1 of 19September 18, 2007Document Number EDCS-540123 Revision Revision 1.2QSGMII SpecificationThe Quad Serial Gigabit Media Independent Interface (QSGMII) is designed to satisfy the following requirements:•Convey 4 ports of network data and port speed between a 10/100/1000 PHY and a MAC with significantly less signal pins than required for GMII & SGMII.•Operate in both half and full duplex and at all port speeds.•This implementation can be extended to other port to channel ratios. However, this is outside the scope of this document.QSGMII Specification: EDCS-540123Revision 1.22 of 19September 18, 2007Change HistoryDefinitionsMII – Media Independent Interface: A digital interface that provides a 4-bit wide datapath between a 10/100 Mbit/s PHY and a MAC sublayer. Since MII is a subset of GMII, in this document, we will use the term “GMII” to cover all of the specification regarding the MII interface.GMII – Gigabit Media Independent Interface: A digital interface that provides an 8-bit wide datapath between a 1000 Mbit/s PHY and a MAC sublayer. It also supports the 4-bit wide MII interface as defined in the IEEE 802.3z specification. In this document, the term “GMII” covers all 10/100/1000 Mbit/s interface operations.SGMII – Serial Gigabit Media Independent Interface: A digital interface that provides a 1.25 Gbps serial dual-data-rate datapath between a 1000 Mbit/s PHY and a MAC sublayer. Refer to ENG-46158 or ftp://ftp-eng.cisco.com/smii/smii.html for details.RevisionDateDescriptionAuthor1.2Spetember 7,2007Updated Bit[13] and Bit[0] on Table3 and added a statement of possible removal of the first byte of frame in 10/100Mbit/s operation to match SGMII spec.Akin Koyuncuoglu1.1June 20, 2007Reword Note1, Added a...