Assuming "KSZ80 OB S4LV02" is a KSZ8081, here are the definitive specifications you would find in the datasheet:
The most common footprint utilizing this marking code features a 24-pin QFN layout optimized for RMII routing. : Differential transmit outputs. RXP / RXM (Pins 4, 5) : Differential receive inputs. REFOUT (Pin 8) : 50MHz reference clock output for RMII mode. ksz80 ob s4lv02 datasheet
KSZ9031RNX - Gigabit Ethernet Transceiver with RGMII Support Assuming "KSZ80 OB S4LV02" is a KSZ8081, here