IEEE 802.3cm-2020 pdf download

IEEE 802.3cm-2020 pdf download.IEEE Standard for Ethernet Amendment 7:Physical Layer and Management Parameters for 400 Gb/s over Multimode Fiber.
(‘hange 138.2 as follows:
This subclause specifies the services provided by the 5OGBASE-SR, 1OOGBASE-SR2 and 200GI3ASE-SR4. and 400GBASE-SR8 PMDs. The service interfaces for these PMDs arc described in an abstract manner and do not imply any particular implementation. The PMD service interface supports the exchange of encoded data between the PMA entity that resides just above the PMD, and the PMD entity. The PMD translates the encoded data to and from signals suitable for the specified medium.
The 5OGBASE-SR PMD service interface is an instance of the inter-sublayer service interface defined in 131.3, with a single symbol stream (n = 1).
The 100GBASE-SR2 PMD service interface is an instance of the inter-sublayer service interface defined in 116.3, with two parallel symbol streams (n 2).
The 200GBASE-SR4 PMD service interface is an instance of the inter-sublayer service interface defined in 1 16.3, with four parallel symbol streams (n = 4).
The 400GBASE-SR8 PMD service interface is an instance of the inter-sublayer service interface defined in 116.3. with eight parallel symbol streams (n = 8).
The service interface primitives are summarized as follows:
PMD:IS_UNITDATA_i.requcst
PMD:IS_UNITDATA_i. indication
PMD:IS SIGNAL.indication
The 5OGBASE-SR PMD has a single symbol stream, hence i = 0.
The 1 OOGBASE-SR2 PMD has two parallel symbol streams, hence i = 0 to 1.
The 200GBASE-SR4 PMD has four parallel symbol streams, hence i 0 to 3.
The 400GBASE-SR8 PMD has eight parallel symbol streams, hence i 0 to 7.
In the transmit direction, the PMA continuously sends n streams of PAM4 symbols to the PMD, one per lane, using the PMD:IS_UNITDATA_i.request primitive, at a nominal signaling rate of 26.5625 GBd. The PMD converts these streams of symbols into appropriate signals on the MDI.
In the receive direction, the PMD continuously sends ii streams of PAM4 symbols to the PMA, corresponding to the signals received from the MDI. one per lane, using the PMD:IS_UNITDATA_Lindication primitive, at a nominal signaling rate of 26.5625 GBd.
The SIGNAL_OK parameter of the PMD:IS_SIGNAL.indication primitive corresponds to the variable SIGNAL_DETECT parameter as defined in 138.5.4. The SIGNAL_DETECT parameter can take on one of two values: OK or FAIL. When SIGNAL_DETECT FAIL, the rx_symbol parameters are undefined.
NOTE—SIGNAL DETECT OK does not guarantee that the rx_syrnbol parameters are known to be good. It is possible for a poor quality link to provide sufficient light for a SIGNAL_DETECT — OK indication and still not meet the HER defined in 138.1.1.
138.3 Delay and Skew
138.3.1 Delay constraints
Change 138.3.1 asfidlows:
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 5OGBASE-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 IOOGBASE-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-5R4 PMD including 2 rn of fiber in one direction shall be no more than 4096 bit times (8 pause_quanta or 20.48 ns).
The sum of the transmit and receive delays at one end of the link contributed by the 400GBASE-SRX PMD including 2 m of fiber in one direction shall be no more than 8192 hit times (16 pause quanta or 20.48 ns).
Descriptions of overall system delay constraints and the definitions for bit times and pause_quanta, can be found in 131.4 for 5OGBASE-SR, in 80.4 for IOOGBASE-5R2, and in 116.4 and its references tbr 200GBASE-5R4 and 400GBASE-SR8.
138.3.2 Skew Constraints
Change the title of 138.3.2.2 as follows:
138.3.2.2 Skew Constraints for IOOGBASE-5R2, and 200GBASE-5R4. and 400GBASE-SR8
138.4 PMD MDIO function mapping
Change Table 138—4 and Table 138—5 as follows.