Error in programming...

[mke_et]

I have a project that is Star12 based, and for the most part, it going great. I'm using a USB BDM Multilink pod to program the boards, and for a couple of hunder units, I've had only two problems.

I've had two units that fail with "Error while loading diagnostics to target system. The chip may be secured, or the derivative selected may be wrong"

One board was dead as built, and never made to work. The other board was one of my 'test' boards that I program and give to the shop to make sure I didn't put in any new bugs. It's worked for a long time and suddenly decided to go flakey. (That board also, once this started, sometimes gives an error that it fails to establish a communication speed.)

Now, the one board going bad I just placed aside, but this one was built up and up until failure worked fine. In fact, after it failed, I got it to reboot and it still had the OLD software loaded. Indicating it never got to erase.

Any ideas? Or is this just the cost of production?

Mike

[mke_et]

Well, I may have found the problem. At least for one of the boards. Seems it had pullups because it was attached to an external test setup. While these weren't attached to any pins directly on the processor, there IS the possibility that they could 'loop' through the unregulated 12v feed (which comes in from the test setup if it is connected instead of the normal power in) and that may have caused a noise issue.

Also, since the BDM connector is 'hidden' when the unit is assebled, this particular unit has a 'pigtail' out to a BDM connector hanging free in space, about 8 inches long. The combination of the two factors I suspect were the problem.

At this point, I'm not even sure it deserves further attention or investigation.

Mike

[Alban]

Hi Mike,

Well the manufacturer of the tool will tell you this tool is not designed for production.
What probably happened is you had a problem during the init with a signal having some noise or something of the same spirit. As the erasing sequence was not performed properly, the MCU could not be re-programmed.

I often have trouble with this tool. The MCU seems just dead. I go for a coffee, come back and it works fine... Maybe something floating in my EVB which keep a level thanks to PCB capacitance.

Moral of the story: go and take a coffee... Or as a computer user: "HAve you tried to switch it off and on again ?" (British will understand)

Cheers,
Alban.