ST STM32F4DISCOVERY User Manual

DocID022256 Rev 4 19/42
UM1472 Hardware and layout
41
4.10 OSC clock
4.10.1 OSC clock supply
If PH0 and PH1 are only used as GPIOs instead of as a clock, then SB13 and SB14 are
closed and R24, R25 and R68 are removed.
• MCO from ST-LINK. From MCO of the STM32F103. This frequency cannot be
changed, it is fixed at 8 MHz and connected to PH0-OSC_IN of the STM32F407VGT6.
Configuration needed:
– SB13, SB14 OPEN
– R25
(a)
removed
– R68
(a)
soldered
• Oscillator onboard. From X2 crystal. For typical frequencies and its capacitors and
resistors, please refer to the STM32F407VGT6 Datasheet. Configuration needed:
– SB13, SB14 OPEN
– R25
(a)
soldered
– R68
(a)
removed
• Oscillator from external PH0. From external oscillator through pin 7 of the P2
connector. Configuration needed:
– SB13 closed
– SB14 closed
– R25 and R68 removed
4.10.2 OSC 32 KHz clock supply
If PC14 and PC15 are only used as GPIOs instead of as a clock, then SB15 and SB16 are
closed, and R21 and R22 are removed.
• Oscillator onboard. From X1 Crystal (not provided). Configuration needed:
– SB15, SB16 OPEN
– C16, C27, R21 and R22 soldered.
• Oscillator from external PC14. From external oscillator trough the pin 9 of P2
connector. Configuration needed:
– SB16 closed
– SB15 closed
– R21 and R22 removed
a. As the frequency supplied by X2 is the same as MCO (8 MHz) R25 and R68 are soldered.

ST STM32F4DISCOVERY Specifications

General

Brand	ST
Model	STM32F4DISCOVERY
Category	Microcontrollers
Language	English