Initialization and Configuration functions. More...

Functions
HAL_StatusTypeDef	HAL_RCC_DeInit (void)
	Resets the RCC clock configuration to the default reset state.
__weak HAL_StatusTypeDef	HAL_RCC_OscConfig (RCC_OscInitTypeDef *RCC_OscInitStruct)
	Initializes the RCC Oscillators according to the specified parameters in the RCC_OscInitTypeDef.
HAL_StatusTypeDef	HAL_RCC_ClockConfig (RCC_ClkInitTypeDef *RCC_ClkInitStruct, uint32_t FLatency)
	Initializes the CPU, AHB and APB buses clocks according to the specified parameters in the RCC_ClkInitStruct.

Detailed Description

Initialization and Configuration functions.

 ===============================================================================
           ##### Initialization and de-initialization functions #####
 ===============================================================================
    [..]
      This section provides functions allowing to configure the internal/external oscillators
      (HSE, HSI, LSE,CSI, LSI,HSI48, PLL, CSS and MCO) and the System buses clocks (SYSCLK, AHB3, AHB1
       AHB2,AHB4,APB3, APB1L, APB1H, APB2, and APB4).

    [..] Internal/external clock and PLL configuration
         (#) HSI (high-speed internal), 64 MHz factory-trimmed RC used directly or through
             the PLL as System clock source.
         (#) CSI is a low-power RC oscillator which can be used directly as system clock, peripheral
             clock, or PLL input.But even with frequency calibration, is less accurate than an
             external crystal oscillator or ceramic resonator.
         (#) LSI (low-speed internal), 32 KHz low consumption RC used as IWDG and/or RTC
             clock source.

         (#) HSE (high-speed external), 4 to 48 MHz crystal oscillator used directly or
             through the PLL as System clock source. Can be used also as RTC clock source.

         (#) LSE (low-speed external), 32 KHz oscillator used as RTC clock source.

         (#) PLL , The RCC features three independent PLLs (clocked by HSI , HSE or CSI),
             featuring three different output clocks and able  to work either in integer or Fractional mode.
           (++) A main PLL, PLL1, which is generally used to provide clocks to the CPU
                and to some peripherals.
           (++) Two dedicated PLLs, PLL2 and PLL3, which are used to generate the kernel clock for peripherals.


         (#) CSS (Clock security system), once enabled and if a HSE clock failure occurs
            (HSE used directly or through PLL as System clock source), the System clock
             is automatically switched to HSI and an interrupt is generated if enabled.
             The interrupt is linked to the Cortex-M NMI (Non-Mask-able Interrupt)
             exception vector.

         (#) MCO1 (micro controller clock output), used to output HSI, LSE, HSE, PLL1(PLL1_Q)
             or HSI48 clock (through a configurable pre-scaler) on PA8 pin.

         (#) MCO2 (micro controller clock output), used to output HSE, PLL2(PLL2_P), SYSCLK,
             LSI, CSI, or PLL1(PLL1_P) clock (through a configurable pre-scaler) on PC9 pin.

    [..] System, AHB and APB buses clocks configuration
         (#) Several clock sources can be used to drive the System clock (SYSCLK): CSI,HSI,
             HSE and PLL.
             The AHB clock (HCLK) is derived from System core clock through configurable
             pre-scaler and used to clock the CPU, memory and peripherals mapped
             on AHB and APB bus of the 3 Domains (D1, D2, D3)* through configurable pre-scalers
             and used to clock the peripherals mapped on these buses. You can use
             "HAL_RCC_GetSysClockFreq()" function to retrieve system clock frequency.

         -@- All the peripheral clocks are derived from the System clock (SYSCLK) except those
             with dual clock domain where kernel source clock could be selected through
             RCC_D1CCIPR,RCC_D2CCIP1R,RCC_D2CCIP2R and RCC_D3CCIPR registers.

     (*) : 2 Domains (CD and SRD) for stm32h7a3xx and stm32h7b3xx family lines.

Function Documentation

HAL_StatusTypeDef HAL_RCC_ClockConfig	(	RCC_ClkInitTypeDef *	RCC_ClkInitStruct,
		uint32_t	FLatency
	)

Initializes the CPU, AHB and APB buses clocks according to the specified parameters in the RCC_ClkInitStruct.

Parameters:

RCC_ClkInitStruct,:	pointer to an RCC_OscInitTypeDef structure that contains the configuration information for the RCC peripheral.
FLatency,:	FLASH Latency, this parameter depend on device selected

Note:: The SystemCoreClock CMSIS variable is used to store System Core Clock Frequency and updated by HAL_InitTick() function called within this function; The HSI is used (enabled by hardware) as system clock source after start-up from Reset, wake-up from STOP and STANDBY mode, or in case of failure of the HSE used directly or indirectly as system clock (if the Clock Security System CSS is enabled).; A switch from one clock source to another occurs only if the target clock source is ready (clock stable after start-up delay or PLL locked). If a clock source which is not yet ready is selected, the switch will occur when the clock source will be ready. You can use HAL_RCC_GetClockConfig() function to know which clock is currently used as system clock source.; Depending on the device voltage range, the software has to set correctly D1CPRE[3:0] bits to ensure that Domain1 core clock not exceed the maximum allowed frequency (for more details refer to section above "Initialization/de-initialization functions")

Return values:

None

Definition at line 901 of file stm32h7xx_hal_rcc.c.

HAL_StatusTypeDef HAL_RCC_DeInit ( void )

Resets the RCC clock configuration to the default reset state.

Note:

The default reset state of the clock configuration is given below:

HSI ON and used as system clock source
HSE, PLL1, PLL2 and PLL3 OFF
AHB, APB Bus pre-scaler set to 1.
CSS, MCO1 and MCO2 OFF
All interrupts disabled

This function doesn't modify the configuration of the

Peripheral clocks
LSI, LSE and RTC clocks

Return values:

HAL status

Definition at line 188 of file stm32h7xx_hal_rcc.c.

References __HAL_FLASH_GET_LATENCY, __HAL_FLASH_SET_LATENCY, CLOCKSWITCH_TIMEOUT_VALUE, HAL_GetTick(), HAL_InitTick(), HSE_TIMEOUT_VALUE, HSI_TIMEOUT_VALUE, HSI_VALUE, PLL_TIMEOUT_VALUE, and uwTickPrio.

HAL_StatusTypeDef HAL_RCC_OscConfig ( RCC_OscInitTypeDef * RCC_OscInitStruct )

Initializes the RCC Oscillators according to the specified parameters in the RCC_OscInitTypeDef.

Parameters:

RCC_OscInitStruct,: pointer to an RCC_OscInitTypeDef structure that contains the configuration information for the RCC Oscillators.

Note:: The PLL is not disabled when used as system clock.; Transitions LSE Bypass to LSE On and LSE On to LSE Bypass are not supported by this function. User should request a transition to LSE Off first and then LSE On or LSE Bypass.; Transition HSE Bypass to HSE On and HSE On to HSE Bypass are not supported by this function. User should request a transition to HSE Off first and then HSE On or HSE Bypass.

Return values:

HAL status

Definition at line 405 of file stm32h7xx_hal_rcc.c.

Functions

Detailed Description

Function Documentation