Posted on June 22, 2012 at 09:09I've been suffering from the same problem. By yesterday, I had been using ST-Link-2, EWSTM8 of IAR, Win XP. From now on, I have Win 7, but it haven't changed anything.
I turned to both IAR & ST support with the problem, but meanwhile I haven't got an answer.
I have a few general ideas what could be a reason for the problems, and will try to check them on the next working week.
1. There is a problem with debugging channel when any of Low power modes is being used,i.e. if debugger tries to communicate with MCU, while the latter is in Low power mode, apparently, you should get this kind of error. For debugging period I canceled using of Active halt mode and, instead, I have been using a simple loop, simulating 100msec of Halt mode. However, in addition to the Active Halt mode, I use also Wait mode for short periods of 20-30 us, every 100msec. So, I suspect that sometimes ST-LINK fails when tries to communicate in this time. It's a bit difficult to me to replace this code with a simulation loop,but if I manage to do that, I will know for sure that this is not the reason for the problem. Do you use any of Low power modes ?
2. I frequently use Live watch with a dozen of variables inside. I'm not sure, but it seems to me as the more variables inside Live watch, the problem happens more frequently.
3. Do you have any serial resistor on SWIM pin ? If so, remove it, to decrease to a smaller value. In the Discover board, ST do not put any serial resistor on the SWIM channel. The problem with resistor is as SWIM is very high speed communication channel and any resistance disturb to it. We have 47Ohm, and next week I will try to remove it and to see if the problem exists.
If you have some findings, would you be so kind as to share them here on the forum ?
Thanks,
E.L.
