EFM8LB1 Datasheet, PDF (67/70 Pages) Silicon Laboratories – The EFM8LB1 device family are fully integrated, mixed-signal system-on-a-chip MCUs. Highlighted features are listed below

11. Revision History
11.1 Revision 0.1
Initial release.
11.3 Revision 0.4
Updated specification tables based on current device characterization status and production test limits.
Added bootloader section.
Added typical connection diagrams.
Corrected CLU connections in pin function tables.
EFM8LB1 Data Sheet
Revision History
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Preliminary Rev. 0.4 | 66