LL RCC Macros

Common Write and read registers Macros

STM32C562xx STM32C5A3xx STM32C542xx

group RCC_LL_EM_WRITE_READ

Defines

LL_RCC_WRITE_REG ( reg , value ) STM32_WRITE_REG(RCC->reg, (value))

Write a value in RCC register.

Parameters :

• reg – Register to be written

• value – Value to be written in the register

LL_RCC_READ_REG ( reg ) STM32_READ_REG(RCC->reg)

Read a value in RCC register.

Parameters :

• reg – Register to be read

Return values :

Register – value

Calculate frequencies

STM32C562xx STM32C5A3xx STM32C542xx

group RCC_LL_EM_CALC_FREQ

Defines

LL_RCC_CALC_HCLK_FREQ ( sysclk_freq , ahb_prescaler )

((sysclk_freq) >> \

AHBPrescTable[((ahb_prescaler)& RCC_CFGR2_HPRE) \

>> RCC_CFGR2_HPRE_Pos])

Helper macro to calculate the HCLK frequency.

Parameters :

• sysclk_freq – SYSCLK frequency (based on HSIS/HSIDIV3/HSE/PSIS)

• ahb_prescaler – This parameter can be one of the following values:

  • LL_RCC_HCLK_PRESCALER_1

  • LL_RCC_HCLK_PRESCALER_2

  • LL_RCC_HCLK_PRESCALER_4

  • LL_RCC_HCLK_PRESCALER_8

  • LL_RCC_HCLK_PRESCALER_16

  • LL_RCC_HCLK_PRESCALER_64

  • LL_RCC_HCLK_PRESCALER_128

  • LL_RCC_HCLK_PRESCALER_256

  • LL_RCC_HCLK_PRESCALER_512

Return values :

HCLK – clock frequency (in Hz)

LL_RCC_CALC_PCLK1_FREQ ( hclk_freq , apb1_prescaler )

((hclk_freq) >> \

(APBPrescTable[((apb1_prescaler)& \

RCC_CFGR2_PPRE1) >> RCC_CFGR2_PPRE1_Pos]))

Helper macro to calculate the PCLK1 frequency (ABP1).

Parameters :

• hclk_freq – HCLK frequency

• apb1_prescaler – This parameter can be one of the following values:

  • LL_RCC_APB1_PRESCALER_1

  • LL_RCC_APB1_PRESCALER_2

  • LL_RCC_APB1_PRESCALER_4

  • LL_RCC_APB1_PRESCALER_8

  • LL_RCC_APB1_PRESCALER_16

Return values :

PCLK1 – clock frequency (in Hz)

LL_RCC_CALC_PCLK2_FREQ ( hclk_freq , apb2_prescaler )

((hclk_freq) >> \

(APBPrescTable[((apb2_prescaler)& \

RCC_CFGR2_PPRE2) >> RCC_CFGR2_PPRE2_Pos]))

Helper macro to calculate the PCLK2 frequency (ABP2).

Parameters :

• hclk_freq – HCLK frequency

• apb2_prescaler – This parameter can be one of the following values:

  • LL_RCC_APB2_PRESCALER_1

  • LL_RCC_APB2_PRESCALER_2

  • LL_RCC_APB2_PRESCALER_4

  • LL_RCC_APB2_PRESCALER_8

  • LL_RCC_APB2_PRESCALER_16

Return values :

PCLK2 – clock frequency (in Hz)

LL_RCC_CALC_PCLK3_FREQ ( hclk_freq , apb3_prescaler )

((hclk_freq) >> \

(APBPrescTable[((apb3_prescaler)& \

RCC_CFGR2_PPRE3) >> RCC_CFGR2_PPRE3_Pos]))

Helper macro to calculate the PCLK3 frequency (ABP3).

Parameters :

• hclk_freq – HCLK frequency

• apb3_prescaler – This parameter can be one of the following values:

  • LL_RCC_APB3_PRESCALER_1

  • LL_RCC_APB3_PRESCALER_2

  • LL_RCC_APB3_PRESCALER_4

  • LL_RCC_APB3_PRESCALER_8

  • LL_RCC_APB3_PRESCALER_16

Return values :

PCLK3 – clock frequency (in Hz)