ST STM32F301 6 Series Reference Manual page 94

Reset and clock control (RCC)
FCLK acts as Cortex
®
Cortex -M4 MCUs and MPUs programming manual
7.2.1 HSE clock
The high speed external clock signal (HSE) can be generated from two possible clock
sources:
•
HSE external crystal/ceramic resonator
•
HSE user external clock
The resonator and the load capacitors have to be placed as close as possible to the
oscillator pins to minimize output distortion and startup stabilization time. The loading
capacitance values must be adjusted according to the selected oscillator.
Clock source
External clock
Crystal/Ceramic
resonators
94/874
®
-M4F free-running clock. For more details, refer to the STM32
Figure 12. HSE/ LSE clock sources
RM0366 Rev 5
(PM0214).
Hardware configuration
OSC_IN OSC_OUT
GPIO
External
source
OSC_IN OSC_OUT
C
L1
Load
capacitors
RM0366
MSv31915V1
C
L2
MSv31916V1