A simple breakout board for the EFM8BB21F16 (QFN-20) MCU
The silkscreen might be misleading, clarification below the picture:
The bottom row (starting with Vin) ends with 0.2, 0.1, 0.0, Gnd to the right. The 4-pin connector located towards the center of the board has 3V3, RSTb (C2CK), 2.0 (C2D), Gnd from left to right.