ʾʹõԴ
RTC_OUT      --   PC13


ʾḶ́
1ϵϵͳʱΪ48MHzPLL
2ʼRTCRTCʱԴΪLXTALģʽRTC_OUTźţPC13
3ֶVBATģʽʱRTC_OUT1256Hz