GD32W51x User Manual
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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
Two 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
Twenty 32-bit (80 bytes total) universal backup registers which can keep data under
power saving mode. Backup register will be reset if tamper event detected
Support TrustZone security protection
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RTC global securable
-
The TZEN option bit is used to enable trustzone in the device. When TZEN = 1,
trustzone is enable. When TZEN = 0, TrustZone is disabled, and at this time, the
APB access to the RTC registers are non-secure.
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Alarm 0, Alarm 1, wake-up Timer and timestamp can be independently configured
as secure or non-secure
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Tamper secure or non-secure configuration.
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Configure the backup domain registers in three configurable-size areas.There are
read/write secure area,
write secure/read non-secure area and read/write non-
secure area.