• T S's avatar
    stmhal: Implement delayed RTC initialization with LSI fallback. · 86aa16be
    T S authored
    If RTC is already running at boot then it's left alone.  Otherwise, RTC is
    started at boot but startup function returns straight away.  RTC startup
    is then finished the first time it is used.  Fallback to LSI if LSE fails
    to start in a certain time.
    Also included:
            hold pyb.freq() parameters in RTC backup reg
            option to present datetime sub-seconds in microseconds
            option to enable RTC calibration output
    CLK_LAST_FREQ and RTC_USE_CALOUT are enabled for PYBv1.0.