Toby Landes

Getting Started

Discussion created by Toby Landes on Jun 2, 2010
Latest reply on Jun 3, 2010 by kef


  • I have been using the 68HC11 in most all my products since 1990.
  • I began using the Cosmic C compiler and Multi-Edit in 1998. 
  • In 2003 I incorporated the STMicorelectronics PSD854F2 for all RAM, ROM, addressing logic and some I/O.
  • This was a great space saver and I got more memory than with the discretes I had been using.
  • Programming was easy: I just used the JTAG port pins and software provided by STMicro
  • Now the PSD parts have all gone obsolete.
  • This means I must redsign my boards.
  • I want to stay with Freescale products
  • I want to stay with Cosmic
  • I want to upgrade to a more recent and more powerful uProcessor
  • I am considering the MC9S12A512 as my replacement device
    • It has plenty of program and storage flash memory onboard
    • It has plenty of I/O
    • It has enough onboard RAM for all my products except one and I can add external RAM for it.
    • An alternative might be the MC9S12XA512.  It has 32K RAM and this would be adequate.
    • You can get an idea of my product line by looking at



  1. Does the  MC9S12A512 seem reasonable for my products?
  2. Is it reasonable to assume that I can run single chip (no external RAM or ROM)?
  3. If so, how do I program it. 
    1. There does not seem to be any JTAG entrance to the chip
    2. I have seen some information about LRAE but I am concerned about:

                                          i.    Programming speed

                                         ii.    What if the LRAE flash area accidentally gets erased?

  1. Is there an alternative way to program it?
  2. Does Cosmic have any programming tools and/or software for these chips?
  3. I see that Cosmic has XGATE development tools.  What exactly is XGATE?
  4. Could a MC9S12XA512 help me because of XGATE?




Toby Landes

Valquest Systems, Inc.