Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Keil/AT32F413xx_v2/RTC/CTRLL#0x0
RTC Control Register Low
Time second flag
Time alarm flag
Overflow Flag
RTC update finish
RTC configuration enable
RTC configuration finish
https://github.com/cmsis-svd/cmsis-svd-data