10. Debugging
The EFM8BB2-SLSTK2021A contains an integrated debugger, which can be used to download code and debug the Busy Bee EFM8
MCU. In addition to programming the MCU on the kit, the debugger can also be used to program and debug external Silicon Labs
EFM8 devices.
10.1 Debug Modes
Programming external devices is done by connecting to a target board through the provided Debug IN/OUT Connector, and by setting
the debug mode to [
Out
]. The same connector can also be used to connect an external debugger to the EFM8 MCU on the kit, by
setting the debug mode to [
In
]. A summary of the different supported debug modes is given in
Table 10.1 Debug Modes on page 18
Table 10.1. Debug Modes
Mode
Description
Debug MCU
In this mode the on-board debugger is connected to the EFM8 on the EFM8BB2-SLSTK2021A.
Debug In
In this mode, the on-board debugger is disconnected, and an external debugger can be connected to debug the
EFM8 on the EFM8BB2-SLSTK2021A.
Debug Out
In this mode, the on-board debugger can be used to debug an EFM8 mounted on a custom board.
Selecting the active debug mode is done with a drop-down menu in the Kit Manager tool, which is available through Simplicity Studio.
When using the debug adapter in the [
Out
] mode, the end device must be manually detected before debugging and programming. To
do this:
1. Right-click on the kit from the Simplicity Studio launch screen and select [
Select Target Part...
].
2. If needed, select the appropriate [
Target Interface
] for the external device. For example, EFM8 devices will use the [
C2
] selection.
3. In the same dialog, click the [
Detect Target
] button.
4. Click [
OK
] to close the dialog. The external target can now be debugged and programmed.
10.2 Debugging during Battery Operation
When the EFM8 is powered by battery and the J-Link USB is still connected, the on-board debug functionality is available. If the USB
power is disconnected, the Debug In mode will stop working.
To enable debugging when the USB cable is removed, connect an external debugger to the MCU Debug Header in the top right corner
of the EFM8BB2-SLSTK2021A instead of the Debug IN/OUT Connector. This header is connected directly to the EFM8's debug inter-
face. The pinout of this header is shown in the Connectors chapter.
UG237: EFM8BB2-SLSTK2021A User's Guide
Debugging
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