/* Enables or disables the Low Speed APB (APB1) peripheral clock.  */
void RCC_APB1PeriphClockCmd(u32 apb1_periph, FunctionalState state)
/* Enables or disables the Low Speed APB (APB1) peripheral clock.  */
void RCC_APB1PeriphClockCmd(u32 apb1_periph, FunctionalState state)
{
    (state) ? (RCC->APB1ENR |= apb1_periph) : (RCC->APB1ENR &= ~apb1_periph);
}