Clock

Clock

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Sources:

1. Crystal Oscillator (External)
2. The RC Oscillator (Internal)
3. The PLL (Phase Locked Loop) (Internal)

The System Clock layout

Peripheral Clock Configuration

• By default, peripheral clock of most peripheral will be disabled to save power
• Peripheral won’t take or respond to configuration until it’s enabled

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• Clock output setting for GPIO

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I2S clock source

APB_CLK source

CPU_CLK source