Osc Clock; Osc Clock Supply; Osc 32 Khz Clock Supply - ST STM32F3DISCOVERY User Manual

UM1570
6.10

OSC clock

6.10.1

OSC clock supply

The following information indicates all configurations for clock supply selection:
•
MCO from ST-LINK. From MCO of the STM32F103C8T6. This frequency cannot be
changed. It is fixed at 8 MHz and connected to the PF0-OSC_IN pin of the
STM32F303VCT6. Configuration needed:
–
–
• Oscillator on board. From X2 crystal (not provided). For typical frequencies,
capacitors, and resistors, refer to the STM32F303VCT6 datasheet. Configuration
needed:
–
–
•
Oscillator from external PF0. From the external oscillator through pin 5 of the P2
connector. Configuration needed:
–
–
•
No external oscillator. From the internal oscillator HSI only. PF0 and PF1 can be used
as GPIO. Configuration needed:
–
–
6.10.2

OSC 32 kHz clock supply

The following information indicates all the configurations for the 32 kHz clock supply
selection:
•
Oscillator on board. From X3 Crystal (not provided). Configuration needed:
–
–
•
Oscillator from external PC14. From the external oscillator through pin 7 of the P2
connector. Configuration needed:
–
–
•
No external oscillator. PC14 and PC15 can be used as GPIO. Configuration needed:
–
–
SB12 ON, SB17 and R33 OFF
SB18, R32, C22, C23, and X2 = do not care
SB12, SB17, and SB18 OFF
R32, R33, C22, C23, and X2 ON
SB12 OFF, SB17 ON, and R33 OFF
SB18, R32, C22, C23, and X2 = do not care
SB12 OFF, SB17 and SB18 ON, R32 and R33 OFF
C22, C23, and X2 = do not care
SB14 and SB16 OFF
R29, R30, C14, C26, and X3 ON
SB14 ON, R29 OFF
SB16, R30, C14, C26, and X3 = do not care
SB14 and SB16 ON, R29 and R30 OFF
C14, C26, and X3 = do not care.
UM1570 Rev 7
Hardware layout and configuration
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