8101 Datasheet, PDF (57/172 Pages) LSI Computer Systems – Gigabit Ethernet Controller

2.15 AutoNegotiation
The AutoNegotiation algorithm is a negotiation sequence between two
stations over the 10-bit PHY interface that establishes a good link
between two stations, and configures both stations for the same mode of
operation. The AutoNegotiation algorithm in the controller meets all
specifications defined in IEEE 802.3z.
AutoNegotiation uses a stream of /C/ ordered sets to pass an
AutoNegotiation data word to and from a remote station. The /C/ ordered
set stream consists of an alternating sequence of /C1/ and /C2/ ordered
sets. The /C1/ and /C2/ ordered sets contain two unique 10B code words
plus a 16-bit AutoNegotiation data word, as defined in IEEE 802.3z and
shown in Figure 2.6.
Figure 2.6 AutoNegotiation Data Format
C2
K28.5
D21.5
C1
<Bits[0:7]>
<Bits[8:15]>
K28.5
D2.2
C2
<Bits[0:7]>
<Bits[8:15]>
From
Registers
21 – 22
From
Registers
21 – 22
C1
ABCDEFGH
abcdefghij
TX[0]
RX[0]
TX[9]
RX[9]
PCS 8B Codes
PCS 10B Codes
TX PHY. INT.
RX PHY. INT.
Note:
< > Means 10B Encoded
AutoNegotiation
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