ST STM32F072 User manual

March 2020 UM1690 Rev 3 1/27
UM1690
User manual
Discovery kit for STM32F0 Series microcontrollers
with STM32F072RB
Introduction
The STM32F072 Discovery kit (32F072BDISCOVERY) helps users to discover the full
features of the STM32F0 Series and develop their applications. It is based on an
STM32F072RBT6 microcontroller and includes an ST-LINK/V2 embedded debug tool
interface, ST MEMS gyroscope, LEDs, push-buttons, linear touch sensor, touch keys, RF
EEPROM connector and a USB Mini-B connector.
Figure 1. STM32F072 Discovery kit
Picture is not contractual.
www.st.com

Contents UM1690
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Contents
1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Product marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Codification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Development environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Development toolchains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Demonstration software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Hardware layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1 Embedded ST-LINK/V2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1.1 Using ST-LINK/V2 to program/debug the STM32F072 on board . . . . . 12
5.1.2 Using ST-LINK/V2 to program/debug an external STM32 application . . 13
5.2 Power supply and power selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.3 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.4 Pushbuttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.5 Linear touch sensor / touch keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.6 USB device support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.7 BOOT0 configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.8 Embedded USB Bootloader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.9 Gyroscope MEMS (ST MEMS I3G4250D) . . . . . . . . . . . . . . . . . . . . . . . . 16
5.10 JP2 (Idd) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.11 Extension and RF EEPROM connector . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.12 OSC clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.12.1 OSC clock supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.12.2 OSC 32 KHz clock supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.13 Solder bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.14 Extension connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

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UM1690 Contents
3
6 Mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

List of tables UM1690
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List of tables
Table 1. Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2. Codification explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 3. ON/OFF conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 4. Jumper states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Table 5. Debug connector CN4 (SWD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 6. Extension and RF EEPROM connector (CN3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Table 7. Solder bridges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 8. MCU pin description versus board function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Table 9. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

UM1690 Rev 3 5/27
UM1690 List of figures
5
List of figures
Figure 1. STM32F072 Discovery kit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Hardware block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 3. Top layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 4. Bottom layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 5. STM32F072 Discovery kit connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 6. ST-LINK connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 7. Extension and RF EEPROM connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 8. STM32F072 Discovery kit mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Features UM1690
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1 Features
The STM32F072 Discovery kit offers the following features:
•STM32F072RBT6 microcontroller based on the Arm®(a) Cortex®-M0 processor,
featuring 128 Kbytes of Flash memory, 16 Kbytes of SRAM in an LQFP64 package
•USB FS with Mini-B connector
•I3G4250D ST MEMS motion sensor 3-axis digital output gyroscope
•One linear touch sensor or four touch keys
•Six LEDs:
– LD1 (red/green) for USB communication
– LD2 (red) for 3.3 V power on
– Four user LEDs: LD3 (red), LD4 (orange), LD5 (green) and LD6 (blue)
•Two push-buttons (user and reset)
•RF EEPROM daughterboard connector
•Extension header for LQFP64 I/Os for quick connection to a prototyping board and
easy probing
•On-board ST-LINK/V2 with switch to use the kit as a standalone ST-LINK/V2 (with
SWD connector for programming and debugging)
•Flexible power supply options:
– USB bus or external 5 V supply voltage
•Power supply output for external applications: 3 V and 5 V
•Comprehensive free software including a variety of examples, part of STM32CubeF0
or STM32SnippetsL0 packages or STSW-STM32139 for legacy Standard Libraries
usage
a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and or elsewhere.

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UM1690 Ordering information
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2 Ordering information
To order the 32F072BDISCOVERY Discovery kit, refer to Table 1. Additional information is
available from the datasheet and reference manual of the target STM32.
2.1 Product marking
Evaluation tools marked as “ES” or “E” are not yet qualified and are therefore not ready to
be used as reference designs or in production. Any consequences arising from such usage
will not be at ST’s charge. In no event will ST be liable for any customer usage of these
engineering sample tools as reference designs or in production.
‘E’ or ‘ES’ marking examples of location:
•on the targeted STM32 that is soldered on the board (For an illustration of STM32
marking, refer to the section ‘Package information’ of the STM32 datasheet at
www.st.com).
•next to the evaluation tool ordering part number, that is stuck or silkscreen printed on
the board
2.2 Codification
The meaning of the codification is explained in Table 2.
Table 1. Ordering information
Order code Board reference Target STM32
STM32F072B-DISCO MB1076 STM32F072RBT6
Table 2. Codification explanation
32XXYYZDISCOVERY Description Example: 32F072BDISCOVERY
32XX MCU series in STM32 32-bit Arm
Cortex MCUs STM32F0 Series
YY MCU product line in the series STM32F072
ZSTM32 Flash memory size:
– B for 128 Kbytes 128 Kbytes
DISCOVERY Discovery kit Discovery kit

Development environment UM1690
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3 Development environment
3.1 System requirements
•Windows®OS (7, 8 and 10), Linux®64-bit or macOS®(a) (b)
•USB Type-A to Mini-B cable
3.2 Development toolchains
•IAR™ - EWARM(c)
•Keil®- MDK-ARM(c) (d)
•STMicroelectronics - STM32CubeIDE
3.3 Demonstration software
The demonstration software, included in the STM32Cube MCU Package, is preloaded in the
STM32 Flash memory for easy demonstration of the device peripherals in standalone mode.
The latest versions of the demonstration source code and associated documentation can be
downloaded from the www.st.com/stm32f0-discovery webpage.
4 Conventions
Table 3 provides the definition of some conventions used in the present document.
a. macOS®is a trademark of Apple Inc. registered in the U.S. and other countries.
b. All other trademarks are the property of their respective owners.
c. On Windows®only.
d. Free MDK-ARM for Arm®Cortex®-M0/M0+ cores.
Table 3. ON/OFF conventions
Convention Definition
Jumper JPx ON Jumper fitted
Jumper JPx OFF Jumper not fitted
Solder bridge SBx ON SBx connections closed by solder
Solder bridge SBx OFF SBx connections left open

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UM1690 Hardware layout
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5 Hardware layout
The STM32F072 Discovery kit is designed around the STM32F072RBT6 microcontroller in
a 64-pin LQFP package.
Figure 2 illustrates the connections between the STM32F072RBT6 and its peripherals (ST-
LINK/V2, ST MEMS gyroscope I3G4250D, LEDs, push buttons, linear touch sensor, touch
keys, RF EEPROM connector and a USB Mini-B connector).
Figure 3 and Figure 4 help to locate these features on the STM32F072 Discovery board.
Figure 2. Hardware block diagram
MS33267V2
Embedded
ST-LINK/V2
STM32F072RBT6
I/O I/O
I/O RESET
LEDs
LD3 to LD6
I3G4250D
B2
RESET
B1
USER
Mini-USB
Mini-USB
SWD
Header
Header
EXT/RF-EEP
Linear touch
sensor

Hardware layout UM1690
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Figure 3. Top layout
MSv33268V2
ST-LINK/V2
USB ST-LINK USB USER
LD1
COM LED
LD2
PWR LED
5 V power supply
input/output
CN5
ST-LINK/DISCOVERY
selector
LD3 (red LED)
LD5 (green LED)
LD6 (blue LED)
B2
reset button
B1
user button
Linear touch sensor
/touchkeys
STM32F072RBT6
JP2
Idd measurement
LD4
(orange LED)
CN4
SWD connector
3 V power supply
input/output
CN3 extension or
RF EEPROM connector

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UM1690 Hardware layout
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Figure 4. Bottom layout
MSv33269V2
SB5
STM_RST
JP2
SB1, 3, 6, 8
Reserved
P2 connector
SB11,12
RX, TX
SB2, 4, 7, 9
Default
SB16
VDDIO2
SB19
MCO
SB20, 23
USB-USER
SB22
B2-RESET
P1 connector
SB10
NRST
SB15
VBAT
SB13, 14
X2 crystal
SB17, 18
X3 crystal
SB21 B1-USER
SB24, 25 GND, VDD
SB26 VDDA
SB27-32
Touch sensor

Hardware layout UM1690
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5.1 Embedded ST-LINK/V2
The ST-LINK/V2 programming and debugging tool is integrated on the STM32F072
Discovery kit. The embedded ST-LINK/V2 can be used in 2 different ways according to the
jumper states (see Table 4):
•Program/debug the MCU on board
•Program/debug an MCU in an external application board using a cable connected to
SWD connector CN4
The embedded ST-LINK/V2 supports only SWD for STM32 devices. For information about
debugging and programming features, refer to user manual UM1075 (ST-LINK/V2 in-circuit
debugger/programmer for STM8 and STM32), which describes in detail all the ST-LINK/V2
features.
5.1.1 Using ST-LINK/V2 to program/debug the STM32F072 on board
To program the STM32F072 on board, simply plug in the two jumpers on CN5, as shown in
Figure 5 in pink, but do not use the CN4 connector as that could disturb communication with
the STM32F072RBT6 of the STM32F072 Discovery kit.
Figure 5. STM32F072 Discovery kit connections
Table 4. Jumper states
Jumper state Description
Both CN5 jumpers ON ST-LINK/V2 functions enabled for on board programming (default)
Both CN5 jumpers OFF ST-LINK/V2 functions enabled for application through external CN4
connector (SWD supported)

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UM1690 Hardware layout
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5.1.2 Using ST-LINK/V2 to program/debug an external STM32 application
It is very easy to use the ST-LINK/V2 to program the STM32 on an external application.
Simply remove the 2 jumpers from CN5 as shown in Figure 6, and connect the application
to the CN4 debug connector according to Table 5.
Note: SB10 must be OFF if CN4 pin 5 is used by the external application.
Figure 6. ST-LINK connections
Table 5. Debug connector CN4 (SWD)
Pin CN4 Designation
1 VDD_TARGET VDD from application
2 SWCLK SWD clock
3 GND Ground
4 SWDIO SWD data input/output
5 NRST Reset of the target MCU
6 SWO Reserved

Hardware layout UM1690
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5.2 Power supply and power selection
The power supply is provided either by the host PC through the USB ST-LINK or USB
USER connector, or by an external 5 V power supply.
The D1 and D2 diodes protect the 5 V and 3 V pins from external power supplies:
•5 V and 3 V can be used as output power supplies when another application board is
connected to pins P1 and P2.
In this case, the 5 V and 3 V pins deliver a 5 V or 3 V power supply and the power
consumption must be lower than 100 mA.
•5 V can also be used as input power supplies, for instance when the USB connector is
not connected to the PC.
In this case, the STM32F072 Discovery kit must be powered by a power supply unit or
by an auxiliary equipment complying with standard EN-60950-1: 2006+A11/2009, and
must be Safety Extra Low Voltage (SELV) with limited power capability.
5.3 LEDs
•LD1 COM: LD1 default status is red. LD1 turns to green to indicate that
communications are in progress between the PC and the ST-LINK/V2.
•LD2 PWR: This red LED indicates that the board is powered.
•User LD3: This red user LED is connected to the I/O PC6 of the STM32F072RBT6.
•User LD4: This orange user LED is connected to the I/O PC8 of the STM32F072RBT6.
•User LD5: This green user LED is connected to the I/O PC9 of the STM32F072RBT6.
•User LD6: This blue user LED is connected to the I/O PC7 of the STM32F072RBT6.
5.4 Pushbuttons
B1 USER: User and Wake-Up button connected to the I/O PA0 of the STM32F072RBT6.
B2 RESET: The push button connected to NRST is used to reset the STM32F072RBT6.

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5.5 Linear touch sensor / touch keys
To demonstrate touch sensing capabilities, the STM32F072 Discovery kit includes a linear
touch sensor, which can be used either as a 3-position linear touch sensor or as 4 touch
keys. Both functions are illustrated in the demonstration software.
3 pairs of I/O ports are assigned to the linear touch sensor / touch keys. Each pair must
belong to the same analog switch group:
•PA2, PA3 (group 1)
•PA6, PA7 (group 2)
•PB0, PB1 (group 3)
To minimize the noise, these pairs are dedicated to the linear touch sensor and the touch
keys and are not connected to external headers. To design a touch sensing application,
refer to the following documentation and firmware:
•For details concerning I/O ports, refer to the STM32F072RBT6 datasheet.
•For information on software development, see DISCOVER application software on
www.st.com/stm32f0-discovery.
•STM32 touch sensing library available from www.st.com/stm32f0-discovery.
5.6 USB device support
The STM32F072RBT6 MCU is also used to drive the second USB Mini-B connector (USB
USER) which allows the board to be used as a USB Device. The STM32F072 Discovery kit
can then act as a USB joystick, mouse, or other similar device. If both USBs are connected,
diodes D1 and D2 protect the board and use the power from the USB ST-LINK.
The board can be powered through this USB USER connector, in which case LED2 PWR
lights up, LED1 COM blinks and it can run an application in standalone mode.
The STM32F072RBT6 MCU controls the USB USER through PA11 and PA12.
5.7 BOOT0 configuration
BOOT0 is at level “0” through pull-down resistor R33. If the user wants to set BOOT0 at
level “1”, it can be configured by setting a jumper between P2.6 (BOOT0) and P2.5 (VDD).
This facility is offered for fast and instantaneous configuration.
Note: If it is needed to set BOOT0 at level "1" continuously, then unsolder resistor R33 to avoid a
consumption of 6 mA while connecting pin P2.6 (BOOT0) and P2.5 (VDD) with a jumper or
with a wire.
5.8 Embedded USB Bootloader
The STM32F072 line microcontrollers embed a bootloader allowing the programming of
blanked device or the upgrade device firmware over the USB without the need of a specific
programmer. When using this Discovery kit, the STM32F072RBT6 MCU firmware can be
thus programmed through the second USB Mini-B connector (USER USB).
To program the microcontroller Flash memory using this approach, a jumper must be set
between BOOT0 (P2.6) and VDD (P2.5), and a cable connected between the USER USB

Hardware layout UM1690
16/27 UM1690 Rev 3
connector of the board and a PC. On the PC side, it is required to use the Device Firmware
Upgrade Utility named "DfuSe". This software (STSW-STM32080) and its associated user
manual (UM0412) are available from www.st.com.
Several application notes are also available on that topic.
•AN2606: STM32 microcontroller system memory boot mode
•AN3156: USB DFU protocol used in the STM32 bootloader
Note: ST-LINK utilities must not be used when the DFU utility is running.
5.9 Gyroscope MEMS (ST MEMS I3G4250D)
The I3G4250D is an ultra-compact, low-power, three-axis angular rate sensor. It includes a
sensing element and an IC interface able to provide the measured angular rate to the
external world through the I2C/SPI serial interface.
The I3G4250D has dynamically-user-selectable full scales:
•±245 dps
•±500 dps
•±2000 dps
The I3G4250D is capable of measuring rates.
The STM32F072RBT6 MCU controls this motion sensor through the SPI interface.
5.10 JP2 (Idd)
Jumper JP2, labeled Idd, allows the consumption of STM32F072RBT6 to be measured by
removing the jumper and connecting an ammeter.
•Jumper ON: STM32F072RBT6 is powered (default).
•Jumper OFF: an ammeter must be connected to measure the STM32F072RBT6
current, (if there is no ammeter, the STM32F072RBT6 is not powered).
5.11 Extension and RF EEPROM connector
This connector is able to accept an extension board or the RF EEPROM board ANT7-
M24LR-A (see application note How to design an antenna for dynamic NFC tags (AN2972)
for more details).
Figure 7. Extension and RF EEPROM connector

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UM1690 Hardware layout
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Table 6. Extension and RF EEPROM connector (CN3)
Pin CN3 Designation
1 I2C SDA Data signal for I2C
2 NC Not connected
3 I2C SCL Clock signal for I2C
4 EXT_RESET Reset signal for extension board
5 3V 3 volt power supply
6 NC Not connected
7 GND Ground
8 5V 5 volt power supply

Hardware layout UM1690
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5.12 OSC clock
By default, the STM32F072RBT6 clock source is the high-speed internal (HSI) RC
oscillator. Other clock sources are described hereunder.
5.12.1 OSC clock supply
If PF0 and PF1 are only used as GPIOs instead of clock, then SB17 and SB18 are ON and
R36 and R37 are removed (SB19 must be OFF).
•MCO from ST-LINK (from MCO of the STM32F103). This frequency cannot be
changed, it is fixed at 8 MHz and connected to PF0-OSC_IN of the STM32F072RBT6.
The required configuration is:
– SB19 ON and SB17 OFF
– R36 removed
•Oscillator on board (from X3 crystal, not provided). For typical frequencies and its
capacitors and resistors, refer to the STM32F072RBT6 datasheet.
The required configuration is:
– SB17, SB18, SB19 OFF
– X3, R36, R37, C22, C23 soldered
•Oscillator from external PF0 (from external oscillator through pin 7 of the P1
connector).
The required configuration is:
–SB17ON
–SB19OFF
– R36 removed
5.12.2 OSC 32 KHz clock supply
If PC14 and PC15 are only used as GPIOs instead of clock, then SB13 and SB14 are ON,
and R34 and R35 are removed.
•Oscillator on board (from X2 crystal, not provided).
The required configuration is:
– SB13, SB14 OFF
– X2, C19, C20, R34, R35 soldered
•Oscillator from external PC14 (from external oscillator trough the pin 5 of P1
connector).
The required configuration is:
–SB14ON
– R35 removed

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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

Hardware layout UM1690
20/27 UM1690 Rev 3
5.14 Extension connectors
The male headers P1 and P2 can connect the STM32F072 Discovery kit to a standard
prototyping/wrapping board. STM32F072RBT6 GPIOs are available on these connectors.
P1 and P2 can also be probed by an oscilloscope, logical analyzer or voltmeter.
Table 8. MCU pin description versus board function
MCU pin Board function
Main function LQFP64 pin num. System Linear touch sensor I3G4250D EXT/ RF-E2P Pushbutton LED USB USER Free I/O Power supply CN3 CN4 P1 P2 SBx(1)
BOOT0 60
BOOT0
- - - - - - - - - - -
6
-
NRST 7
NRST
- - -
RESET
- - - - -
510
- -
PA0 14
- - - -
USER
- - - - - -
15
- -
PA1 15
- - - - - - -
PA1
- - -
16
- -
PA2 16
-
TS_G1_IO3
- - - - - - - - -
17
-
SB27
PA3 17
-
TS_G1_IO4
- - - - - - - - -
18
-
SB28
PA4 20
- - - - - - -
PA4
- - -
21
- -
PA5 21
- - - - - - -
PA5
- - -
22
- -
PA6 22
-
TS_G2_IO3
- - - - - - - - -
23
-
SB29
PA7 23
-
TS_G2_IO4
- - - - - - - - -
24
-
SB30