STM32F10x Standard Peripherals Library  3.5.0
Functions
STM32F10x_System_Private_Functions
Stm32f10x_system

Functions

void SystemInit (void)
 Setup the microcontroller system Initialize the Embedded Flash Interface, the PLL and update the SystemCoreClock variable.
void SystemCoreClockUpdate (void)
 Update SystemCoreClock variable according to Clock Register Values. The SystemCoreClock variable contains the core clock (HCLK), it can be used by the user application to setup the SysTick timer or configure other parameters.

Function Documentation

void SystemCoreClockUpdate ( void  )

Update SystemCoreClock variable according to Clock Register Values. The SystemCoreClock variable contains the core clock (HCLK), it can be used by the user application to setup the SysTick timer or configure other parameters.

Note:
Each time the core clock (HCLK) changes, this function must be called to update SystemCoreClock variable value. Otherwise, any configuration based on this variable will be incorrect.
- The system frequency computed by this function is not the real frequency in the chip. It is calculated based on the predefined constant and the selected clock source:
  • If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*)
  • If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**)

(*) HSI_VALUE is a constant defined in stm32f1xx.h file (default value 8 MHz) but the real value may vary depending on the variations in voltage and temperature.

(**) HSE_VALUE is a constant defined in stm32f1xx.h file (default value 8 MHz or 25 MHz, depedning on the product used), user has to ensure that HSE_VALUE is same as the real frequency of the crystal used. Otherwise, this function may have wrong result.

  • The result of this function could be not correct when using fractional value for HSE crystal.
    Parameters:
    None
    Return values:
    None

Definition at line 306 of file system_stm32f10x.c.

void SystemInit ( void  )

Setup the microcontroller system Initialize the Embedded Flash Interface, the PLL and update the SystemCoreClock variable.

Note:
This function should be used only after reset.
Parameters:
None
Return values:
None

Definition at line 212 of file system_stm32f10x.c.