Using a custom HCS12 board

Technical Note 51007






12/14/2015 2:12 PM


To load and debug code into a self-designed HCS12 board with IAR Embedded Workbench for HCS12, follow the steps below. Note that this Technical Note does NOT apply to evaluation boards sold by Freescale, SofTec etc!

Prepare the board

  • Setup the board to startup in "special single chip" mode when powered on. This can be done by pulling pins BKGD, MODA and MODB low during reset.
  • Add a connector (for the BDM interface) to the board with BGND, GND, RESET and VDD connected.
  • For all other details (such as voltage levels on Vdd and VPP), study the documentation from Freescale and make changes to the board if needed.

Actions to take in IAR Embedded Workbench for HCS12

  • Note: Downloading to external memory (flash or EEPROM) which needs special writing algorithm is not supported.
  • Select the proper chip derivative.
  • If needed, edit the corresponding .ddf and .xcl files to suit the board configuration.


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