ST 32F072BDISCOVERY, User Manual, Page: 19 / 27

UM1690 Rev 3 19/27
UM1690 Hardware layout
26
5.13 Solder bridges
Table 7. Solder bridges
Bridge State
(1)
1. The default state is in bold.
Description
SB17,18 (X3 crystal)
ON
PF0, PF1 are connected to P1 (R36, R37 must not be fitted and SB19 must be
OFF).
OFF
X3, C22, C23, R36 and R37 provide a clock. PF0, PF1 are disconnected from
P1.
SB13,14 (X2 crystal)
ON PC14, PC15 are only connected to P1. Remove only R34, R35
OFF
X2, C19, C20, R34 and R35 deliver a 32 KHz clock. PC14, PC15 are not
connected to P1.
SB19 (MCO)
OFF MCO signal of STM32F103C8T6 is not used.
ON
MCO clock signal from STM32F103C8T6 is connected to OSC_IN of
STM32F072RBT6. (SB17 must be OFF).
SB2,4,7,9 (Default) ON Reserved, do not modify.
SB1,3,6,8 (Reserved) OFF Reserved, do not modify.
SB24,25 (GND,VDD) ON Reserved, do not modify.
SB11,12 (RX,TX) OFF Reserved, do not modify
SB27,28,29,30,31,32
(touch sensor)
OFF Reserved to the linear touch sensor. PA2,3,6,7 and PB0,1 are not available.
ON
PA2,3,6,7 and PB0,1 are available then remove R38,39,40 and C26,27,28. (the
linear touch sensor is not available)
SB20,23 (USB-
USER)
OFF Reserved to the USB USER CN2. PA11,12 are not available.
ON PA11,12 are available then remove R12,13. (the USB USER CN2)
SB21 (B1-USER)
ON B1 pushbutton is connected to PA0.
OFF B1 pushbutton is not connected to PA0.
SB22 (B2-RESET)
ON B2 pushbutton is connected to the NRST pin of the STM32F072RBT6 MCU.
OFF B2 pushbutton is not connected the NRST pin of the STM32F072RBT6 MCU.
SB10 (NRST)
ON
T_NRST pin of the STM32F103C8T6 (ST-LINK/V2) and CN4.5 are connected to
the NRST pin of the STM32F072RBT6 MCU.
OFF
T_NRST pin of the STM32F103C8T6 (ST-LINK/V2) and CN4.5 are not
connected to the NRST pin of the STM32F072RBT6 MCU.
SB5 (STM_RST)
OFF No incidence on STM32F103C8T6 (ST-LINK/V2) NRST signal.
ON STM32F103C8T6 (ST-LINK/V2) NRST signal is connected to GND.
SB15 (VBAT)
ON VBAT Power is supplied by VDD
OFF VBAT Power is supplied by P1.3 connector
SB16 (VDDIO2)
ON VDDIO2 Power is supplied by VDD
OFF VDDIO2 Power is supplied by P2.18 connector
SB26 (VDDA)
ON VDDA Power is supplied by VDD through L1 inductance.
OFF VDDA Power is supplied by P2.19 connector