rtc_write(CMOS_STATUS_A, 0x26); // 32,768Khz src, 976.5625us updates
rtc_mask(CMOS_STATUS_B, ~RTC_B_DSE, RTC_B_24HR);
rtc_read(CMOS_STATUS_C);
rtc_write(CMOS_STATUS_A, 0x26); // 32,768Khz src, 976.5625us updates
rtc_mask(CMOS_STATUS_B, ~RTC_B_DSE, RTC_B_24HR);
rtc_read(CMOS_STATUS_C);