User Manual

Page 8
nRF51 Development Kit User Guide v1.0
4 Interface MCU
Figure 3 Interface MCU
4.1 IF Boot/Reset button
The nRF51 DK board is equipped with a boot/reset button (SW5). This button is connected to the interface
MCU on the board and have two functions:
• Reset button for the nRF device.
• Enter boot loader mode of the interface MCU.
During normal operation the button will function as a reset button for the nRF device. To enter boot loader
mode of the Interface MCU, the button must be pressed while the board is powered until the LED LD5 starts
to blink. This is done by pressing the reset button and power cycle the board, either by disconnecting and
reconnecting the USB cable or toggle the power switch (SW6).
Interface MCU
IF BOOT/RESET button
Power switch
LD5