TL;DR: It seems that J-Link RTT Viewer in versions greater than 6.14g have a bug. If debugging session is stopped and restarted RTT Viewer console comes blank and no RTT Log statements are displayed. The bug is present in the latest J-Link Version.
Details:
Platform:
J-Link OB on Nordic nRF52-DK board with most recent firmware (tested on multiple boards). Windows 10 64Bit. Tested with Keil 5.23 and Eclipse using latest GNU ARM Eclipse plugin
Ways to reproduce:
Start a debugging session. When debugger breaks at main() launch RTT Viewer. Start the program, RTT logging works as usual. Stop and restart debugging session (when stopping make sure that debugger exits and RTT Viewer goes to reconnect dialog, i.e. press Ctrl+F5 in Keil). After restarting debug session RTT Viewer console will be blank despite that program emits RTT Log statements. Closing RTT Viewer and launching it again allows to see RTT Log from the first debug session of given launch.
The bug is present in the J-Link software versions > 6.14g, which is last unaffected version.
Workaround:
Copy J-Link RTT Viewer 6.14g .exe file on top of more recent one in J-Link installation folder.
I hope this gets patched in one of future J-Link software releases.
Details:
Platform:
J-Link OB on Nordic nRF52-DK board with most recent firmware (tested on multiple boards). Windows 10 64Bit. Tested with Keil 5.23 and Eclipse using latest GNU ARM Eclipse plugin
Ways to reproduce:
Start a debugging session. When debugger breaks at main() launch RTT Viewer. Start the program, RTT logging works as usual. Stop and restart debugging session (when stopping make sure that debugger exits and RTT Viewer goes to reconnect dialog, i.e. press Ctrl+F5 in Keil). After restarting debug session RTT Viewer console will be blank despite that program emits RTT Log statements. Closing RTT Viewer and launching it again allows to see RTT Log from the first debug session of given launch.
The bug is present in the J-Link software versions > 6.14g, which is last unaffected version.
Workaround:
Copy J-Link RTT Viewer 6.14g .exe file on top of more recent one in J-Link installation folder.
I hope this gets patched in one of future J-Link software releases.