HAL RCC control functions migration

This section provides information about the HAL RCC control functions migration.

In HAL2, the change is only a renaming of this functions. These functions return the value of frequency in Hz for the system clock.

HAL RCC get system clock frequency

Function Description

The HAL_RCC_GetSysClockFreq function returns the system clock frequency.

HAL1

HAL2

Function name

HAL_RCC_GetSysClockFreq

HAL_RCC_GetSYSCLKFreq

Return Values

System clock frequency in Hz

System clock frequency in Hz

Example Usage

HAL1

HAL2 

uint32_t sysclk_freq;
sysclk_freq = HAL_RCC_GetSysClockFreq();

uint32_t sysclk_freq;
sysclk_freq = HAL_RCC_GetSYSCLKFreq();

HAL RCC get PCLK2 frequency

Function Description

The HAL_RCC_GetPCLK2Freq function returns the PCLK2 frequency.

HAL1

HAL2

Function name

HAL_RCC_GetPCLK2Freq

HAL_RCC_GetPCLK2Freq

Return Values

PCLK2 frequency in Hz

PCLK2 frequency in Hz

HAL RCC get HCLK frequency

Function Description

The HAL_RCC_GetHCLKFreq function returns the HCLK frequency.

HAL1

HAL2

Function name

HAL_RCC_GetHCLKFreq

HAL_RCC_GetHCLKFreq

Return Values

HCLK frequency in Hz

HCLK frequency in Hz

HAL RCC get PCLK1 frequency

Function Description

The HAL_RCC_GetPCLK1Freq function returns the PCLK1 frequency.

HAL1

HAL2

Function name

HAL_RCC_GetPCLK1Freq

HAL_RCC_GetPCLK1Freq

Return Values

PCLK1 frequency in Hz

PCLK1 frequency in Hz

HAL RCC get PCLK3 frequency

Function Description

The HAL_RCC_GetPCLK3Freq function returns the PCLK3 frequency.

HAL1

HAL2

Function name

HAL_RCC_GetPCLK3Freq

HAL_RCC_GetPCLK3Freq

Return Values

PCLK3 frequency in Hz

PCLK3 frequency in Hz

In HAL1, one API manages all peripheral clock sources. In HAL2, this API is removed, and unitary APIs are provided to select the kernel clock source for each peripheral.

HAL RCCEx peripheral clock configuration

Function Description

The HAL_RCCEx_PeriphCLKConfig function configures the peripheral clock sources.

HAL1

HAL2

Function name

HAL_StatusTypeDef HAL_RCCEx_PeriphCLKConfig(const RCC_PeriphCLKInitTypeDef *pPeriphClkInit);

Function split into multiple unitary APIs:

  • HAL_RCC_USART1_SetKernelClkSource()

  • HAL_RCC_LPUART1_SetKernelClkSource()

  • HAL_RCC_I2C1_SetKernelClkSource()

  • HAL_RCC_LPTIM1_SetKernelClkSource()

  • …

Example Usage

HAL1

HAL2 

RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;

PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART1;
PeriphClkInitStruct.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);

hal_status_t status;

status = HAL_RCC_USART1_SetKernelClkSource(HAL_RCC_USART1_CLKSOURCE_PCLK2);

HAL RCCEx get peripheral clock configuration

Function Description

In HAL1, one API retrieves all peripheral clock sources. In HAL2, this API is removed, and unitary APIs are provided to get the kernel clock source for each peripheral.

HAL1

HAL2

Function name

void HAL_RCCEx_GetPeriphCLKConfig(RCC_PeriphCLKInitTypeDef *pPeriphClkInit);

Function split into multiple unitary APIs:

  • HAL_RCC_USART1_GetKernelClkSource()

  • HAL_RCC_ICLK_GetKernelClkSource()

  • HAL_RCC_SDMMC_GetKernelClkSource()

  • HAL_RCC_ADCDAC_GetKernelClkSource()

  • HAL_RCC_DAC1_GetSampleHoldClkSource()

  • HAL_RCC_SPI3_GetKernelClkSource()

  • HAL_RCC_RTC_GetKernelClkSource()

  • HAL_RCC_LTDC_GetKernelClkSource()

  • …

Example Usage

HAL1

HAL2 

RCC_PeriphCLKInitTypeDef PeriphClkInitStruct;

HAL_RCCEx_GetPeriphCLKConfig(&PeriphClkInitStruct);

hal_rcc_usart1_clk_src_t usart1_clk_src;

usart1_clk_src = HAL_RCC_USART1_GetKernelClkSource();

HAL RCCEx get peripheral clock frequency

Function Description

In HAL2, the peripheral clock frequency can be retrieved using two methods: unitary APIs for each peripheral instance or global APIs for peripherals.

HAL1

HAL2

Function name

uint32_t HAL_RCCEx_GetPeriphCLKFreq(uint64_t PeriphClk);

Function split into multiple unitary APIs:

  • HAL_RCC_RTC_GetKernelClkFreq()

  • HAL_RCC_I2C_GetKernelClkFreq()

  • HAL_RCC_I2C1_GetKernelClkFreq();

  • HAL_RCC_I2C2_GetKernelClkFreq();

  • HAL_RCC_I2C3_GetKernelClkFreq();

  • HAL_RCC_I2C4_GetKernelClkFreq();

  • HAL_RCC_I2C5_GetKernelClkFreq();

  • HAL_RCC_I2C6_GetKernelClkFreq();

  • …

Example Usage

HAL1

HAL2 

uint32_t periph_clk_freq;

periph_clk_freq = HAL_RCCEx_GetPeriphCLKFreq(RCC_PERIPHCLK_USART1);

uint32_t usart1_clk_freq;

usart1_clk_freq = HAL_RCC_USART1_GetKernelClkFreq();