DocID024597 Rev 3 185/1693
RM0351 Reset and clock control (RCC)
253
characteristics” section in your device datasheet.
2. The ADC clock can be derived from the AHB clock of the ADC bus interface, divided by a programmable
factor (1, 2 or 4). When the programmable factor is ‘1’, the AHB prescaler must be equal to ‘1’.
6.2.1 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 in order to minimize output distortion and startup stabilization time. The
loading capacitance values must be adjusted according to the selected oscillator.
Figure 13. HSE/ LSE clock sources
Clock source Hardware configuration
External clock
Crystal/Ceramic
resonators
OSC_OUT
External
source
GPIO
OSC_IN
OSC_IN OSC_OUT
Load
capacitors
C
L2
C
L1