STMicroelectronics Discovery kit for STM32 F030 Value line - with STM32F030R8 MCU STM32F0308-DISCO STM32F0308-DISCO Data Sheet

Product codes
STM32F0308-DISCO
Page of 39
DocID025097 Rev 1
UM1658
Hardware and layout
38
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