BMD-34 / 38 EVK - User guide
UBX-19033356 - R06
Hardware description
Page 7 of 20
C1-Public
2.1.2
USB peripheral power
VBUS Power from the USB Peripheral interface on the BMD-34 may be used to power the
BMD-34-
EVAL by moving SW7 to the “HV” setting. This enables the internal high
-voltage
regulator (LDO or DC-DC). When in the HV setting, the power switch SW6 should be left in the
OFF position, especially if any of the protection diodes are bypassed.
Figure 3: Schematic
–
Power supply
2.2
Reset
The BMD-34 module has a configurable hardware reset. P0.18 is assumed to be used as the
reset pin for all BMD-34 and Nordic example projects, and thus the evaluation board hardware
is configured to use P0.18 as a reset. The Reset button can be configured to connect to an
input on the interface IC or to directly connect to P0.18.
The reset button is connected to the IC used for the J-Link interface by default. Pressing reset
while the interface IC is powered will cause a momentary reset signal on the
RESET_N
output
of the interface IC, which is connected via solder jumper to P0.18 of the BMD-34 module. If the
reset button is held down during EVK power on, it will cause the interface IC to enter its
bootloader mode, allowing either SEGGER J-Link or mbed programmer firmware to be
programmed.
