STMicroelectronics UM1079, User Manual

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UM1079 Hardware and layout
37
4.8 Solder bridges
Table 6. Solder bridges
Bridge State
(1)
Description
SB18,20
(X3 crystal)
(2)
ON
PH0, PH1 are connected to P1 (X3, C21, C22, R30 must not
be fitted).
OFF
X3, C21, C22 and R30 provide a clock as shown in Section 7:
Electrical schematics .
PH0, PH1 are disconnected from P1.
SB7,9,11,13
(DEFAULT)
ON Reserved, do not modify.
SB6,8,10,12
(RESERVED)
OFF Reserved, do not modify.
SB1,2,14
(IDD_Measurement)
ON
PA0, PA4, PC13 are used by the I
DD
measurement.
JP1 ON.
OFF
PA0, PA4, PC13 are available and IDD module cannot be
used JP1 OFF.
SB15,16
(X2 crystal)
OFF
X2, C16, C17 and R28 deliver a 32 KHz clock.
PC14, PC15 are not connected to P1.
ON
PC14, PC15 are only connected to P1. Do not remove X2,
C16, C17, R28.
SB5
(B2-RESET)
ON
B2 Pushbutton is connected to the NRST pin of the
STM32L152 MCU.
OFF
B2 Pushbutton is not connected the NRST pin of the
STM32L152 MCU.
SB4
(B1-USER)
ON B1 Pushbutton is connected to PA0.
OFF B1 Pushbutton is not connected to PA0.
SB21
(VDD powered from 3 V)
ON V
DD
is powered from 3 V, SB22 must be OFF.
OFF V
DD
is not powered from 3 V, SB22 must be ON.
SB22
(Battery enable)
OFF
V
DD
is not powered by the CR2032 battery, SB21 must be
ON.
ON V
DD
is powered by the CR2032 battery, SB21 must be OFF.
SB100 (NRST)
ON
The NRST signal of the CN2 connector is connected to the
NRST pin of the STM32L152RCT6.
OFF
The NRST signal of the CN2 connector is not connected to the
NRST pin of the STM32L152RCT6.
SB101 (SWO)
ON The SWO signal of the CN2 connector is connected to PB3.
OFF The SWO signal is not connected.
SB102 (STM_RST)
OFF No incidence on STM32L152RCT6 NRST signal.
ON STM32L152RCT6 NRST signal is connected to GND.