The KSZ9897 is a fully integrated layer 2, managed, seven-port gigabit Ethernet switch with numerous advanced features. Five of the seven ports incorporate 10/100/1000 Mbps PHYs. The other two ports have interfaces that can be configured as SGMII, RGMII, MII or RMII. Either of these may connect directly to a host processor or to an external PHY.Full register access is available by SPI or I2C interfaces, and by optional in-band management via any of the data ports. PHY register access is provided by