RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);// Enable PWR clockPWR_RTCAccessCmd(ENABLE);// Enable access to RTC// Note: the LSI is used as RTC source clock// The RTC Clock may vary due to LSI frequency dispersion.RCC_LSICmd(ENABLE);// Enable LSIwhile(RCC_GetFlagStatus(RCC_...