RTC_STATUSA
rtcout_locked(RTC_STATUSA, rtc_statusa);
writertc(RTC_STATUSA, rtc_statusa);
rtcin_locked(RTC_STATUSA); /* dummy to get rtc_reg set */
rtcout_locked(RTC_STATUSA, rtc_statusa);
while (rtcin(RTC_STATUSA) & RTCSA_TUP)