IEEE 802.3cm-2020 pdf free download – Amendment 7: Physical Layer and Management Parameters for 400 Gb/s over Multimode Fiber.
138.2 Physical Medium Dependent (PMD) service interface
Change 1)1.2 as follows:
This subclause specifies the services provided by the 5OGBASE-SR, I000BASE-SR2,-stttd 200GBASE-SR4, and 400GBASE-SRS PMDs The service interfaces fin these PMDs are described in an abstract niannet and do not imply any particular implementation. The PMD sen ice interface supports the exchange of encoded data between the PMA entity that resides just above the P5(0. and the PMD entity. 11w PMD translates Else encoded data to and front signals suitable for the specified medium.
The 5OGRASE-SR P510 serviee interface is an instance of the inter-sublaver service interface defined in I Ll,withasinglcsy,nbolstreant ln I).
The IUOGIIASE-SR2 PMI) service interface is an instance of the inter-sublayer sen ice interfaee defined in II *3, with two parallel symbol stteams (n a 2 [
The 200GHASE-SR4 P5(f) sen ice interface is an instance of the incer-sublayer sen ice inrerfaee defined in II ‘ , with four parallel symbol streams In — The 400GBASE-SRS PMD sen ieeintet face wan instance of the inter-sublayetsen ice interface defined in
II ti.3y,’itlt eight parallel symbol stieanssjn —zI).
The sen ice interface primitives are suntmari.red as follows:
P5(0.15 L1NITDATA i.request
PMD.lSLINITOATALindication
P5(0.15 SIGNAL.indieanon
The 500HASE-SR PhIl) has a single symbol streant, hence 1 0.
The I006BASE-SR2 P510 has two parallel symbol streams. bcncei — (I to I.
11w 200GHASE-SR4 P510 has four pat allel symbol streams, hence, = 0 to).
The 400GHASE-SRl( P510 has eight parallel symbol streams, hence L’ (I tot
In the transntit direction, the PMA continuously sends,, streams of PAM4 symbols to the PM!), one per lane, using the PMD:IS UNITDATA i.requesl primitive. ata nontinal signaling rate of 26.5625 (‘iRd. The PMI) converts these streams of syntbols into appropriate signals on the MDI.
In the receive direction, the P5(0 continuously sends n streams of PAM4 symboLs to the PMA. corresponding to the signals received front the MDI. one per lane, using the PMD.IS ITNITOATA i.indieation primitive, at a nominal signaling rate of 26.5625 GBLI.
11w SIGNAL OK parameter of the PMD:IS SlGNALindication primitive corresponds to the variable SIGNAL DETECT parameter as defined in I 311.5.4. The SIGNAL DETECT parameter can take on one of two values: OK ot FAIL. When SIGNAL DETECT FAIL, the ra symbol paranwters are undefined.
NOTE—SIGNAL DETECT – OK does nor guarantee that the cx symbol paratneters are known to be goon It is pcnnible for a poor quality link to provide sufficient light for a SIGNAl. DETECT — OK indication and still not mcci the I4IER defincd in I 311.1
138.3 Delay and Skew
138.3.1 Delay constraints
Change 138.3.1 as follows:
An upper bound to the delay through the PMA and PMD is required for predictable operation of the MAC Control PAUSE operation.
The sum of the transmit and receive delays at one end of the link contributed by the 50GBASE-SR PMD including 2 m of fiber in one direction shall be no more than 1024 bit times (2 pause_ quanta or 20.48 ns).
The sum of the transmit and receive delays at one end of the link contributed by the 100GBASE-SR2 PMD including 2 m of fiber in one direction shall be no more than 2048 bit times (4 pause_ quanta or 20.48 ns).
The sum of the transmit and receive delays at one end of the link contributed by the 200GBASE- SR4 PMD including 2 m of fiber in one direction shall be no more than 4096 bit times (8 pause_ _quanta or 20.48 ns).IEEE 802.3cm pdf download.