EFM8UB2 Datasheet, PDF (47/50 Pages) Silicon Laboratories – The EFM8UB2 highlighted features are listed below

10. Revision History
EFM8UB2 Data Sheet
Revision History
10.1 Revision 1.2
Updated the VDD Ramp Time specification in Table 4.3 Reset and Supply Monitor on page 10 to a maximum of 1 ms.
10.2 Revision 1.1
Initial release.
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Rev. 1.2 | 46