Can Simplicity Studio 4 be set up to do the more advanced output to SWO rather than just a simple string, or if you want the more advanced features do you have to code it up yourself?
Or alternatively use another IDE like the IAR one?
The SWO output can be used to send program counter samples to the Energy Profiler. Selecting the Energy Profiler gives some information on that as well as in the file bsp_trace.c.
Also Application Note 0043 (an0043-efm32-debug-trace-capabilities.pdf) gives information on using the SWO output with both the IAR and Keil IDE.
This CF KB article gives detailed instructions on using the IAR IDE for advanced capabilities of the SWO output: http://community.silabs.com/t5/32-bit-MCU-Knowledge-Base/IAR-SWO-ITM/ta-p/146508
I hope the above is useful to you.