/* Selects the clock source to output on MCO pin.  */
void RCC_MCOConfig(RCC_MCO_TypeDef mco_src)
/* Selects the clock source to output on MCO pin.  */
void RCC_MCOConfig(RCC_MCO_TypeDef mco_src)
{
    MODIFY_REG(RCC->CFGR, RCC_CFGR_MCO, mco_src);
}