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GD32L23x User Manual
257
16.
Real time clock (RTC)
16.1.
Overview
The RTC provides a time which includes hour/minute/second/sub-second and a calendar
includes year/month/day/week day. The time and calendar are expressed in BCD code except
sub-second. Sub-second is expressed in binary code. Hour adjust for daylight saving time.
Working in power saving mode and smart wakeup is software configurable. Support improving
the calendar accuracy using extern accurate low frequency clock.
16.2.
Characteristics
Daylight saving compensation supported by software
External high-accurate low frequency(50Hz or 60Hz) clock used to achieve higher
calendar accuracy performed by reference clock detection option function
Atomic clock adjust(max adjust accuracy is 0.95PPM) for calendar calibration performed
by digital calibration function
Sub-second adjustment by shift function
Time-stamp function for saving event time
Three Tamper sources can be chosen and tamper type is configurable
Programmable calendar and two field maskable alarms
Maskable interrupt source:
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Alarm 0 and Alarm 1
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Time-stamp detection
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Tamper detection
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Auto wakeup event
Five 32-bit (20 bytes total) universal backup registers which can keep data under power
saving mode. Backup register will be reset if tamper event detected