprietary interpreter code.

    This live interpretation slows down the chip considerably.

    If you program for a pic chip in Microchip assembler (or even with a third party compiler like PicBasic Pro),
    Your program is compiled to Microchip RISC Assembler before it leaves your PC.
    The pic is essentialy running it's native language, and does so as fast as it
    was designed to.
    A third party compiler may not produce an assembler counterpart that is efficient as a program written directly in RISC Assembler,
    but the program does not have to be interpreted live, and you don't need to begin with a pic chip that contains some
    company's proprietary code on it.

    Cheers, Art.