pub type RTCSEL_W<'a> = FieldWriterSafe<'a, u32, BDCR_SPEC, u8, RTCSEL_A, 2, 8>;
Field RTCSEL writer - RTC clock source selection
RTCSEL
No clock
LSE oscillator clock used as RTC clock
LSI oscillator clock used as RTC clock
HSE oscillator clock divided by a prescaler used as RTC clock