Have big problems with hc12 evaluation boards, please help

[Evgenij]

Hi, I've got big problems with HC12 evaluation boards (m68evb912b32). Nearly half year ago 4 hc12 evaluation boards was given to me to make some work, that must be ended, but now I've got problems:

1) Some time ago in moment I was programming MCU flash the electricity failed down and HC12EVB stop worked, e.g. when I connect to EVB by COM port I have no ansver from boot loader, that was preinstalled in MCU flash by manufacturer. And no programm can be write to flash.

2) So, I decided to end project only with three EVBs. But today I lost 2nd EVB! In moment I connected to EVB to program flash I've got a message some as "Target can't connect to MCU. Please, restart your target...". Some of this. All times after this any reset of MCU or boot programm have no result. There is no ansver from this MCU also!!

Lost two EVBs is very-very bad for me. Please help. What can I check, what to do to get ansver if my MCUs realy die. All time I worked with EVBs I've got not very frequent problems with flashing (not stabile flashing - not every MCU flash programming attempt get success), also I have no debuger, so I write my programm to MCU flash each time I may to debug or check program.

Please help, I hope for your ansvers.

[pgo]

Dear Evgenij,

It would seem likely that the EEprom on the non-working boards has been corrupted in some way due to failures during programming using DBug12.  I can suggest some things to check or try.

Firstly, the manual for the  m68evb912b32 suggests that it may be used as a BDM interface for another board.  It should be possible to use one of your working boards to re-program the non-working boards.  It's a long while since I played with DBug12 but I think it supported an option to program other board with a Srecord file.  This might be worth investigating.  The required file to program is available on this page (I believe!)

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=68HC912B32&fpsp=1&tab=Design_Tools_Ta...

Debugging using DBug12 is pretty painful.  I would really recommend you get or build a BDM interface.  See if TBDML discussion board if you want to see what is involved in DIY for this.

bye