ST STM32F030 User manual

September 2013 DocID025097 Rev 1 1/39
UM1658
User manual
Discovery kit for STM32F030 Value Line microcontrollers
Introduction
The STM32F030 Value Line Discovery kit (32F0308DISCOVERY) helps you to discover the
device features and to develop your applications easily. It is based on STM32F030R8T6, an
STM32 F0 series 32-bit ARM®Cortex™-M0 microcontroller, and includes an ST-LINK/V2
embedded debug tool, LEDs, push buttons and a prototyping board.
Figure 1. 32F0308DISCOVERY
www.st.com

Contents UM1658
2/39 DocID025097 Rev 1
Contents
1 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Quick start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Getting started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 System requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Development toolchains supporting the 32F0308DISCOVERY . . . . . . . . . 6
2.4 Order code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Hardware and layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 STM32F030R8T6 microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4.2 Embedded ST-LINK/V2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2.1 Using ST-LINK/V2 to program/debug the STM32 F0 on board . . . . . . . 14
4.2.2 Using ST-LINK/V2 to program/debug an external STM32 application . . 15
4.3 Power supply and power selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.4 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.5 Push buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6 JP2 (Idd) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.7 OSC clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.7.1 OSC clock supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.7.2 OSC 32 KHz clock supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.8 Solder bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.9 Extension connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5 Connecting modules on the prototyping board . . . . . . . . . . . . . . . . . . 25
5.1 Mikroelektronica accessory boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2 ST MEMS “adapter boards”, standard DIL24 socket . . . . . . . . . . . . . . . . 28
5.3 Arduino shield boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6 Mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7 Electrical schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

DocID025097 Rev 1 3/39
UM1658 List of tables
3
List of tables
Table 1. ON/OFF conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 2. Jumper states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Table 3. Debug connector CN3 (SWD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 4. Solder bridge settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 5. MCU pin description versus board function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 6. Connecting using mikroBUS™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Table 7. Connecting using IDC10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Table 8. Connecting with a DIL24 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Table 9. Supported MEMS adapter boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 10. Connecting with Arduino shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Table 11. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

List of figures UM1658
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List of figures
Figure 1. 32F0308DISCOVERY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Hardware block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 3. Top layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 4. Bottom layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Figure 5. STM32F030R8T6 package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 6. STM32F030R8T6 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 7. Typical configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 8. 32F0308DISCOVERY connections image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Figure 9. ST-LINK connections image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 10. Using IDC10 and mikroBUS™ connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 11. DIL24 socket connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 12. Arduino shield board connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Figure 13. 32F0308DISCOVERY mechanical drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 14. 32F0308DISCOVERY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Figure 15. ST-LINK/V2 (SWD only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Figure 16. MCU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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UM1658 Conventions
38
1 Conventions
Table 1 provides the definition of some conventions used in the present document.
Table 1. ON/OFF conventions
Convention Definition
Jumper JP1 ON Jumper fitted
Jumper JP1 OFF Jumper not fitted
Solder bridge SBx ON SBx connections closed by solder
Solder bridge SBx OFF SBx connections left open

Quick start UM1658
6/39 DocID025097 Rev 1
2 Quick start
The STM32F030 Value Line Discovery kit is a low-cost and easy-to-use development kit to
quickly evaluate and start development with an STM32 F0 series microcontroller.
Before installing and using the product, please accept the Evaluation Product License
Agreement from www.st.com/stm32f0-discovery.
For more information on the STM32F030 Value Line Discovery kit and for demonstration
software, visit www.st.com/stm32f0-discovery.
2.1 Getting started
Follow the sequence below to configure the STM32F030 Value Line Discovery kit and
launch the DISCOVER application:
1. Check jumper position on the board, JP2 on, CN2 on (Discovery selected).
2. Connect the 32F0308DISCOVERY board to a PC with a USB cable ‘type A to mini-B’
through USB connector CN1 to power the board. Red LED LD1 (PWR) and LD2 (COM)
light up and green LED LD3 blinks.
3. Press user button B1 (bottom left corner of the board).
4. Observe how the green LED LD3 blinking changes according to USER button B1
clicks.
5. Each click on USER button B1 is confirmed by the blue LED LD4.
6. To study or modify the DISCOVER project related to this demo, visit
www.st.com/stm32f0-discovery and follow the tutorial.
7. Discover the STM32F0 features, download and execute programs proposed in the list
of projects.
8. Develop your own application using available examples.
2.2 System requirements
•Windows PC (XP, Vista, 7)
•USB type A to Mini-B USB cable
2.3 Development toolchains supporting the 32F0308DISCOVERY
•Altium®, TASKING™ VX-toolset
•ARM®, Atollic TrueSTUDIO®
•IAR™, EWARM (IAR Embedded Workbench®)
•Keil™, MDK-ARM™
2.4 Order code
To order the STM32F030 Value Line Discovery kit, use the order code
STM32F0308-DISCO.

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UM1658 Features
38
3 Features
The STM32F030 Value Line Discovery kit offers the following features:
•STM32F030R8T6 microcontroller featuring 64 KB Flash, 8 KB RAM in an LQFP64
package
•On-board ST-LINK/V2 with selection mode switch to use the kit as a standalone
ST-LINK/V2 (with SWD connector for programming and debugging)
•Board power supply: through USB bus or from an external 5 V supply voltage
•External application power supply: 3 V and 5 V
•Four LEDs:
– LD1 (red) for 3.3 V power on
– LD2 (red/green) for USB communication
– LD3 (green) for PC9 output
– LD4 (blue) for PC8 output
•Two push buttons (user and reset)
•Extension header for LQFP64 I/Os for quick connection to prototyping board and easy
probing.
•An additional board is provided with the kit which can be connected to the extension
connector for even easier prototyping and probing.
•A large number of free ready-to-run application firmware examples are available on
www.st.com/stm32f0-discovery to support quick evaluation and development.

Hardware and layout UM1658
8/39 DocID025097 Rev 1
4 Hardware and layout
The STM32F030 Value Line Discovery board is designed around the STM32F030R8T6
microcontroller in a 64-pin LQFP package.
Figure 2 illustrates the connections between the STM32F030R8T6 and its peripherals
(ST-LINK/V2, push button, LEDs and connectors).
Figure 3 and Figure 4 help you to locate these features on the STM32F030 Value Line
Discovery board.
Figure 2. Hardware block diagram
MSv31935V1
I/O
Mini
USB
LD3, PC9
B2
RST
RESET
I/OI/O
Header
SWD
Embedded
ST-LINK/V2
STM32F030R8T6
LED
Header
B1
USER
LD4, PC8
LED

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UM1658 Hardware and layout
38
Figure 3. Top layout
Note: Pin 1 of CN2, CN3, P1 and P2 connectors are identified by a square.
(red/green LED) LD2
COM
CN3
SWD connector
IDD measurement
ST-LINK/V2
B1 user button
B2 reset button
LD1 (red LED)
PWR
CN2
ST-LINK/DISCOVERY
selector
(green LED) LD3
LD4 (blue LED)
STM32F030R8T6
JP2
5V power supply
input output
3V power supply
input output
SB1 (VDD)
SB3 (B1-USER)
SB4 (B2-RESET)
MS31936V1
MB1134 revA
STM32F0308-DISCO

Hardware and layout UM1658
10/39 DocID025097 Rev 1
Figure 4. Bottom layout
SB6, SB8, SB10, SB12
MS30025V1
SB5, SB7, SB9, SB11
(RESERVED)
(DEFAULT)
SB20, SB21 (X3 crystal)
SB14, SB15 (RX, TX)
SB19 (NRST)
SB16, SB17 (X2 crystal)
SB13 (STM_RST)
SB22 (T_SWO)
SB18 (MCO)

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UM1658 Hardware and layout
38
4.1 STM32F030R8T6 microcontroller
The STM32F030R8T6 microcontroller incorporates the high-performance ARM
Cortex™-M0 32-bit RISC core operating at a 48 MHz frequency, high-speed embedded
memories (up to 64 Kbytes of Flash memory and up to 8 Kbytes of SRAM), and an
extensive range of enhanced peripherals and I/Os. All devices offer standard
communication interfaces (up to two I2Cs, up to two SPIs, and up to two USARTs), one
12-bit ADC, up to 6 general-purpose 16-bit timers and an advanced-control PWM timer.
Figure 5. STM32F030R8T6 package
The STM32F030R8T6 microcontroller operates in the -40 to +85 °C temperature range,
from a 2.4 V to 3.6 V power supply. A comprehensive set of power-saving modes allows the
design of low-power applications.
These features make the STM32F030R8T6 microcontroller suitable for a wide range of
applications such as application control and user interfaces, handheld equipment,
A/V receivers and digital TV, PC peripherals, gaming platforms, e-bikes, consumer
appliances, printers, scanners, alarm systems, video intercoms, and HVACs.
MS31938V1
STM32F030R8T6
64 Kbyte of Flash memory
8 Kbytes of SRAM
LQFP64 10 x 10 mm

Hardware and layout UM1658
12/39 DocID025097 Rev 1
Figure 6. STM32F030R8T6 block diagram
MSv32137V1
4 channels
3 compl. channels
BRK, ETR input as AF
4 ch., ETR as AF
1 channel as AF
2 channels
1 compl, BRK as AF
1 channel
1 compl, BRK as AF
1 channel
1 compl, BRK as AF
IR_OUT as AF
RX, TX,CTS, RTS,
CK as AF
RX, TX,CTS, RTS,
CK as AF
SCL, SDA, SMBA
(20 mA for FM+) as AF
SCL, SDA
as AF
@ VDD
@ VDDA
AHBPCLK
APBPCLK
ADCCLK
USARTCLK
HCLK
FCLK
PA[15:0]
PB[15:0]
PC[15:0]
PD2
PF[1:0]
PF[7:4]
@ VDDA
55 AF
MOSI,
MISO,
SCK,
NSS as AF
VDDA
VSSA
GP DMA
5 channels
CORTEX-M0 CPU
fHCLK = 48 MHz
Serial
Wire
Debug
NVIC
GPIO port A
GPIO port B
GPIO port C
GPIO port D
GPIO port F
EXT. IT
WKUP
SPI1
SPI2
SYSCFG IF
TIMER 6
DBGMCU
WWDG
APB
AHB
CRC
RESET &
CLOCK
CONTROL
TIMER 1
TIMER 3
TIMER 14
TIMER 15
TIMER 16
TIMER 17
USART1
USART2
I2C 1
I2C2
Power
Controller
XTAL OSC
4-32 MHz
IWDG
SUPPLY
SUPERVISION
POR/PDR
POWER
VOLT.REG
3.3 V TO 1.8 V
RC HS 14 MHz
RC HS 8 MHz
RC LS
PLL
Flash interface
Flash
up to
64 KB,
32 bits
Obl
SRAM
4 / 8 KB
Temp.
sensor
IF
12-bit
ADC1
SWCLK
SWDIO
as AF
MOSI/MISO,
SCK/NSS,
as AF
16
AD inputs
Bus matrix
@ VDDA
@ VDD
VDD18
POR
Reset
Int
VDD = 2.4 to 3.6 V
VSS
NRST
VDDA
VDD
OSC_IN (PF0)
OSC_OUT (PF1)
OSC32_IN (PC14)
OSC32_OUT (PC15)
TAMPER-RTC
(ALARM OUT)
RTC
RTC interface
XTAL32 kHz
@ VDD
SRAM
controller
AHB decoder

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UM1658 Hardware and layout
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4.2 Embedded ST-LINK/V2
The ST-LINK/V2 programming and debugging tool is integrated on the
32F0308DISCOVERY. The embedded ST-LINK/V2 can be used in 2 different ways
according to the jumper states (see Table 2):
•Program/debug the MCU on board,
•Program/debug an MCU in an external application board using a cable connected to
SWD connector CN3.
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.
Figure 7. Typical configuration
Table 2. Jumper states
Jumper state Description
Both CN2 jumpers ON ST-LINK/V2 functions enabled for on board programming (default)
Both CN2 jumpers OFF ST-LINK/V2 functions enabled for application through external CN3
connector (SWD supported)
MS19052V2
Hardware requirements:
- USB cable type A to mini-B
- computer with Windows XP, Vista or 7
Development toolchain:
Altium, TASKING VX-Toolset,
Atollic, TrueSTUDIO
IAR, EWARM
Keil, MDK-ARM

Hardware and layout UM1658
14/39 DocID025097 Rev 1
4.2.1 Using ST-LINK/V2 to program/debug the STM32 F0 on board
To program the STM32 F0 on board, simply plug in the two jumpers on CN2, as shown in
Figure 8 in red, but do not use the CN3 connector as that could disturb communication with
the STM32F030R8T6 of the 32F0308DISCOVERY.
Figure 8. 32F0308DISCOVERY connections image
CN2 jumpers on
CN3
SWD connector

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38
4.2.2 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 CN2 as shown in Figure 9, and connect your application
to the CN3 debug connector according to Table 3.
Note: SB19 and SB22 must be OFF if you use CN3 pin 5 in your external application.
Figure 9. ST-LINK connections image
Table 3. Debug connector CN3 (SWD)
Pin CN3 Designation
1 VDD_TARGET VDD from application
2 SWCLK SWD clock
3 GND Ground
4 SWDIO SWD data input/output
5 NRST RESET of target MCU
6 SWO Reserved
CN2 jumpers off
CN3
SWD connector
u
mpers off
C
N2
ju

Hardware and layout UM1658
16/39 DocID025097 Rev 1
4.3 Power supply and power selection
The power supply is provided either by the host PC through the USB cable, 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 power
consumption must be lower than 100 mA.
•5 V can also be used as input power supplies; for example, when the USB connector is
not connected to the PC.
In this case, the 32F0308DISCOVERY board must be powered by a power supply unit
or by auxiliary equipment complying with standard EN-60950-1: 2006+A11/2009, and
must be Safety Extra Low Voltage (SELV) with limited power capability.
4.4 LEDs
•LD1 PWR: Red LED indicates that the board is powered.
•LD2 COM: Tricolor LED (COM) advises on the communication status as follows:
– Slow blinking Red LED/Off: At power on before USB initialization
– Fast blinking Red LED/Off: After the first correct communication between PC and
STLINK/V2 (enumeration)
– Red LED On: When initialization between PC and ST-LINK/V2 is successfully
finished
– Green LED On: After successful target communication initialization
– Blinking Red/Green LED: During communication with target
– Red LED On: Communication finished and OK
– Orange LED On: Communication failure
•User LD3: Green user LED connected to the I/O PC9 of the STM32F030R8T6.
•User LD4: Blue user LED connected to the I/O PC8 of the STM32F030R8T6.
4.5 Push buttons
•B1 USER: User push button connected to the I/O PA0 of the STM32F030R8T6.
•B2 RESET: Push button used to RESET the STM32F030R8T6.
4.6 JP2 (Idd)
Jumper JP2, labeled Idd, allows the consumption of STM32F030R8T6 to be measured by
removing the jumper and connecting an ammeter.
•Jumper on: STM32F030R8T6 is powered (default).
•Jumper off: an ammeter must be connected to measure the STM32F030R8T6 current,
(if there is no ammeter, the STM32F030R8T6 is not powered).

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4.7 OSC clock
4.7.1 OSC clock supply
PF0 and PF1 can be used as GPIO or as HSE oscillator. By default these I/Os are
configured as GPIO, so SB16 and SB17 are closed, SB18 is open and R22, R23, C13 and
C14 are not populated.
An external HSE clock can be provided to the MCU in three ways:
•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 STM32F030R8T6.
Configuration needed:
– SB16, SB18 CLOSED
– R22, R23 removed
– SB17 OPEN
•Oscillator onboard. From X2 crystal (not provided). For typical frequencies and its
capacitors and resistors, please refer to the STM32F030R8T6 datasheet.
Configuration needed:
– SB16, SB17, SB18 OPEN
– R22, R23, C13, C14 soldered
•Oscillator from external PF0. From external oscillator through pin 7 of the P1
connector. Configuration needed:
– SB16, SB17 CLOSED
– SB18 OPEN
– R22 and R23 removed
4.7.2 OSC 32 KHz clock supply
PC14 and PC15 can be used as GPIO or as LSE oscillator. By default these I/Os are
configured as GPIO, so SB20 & SB21 are closed and X3, R24, R25 are not populated.
An external LSE clock can be provided to the MCU in two ways:
•Oscillator onboard. From X3 crystal (not provided). Configuration needed:
– SB20, SB21 OPEN
– C15, C16, R24 and R25 soldered.
•Oscillator from external PC14. From external oscillator trough the pin 5 of P1
connector. Configuration needed:
– SB20, SB21 CLOSED
– R24 and R25 removed

Hardware and layout UM1658
18/39 DocID025097 Rev 1
4.8 Solder bridges
Table 4. Solder bridge settings
Bridge State(1) Description
SB16,17
(X2 crystal)(2)
OFF X2, C13, C14, R22 and R23 provide a clock. PF0, PF1 are disconnected
from P1.
ON PF0, PF1 are connected to P1 (R22, R23 and SB18 must not be fitted).
SB6,8,10,12 (Default) ON Reserved, do not modify.
SB5,7,9,11 (Reserved) OFF Reserved, do not modify.
SB20,21
(X3 crystal)
OFF X3, C15, C16, R24 and R25 deliver a 32 KHz clock. PC14, PC15 are not
connected to P1.
ON PC14, PC15 are only connected to P1 (R24, R25 must not be fitted).
SB4
(B2-RESET)
ON B2 push button is connected to the NRST pin of the STM32F030R8T6
MCU.
OFF B2 push button is not connected the NRST pin of the STM32F030R8T6
MCU.
SB3
(B1-USER)
ON B1 push button is connected to PA0.
OFF B1 push button is not connected to PA0.
SB1
(VDD_3)
ON VDD_3 must be permanently connected to VDD for normal use.
OFF Reserved, do not modify.
SB14,15
(RX,TX)
OFF Reserved, do not modify.
ON Reserved, do not modify.
SB19
(NRST)
ON NRST signal of the CN3 connector is connected to the NRST pin of the
STM32F030R8T6 MCU.
OFF NRST signal of the CN3 connector is not connected to the NRST pin of the
STM32F030R8T6 MCU.
SB22
(T_SWO)
ON SWO signal of the CN3 connector is connected to PB3.
OFF SWO signal is not connected.
SB13
(STM_RST)
OFF No incidence on STM32F103C8T6 (ST-LINK/V2) NRST signal.
ON STM32F103C8T6 (ST-LINK/V2) NRST signal is connected to GND.
SB2
(BOOT0)
ON BOOT0 signal of the STM32F030R8T6 MCU is held low through a
510 Ohm pull-down resistor.
OFF BOOT0 signal of the STM32F030R8T6 MCU can be set high through a
10 KOhm pull-up resistor R27 to solder.
SB18
(MCO)(2)
ON Provides the 8 MHz for OSC_IN from MCO of STM32F030R8T6.
OFF See SB16, SB17 description.
1. Default SBx state is shown in bold.
2. OSC_IN clock comes from MCO if SB18 is ON and SB16,17 are OFF
and comes from X2 if SB18 is OFF and SB16,17 are ON.

DocID025097 Rev 1 19/39
UM1658 Hardware and layout
38
4.9 Extension connectors
The male headers P1 and P2 can connect the 32F0308DISCOVERY to a standard
prototyping/wrapping board. STM32F030R8T6 GPI/Os are available on these connectors.
P1 and P2 can also be probed by an oscilloscope, logical analyzer or voltmeter.
Table 5. MCU pin description versus board function
MCU pin Board function
Main
function
Alternate
functions
LQFP64
Push button
LED
SWD
OSC
Free I/O
Power supply
CN3
P1 P2
BOOT0 BOOT0 60 6
NRST NRST 7
RESET
NRST
510
PA0
USART1_CTS,
USART2_CTS,
ADC_IN0,
RTC_TAMP2,
WKUP1
14
USER
15
PA1
USART1_RTS,
USART2_RTS,
EVENTOUT,
ADC_IN1
15 16
PA2
USART1_TX,
USART2_TX,
TIM15_CH1,
ADC_IN2
16 17
PA3
USART1_RX,
USART2_RX,
TIM15_CH2,
ADC_IN3
17 18
PA4
SPI1_NSS,
USART1_CK
USART2_CK,
TIM14_CH1,
ADC_IN4
20 21
PA5 SPI1_SCK,
ADC_IN5 21 22

Hardware and layout UM1658
20/39 DocID025097 Rev 1
PA6
SPI1_MISO,
TIM3_CH1,
TIM1_BKIN,
TIM16_CH1,
EVENTOUT,
ADC_IN6
22 23
PA7
SPI1_MOSI,
TIM3_CH2,
TIM14_CH1,
TIM1_CH1N,
TIM17_CH1,
EVENTOUT,
ADC_IN7
23 24
PA8
USART1_CK,
TIM1_CH1,
EVENTOUT,
MCO
41 25
PA9
USART1_TX,
TIM1_CH2,
TIM15_BKIN,
I2C1_SCL
42 24
PA10
USART1_RX,
TIM1_CH3,
TIM17_BKIN,
I2C1_SDA
43 23
PA11
USART1_CTS,
TIM1_CH4,
EVENTOUT
44 22
PA12
USART1_RTS,
TIM1_ETR,
EVENTOUT
45 21
PA13 IR_OUT,
SWDIO 46
SWDIO
420
PA14
USART1_TX,
USART2_TX,
SWCLK
49
SWCLK
217
Table 5. MCU pin description versus board function (continued)
MCU pin Board function
Main
function
Alternate
functions
LQFP64
Push button
LED
SWD
OSC
Free I/O
Power supply
CN3
P1 P2