Is it possible to use the Energy Profiler with an EFM32 STK with code correlation to profile an external EFM32 device?
Yes, though this does require connecting all debug pins, including SWO and GND, from the STK to the external device, and setting the STK's debug mode to OUT. In order for the profiler to accurately measure current consumption, the external device must be powered by the VMCU rail of the STK. Additionally, the STK's MCU should be placed into a low power mode, such as EM4, in order to reduce its affect on the measurements.
If the external device is on its own STK, some following steps must be taken:
1) The external STK must have its debug mode set to IN.
2) The external STK must have its USB debug cable attached, powering the debug circuitry.
3) The external STK should be switched to battery power, with no battery connected, in order to prevent the STK from powering its MCU.
4) After selecting the debugging STK, the "Profile" button must be used within Simplicity Studio's IDE to download the code to the external device.
From here, code correlation should work with the Energy Profiler with the external device.