[SOLVED] SWO viewer will not accept CPU selection

DaveN · Apr 16th 2020, 9:14pm

PPS: Mysteriously, it started accepting the CPU selection.
I set the correct CPU clock speed.
Now the choices for SWO baud rate are strange - can't enter 60 (for 60000 as SWO is setup).
And cannot connect...

Jlink base, STM32F437VI
In Jlink SWO viewer, CPU window is blank.
Selecting correct (connected, operating, debugable) CPU does not do anything, window remains blank.
How do I get this to work?
Thanks!
Best Regards, Dave

PS: Version 6.70, Windows 10 64-bit, USB-connected.
Debugging via STMCubeIDE works OK.
Except I cannot see SWO printf output

SEGGER - Fabian · Apr 17th 2020, 9:46am

Hi,
Thank you for your inquiry.
Such an issue is not known to us.

A SWO speed < 1 MHz is very unlikely. Please be aware that the target interface speed (TIF) does not equal the SWO speed.

The SWO viewer is supposed to work out-of-the-box for STM32F4 devices and without any further settings needed.
Could you please try the following:
1) Open the SWO Viewer
2) Select the correct device (STM32F437VI)
3) Click on the "Measure" button.
4) Click on "OK"

This should show you the correct SWO data.

If you do not read the expected data:
1) Do you use custom hardware or an evaluation board? In the latter case which one?
2) If custom hardware, do you experience the same problem on an evaluation board?

3) Could you please send us a J-Link log file? How to enable:
wiki.segger.com/J-Link_DLL#Enable_J-Link_Log_File
4) Is the SWO pin of the device connected to the debug probe?

Best regards,
Fabian

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