Copy of presentation given to IEEE 802.3z September 1996 Interim Meeting in Coeur d'Alene, Idaho. ARCHITECTURAL OVERVIEW (A PROPOSAL) __________________________ > Overall Block Diagram > Details (for 8B10B) > Outline of Standard Prepared for 3Com Corporation by Dr. Howard Johnson howiej@sigcon.com U.S. (206) 556 0800 tel. September 4, 1996 Thanks to SUN and many others for their support in developing this proposal This is a proposal for the architectural naming and organization of the various pieces of our standard. > It follows the established conventions of 802.3 (as best I could manage) > It follows the outline presented in Enschede by Mr. Frazier > It adds details as needed to (hopefully) glue together all the pieces. Overview from 100BASE-T __________________________ (see figure 4-1, page 20, in 802.3u Fast Ethernet) Here's what we had in Fast Ethernet. Note that the level of detail contained in this picture is not too great. Note that while the MII may or may not be present in an actual implementation, it is always in the drawing. Note that some other commonly used interfaces, which are almost always present in implementations, do not appear in the drawing. The 100BASE-X PMD service interface comes to mind (the serial connection to the optics) This is not an implementation picture, it's a picture that explains how the standard is organized. We should follow suite. 1000 Mb/s Block Diagram __________________________ Looks like previous slide, with a big note about the MII, which is now called the GMII. GMII (Gigabit Medium Independant Interface logical definition). - Can use 8B10B PMA service interface electrical specification - Not yet known if this will be detachable Here's a suggestion for how our layers could connect (sorry, figure doesn't traslate to ASCII, but it looks like fig. 4-1 from 802.3u). MAC is the MAC PCS does data coding PMA and PMD do analog stuff For 8B10B, PMA is basically an ANSI Fibre-channel 10- bit SERDES chip The GMII is shown. The PMA service interface (ANSI Fibre-channel 10-bit SERDES interface) is not. Next I'll show, for 8B10B-coded devices, what goes in each of the bottom layers. Later in the day, Mr. Grow will present some ideas on how to implement the GMII in a way that would work for 8B10B-coded stuff, and also for a horizontal copper PHY , or any other future PHY development. PCS Layer for 8B10B __________________________ We still need transmit and receive state machines, like 100BASE-X. I show the 8B10B coder present in this layer. > The GMII is shown as an 8-bit + control interface > The SERDES interface is shown at the bottom. Neat feature! The GMII and PMA service interface will be designed to use the same physical spec; that means that a chip manufacturer can multiplex both interfaces to the same pins. The chip can then be run in a mode with GMII, or with SERDES interface. PMA Layer for 8B10B __________________________ This layer is a big serializer. It's also responsible for establishing 10-bit code-word sync (each data octet is coded as a 10-bit code word). I think most of the people working in this area feel it's a good idea to just use the same interface definitions here that are used in ANSI for the 10-bit serializer. PMD Layer for 8B10B Optics __________________________ At the moment, we seem to be looking at three different 8B10B-coded PMD sublayers: > Shortwave laser optics > Longwave laser optics > Short copper jumpers, for switchroom and closet applications, maybe 20m long. The interface suggested here to the PMD is differential serial PECL. Outline of Standard __________________________ 06 PLS Service Interface (existing clause 6) 34 Reconciliation sublayer and GMII 35 8B10B PCS and PMA layers 36 PMD: SWL optics 37 PMD: LWL optics 38 PMD: Copper jumpers 39 UTP PHY (all layers) 40 Repeater for 1000 Mb/s baseband networks 41 System considerations for multi-segment 1000 Mb/s networks * Plus change pages to base standard, as necessary e.g. clauses 1, 4, 28, and 30 06 PLS Service Interface (existing clause 6) __________________________ > Use as is, with amendments for o Full-duplex, and with o Possible extension to provide carrier_extend indication 34 Reconciliation sublayer and GMII __________________________ o Analogous to 100BASE-T clause 22 but without electrical/physical definitions o Defines a common logical service interface that must be supported by all gigabit PCS devices o Maps the PLS service primitives to logical signals like TXD, TX_EN, TX_ER, RXD, RX_DV, and RX_ER (see figure 22-3 in 802.3u) The GMII can be conveyed using the same electrical definitions defined in the 8B10B PMA service interface (with appropriate pin mappings) - that means you can easily make one chip that implements either the GMII or the 8B10B PMA service interface (= 10-bit SERDES interface). 35 8B10B PCS and PMA layers __________________________ o 8B10B PCS sublayer o Analogous to the PCS layer in 100BASE-X (clause 24) o Contains 8B10B coder for use with optical or short copper links o 8B10B PMA service interface o Similar to FC 10-bit serializer interface (scaled up to 1.25 Gbaud) o 10-bits parallel, at 125 MHz o 8B10B PMA sublayer o Similar to ANSI 10-bit SERDES chip o Used for all 8B10B-coded physical interface types o 8B10B PMD service interface o Probably serial PECL o Used for all 8B10B-coded physical interface types 36 PMD: SWL optics __________________________ o Used with 8B10B PMA o Wavelength range of 770-860 nm o Works on 50 or 62.5 um MMF o Include specification of fiber types o Include specification of media connector 37 PMD: LWL optics __________________________ o Used with 8B10B PMA o Wavelength range of 1270-1355 nm o Works on SMF o Also works on 50 or 62.5 um MMF o Include specification of fiber types (includes repetition of same MMF parameters as used for SWL) o Include specification of media connector 38 PMD: Copper jumpers __________________________ o Used with 8B10B PMA o Include specification of media and media connector 39 UTP PHY (all layers) __________________________ Let's reserve a place for horizontal copper. When done, it will go into clause 39. o Includes PCS sublayer appropriate for horizontal copper o Includes other sublayers as needed NOTE: For 8B10B links, we have three PMD's that all use the same PCS/PMA sublayer stack. The three PMD's each therefore have their own clause number. The UTP PHY is less configurable. It will be written in one clause, like 100BASE- T2 or 100BASE-T4. FOR MORE INFORMATION... __________________________ See Thatcher, Hanson, Swirhun proposal for contents of 8B10B optical PMD's See Johnson, Taborek et. al, proposal for contents of 8B10B PCS layer