Board Controller Power; Efr32 Reset - Silicon Laboratories UG319 User Manual

4.2 Board Controller Power

The board controller is responsible for important features such as the debugger and the Advanced Energy Monitor, 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 differ-
ent 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.
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UG319: EFR32FG14 2400/490 MHz 19 dBm Dual Band Radio Board and Wireless Starter Kit User's Guide
Power Supply and Reset
Rev. 1.00 | 15