Board is not debugging

[Sanju12345]

Hi,All. I have a problem to debug my board use Codewarrior.My developer kit is "S12XFSTARTERKITE"(S12XF 2-node Starter Kit),Codewarrior version is V5.1. Yesterday,I was debugging my 2-nodes FlexRay program.However,during Debugging,A problem appeared, I can't download my programme into one EVB9S12XF512E. The I try to download programme into another EVB9S12XF512E,the same situation happen again. Now the 2 EVB9S12XF512E still work as the last time download programme ,Only problem is that I can't download any programme into my board. And I doubt that the MCU has been Secured. In the process of Degugger,A "HI-WAVE" window popping firstly,said "Communication with the target failed:The target MCU has no clock or wrong BDM clock speed is used or derivative is secured",press "confirm" button,then appear a "Warning" window,said "Loading a new application will stop the execution of the current one",press "OK".Very soon,a "Non Volatile Memory Control" window appear,said "Error while loading diagnostics algorithm to target system,The chip may be secured,or the derivative selected may be wrong".after "confirm".A "NVM Programmation" window appear which says "This opeartion has been canceled". That's all the process I met. I also use the "P&E Microcomputer System MC9S12 Unsecure Program" to unsecure the MCU,But It still can't work,said that "ERROR - Communication with target,Appropriate interface speed not found". Now,I don't know what to do and how to do,could anyone give me some good suggestion?Thank you very much,I will waiting for the on-line.

[pgo]

Dear Sanju,

I may be asking the obvious but have you done the following (as described in the manual):

Jumper J27 must be disconnected before programming. After programming,
reconnect J27 to enable the reset line for the SBC.

bye

[Emac]

You might try holding down the reset button as you first start the programmer. I am theorizing that a program might be executing while you are trying to run.

[Lundin]

The S12 family is using a programming interface called BDM (background debug mode). The BDM programming pod pulls the reset pin low before trying to access the CPU.

[Emac]

Roger that Lundin, I have seen some systems that have a power supply watchdog or other interface to the reset line that (whatever) BDM programmer interface the developer is using doesn't have enough pull to override the current state.  In any case, our poster has probably had his answer solved already.