I have a device which I have flashed numerous times over this past week. I recently implemented a new debug connection (to replace my hack solder job), and was able to flash without issue.
Fast forward a few hours - I am now continually getting the "No Cortex-M SW Device Found" error. I think of 40+ attempts, two were able to successfully flash. I have verified all my connectivity.
What really gets me is the inconsistency - why would ~2 of 40 attempts work, but the other 38 fail? Any ideas on how to fix this issue?
Thanks in advance!
Signal integrity issues?
A pull-up or pull-down that isn't pulling?
More items connected and drawing current so more noisy supply voltage?
I appreciate the response. I had initially considered signal integrity issues. I have triple-checked all my connections and they seem sound. Furthermore, the fact that I flashed successfully numerous times (with the new connectivity setup) leads me to believe it is not a signal issue. I suppose there is the possibility someone came into my office during those few hours and changed my settings in uVision4, but I've triple-checked all those as well :)