Samsung S5PC100 User Manual page 614

S5PC100 USER'S MANUAL (REV1.0) REAL TIME CLOCK
6 BACKUP BATTERY OPERATION
The RTC logic can be driven by the backup battery, which supplies the power through the RTCVDD pin into the
RTC block, even if the system power is off. If the system is off, the interfaces of the CPU and RTC logic should be
blocked, and the backup battery only drives the oscillation circuit and the BCD counters to minimize power
dissipation.
7 ALARM FUNCTION
The RTC generates an alarm signal at a specified time in the power-off mode or normal operation mode. In
normal operation mode, the alarm interrupt (ALMINT) is activated. In the power-off mode, the power management
wakeup (PMWKUP) signal is activated as well as the ALMINT. The RTC alarm register (RTCALM) determines the
alarm enable/ disable status and the condition of the alarm time setting.
7.4-3