The Realtek RTL8214QF is used to convert QSGMII Serdes interfaces to four 1000Base-X/100FX ports. IEEE802.3 Clause 22 MIIM formats are supported thus Switch controller can access the related register to get status and configure them.
5Gbps QSGMII to x4 1Gbps 100FX/1000Base-X conversion
5Gbps QSGMII to x4 SGMII conversion.
QSGMII Phyceiver for four 100Base-FX/1000Base-X/SGMII