Embedded-clock Structure

Proper clock signals are required for normal CPU operation, including the cclk clock used by the ARM core and the pclk clock used by the chip peripherals.

CPU clock structure:

 

The Clock generation units include the crystal oscillator, the PLL oscillator, And the VPB divider.

 

• Crystal Oscillator

You can use an internal crystal oscillator to generate clock signals, or introduce clock signals from outside.

• PLL)

The clock signal output by the crystal oscillator can get a higher system clock (cclk) through the PLL increase ).

• VPB Divider

The VPB divider determines the relationship between the CPU clock (cclk) and the clock (pclk) used by the peripheral device.

Purpose: Use the VPB bus to provide the required pclk clock for peripherals to work at an appropriate speed. This reduces power consumption when applications do not require any peripherals to run at full speed.