HAL_RCC_MCOConfig() function

specifies the output direction for the clock source. This parameter can be one of the following values: @arg RCC_MCO1: Clock source to output on MCO1 pin(PA8). @arg RCC_MCO2: Clock source to output on MCO2 pin(PC9).

specifies the clock source to output. This parameter can be one of the following values: @arg RCC_MCO1SOURCE_HSI: HSI clock selected as MCO1 source @arg RCC_MCO1SOURCE_LSE: LSE clock selected as MCO1 source @arg RCC_MCO1SOURCE_HSE: HSE clock selected as MCO1 source @arg RCC_MCO1SOURCE_PLLCLK: main PLL clock selected as MCO1 source @arg RCC_MCO2SOURCE_SYSCLK: System clock (SYSCLK) selected as MCO2 source @arg RCC_MCO2SOURCE_PLLI2SCLK: PLLI2S clock selected as MCO2 source, available for all STM32F4 devices except STM32F410xx @arg RCC_MCO2SOURCE_I2SCLK: I2SCLK clock selected as MCO2 source, available only for STM32F410Rx devices @arg RCC_MCO2SOURCE_HSE: HSE clock selected as MCO2 source @arg RCC_MCO2SOURCE_PLLCLK: main PLL clock selected as MCO2 source

specifies the MCOx prescaler. This parameter can be one of the following values: @arg RCC_MCODIV_1: no division applied to MCOx clock @arg RCC_MCODIV_2: division by 2 applied to MCOx clock @arg RCC_MCODIV_3: division by 3 applied to MCOx clock @arg RCC_MCODIV_4: division by 4 applied to MCOx clock @arg RCC_MCODIV_5: division by 5 applied to MCOx clock