4.2 Board Controller Power
The board controller is responsible for important features, such as the debugger and the AEM, and is powered exclusively through the
USB port in the top left corner of the board. This part of the kit resides on a separate power domain, so a different power source can be
selected for the target device while retaining debugging functionality. This power domain is also isolated to prevent current leakage from
the target power domain when power to the board controller is removed.
The board controller power domain is not influenced by the position of the power switch.
The kit has been carefully designed to keep the board controller and the target power domains isolated from each other as one of them
powers down. This ensures that the target EFR32 device will continue to operate in the
USB
and
BAT
modes.
4.3 EFR32 Reset
The EFR32 Wireless SoC can be reset by a few different sources:
• A user pressing the RESET button
• The on-board debugger pulling the #RESET pin low
• An external debugger pulling the #RESET pin low
In addition to the reset sources mentioned above, a reset to the EFR32 will also be issued during board controller boot-up. This means
that removing power to the board controller (unplugging the J-Link USB cable) will not generate a reset, but plugging the cable back in
will, as the board controller boots up.
UG431: EFR32xG22 2.4 GHz 6 dBm QFN32 Wireless Starter Kit User's Guide
Power Supply and Reset
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