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[802.3ae] Clause 49, Receive State Machine





Hi Pat,

Definition of R_BLOCK_TYPE in page 366, clause 49 as:

Values: C; The vector contains s sync header of 10 and one of the following:
           a) A block type field of 0x1e and eight valid control characters
other than /E/;
           b) A block type field of 0x2d or 0x4b, a valid O code, and four
valid control characters;
           c).....

         ............
        T; The vector contains a sync header of 10, a block type field of
0x87, 0x99, 0xaa, 0xb4, 0xcc, 0xd2, 0xe1 or 0xff and all control characters
are valid.

 When a 64b/66b data stream contains the End Of Packet frame followed by
Error frames as:

                           0xaa D0 D1 "00000"  0x00  0x1e  0x1e  0x1e  0x1e
(T frame with four /E/s)
                           0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e
(Error frame)
                           0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e 0x1e
(Error frame)


Based on the C definition, and on the Receive state machine flow, Receive
state machine should stuck in the RX_T until a C block frame, or a S block
frame is received.  However, from the flow presentation of the Receive state
machine, it looks like the intention of the RX_T state is only transitional,
meaning that RX_T duration is only one clock at a time.  Can you clarify
this?

Regards,

Tuan