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Cortina Systems LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
4.9 100 Mbps Operation
4.9.3.1
Link
In 100 Mbps mode, the LXT9785/LXT9785E establishes a link whenever the descrambler
becomes locked and remains locked for approximately 50 ms. Whenever the descrambler
loses lock (<16 consecutive idle symbols during a 2 ms window), the link is taken down.
This provides a robust link, filtering out any small noise hits that may otherwise disrupt the
link. Furthermore, 100 Mbps idle patterns will not bring up a 10 Mbps link.
0 1 1 0
6
0 1 1 1 0
Data 6
DATA
0 1 1 1
7
0 1 1 1 1
Data 7
1 0 0 0
8
1 0 0 1 0
Data 8
1 0 0 1
9
1 0 0 1 1
Data 9
1 0 1 0
A
1 0 1 1 0
Data A
1 0 1 1
B
1 0 1 1 1
Data B
1 1 0 0
C
1 1 0 1 0
Data C
1 1 0 1
D
1 1 0 1 1
Data D
1 1 1 0
E
1 1 1 0 0
Data E
1 1 1 1
F
1 1 1 0 1
Data F
IDLE
undefined
I 1
1 1 1 11
Idle. Used as inter stream fill code.
0 1 0 1
J 2
1 1 0 0 0
Start-of-Stream Delimiter (SSD),
part 1 of 2.
CONTROL
0 1 0 1
K 2
1 0 0 0 1
Start-of-Stream Delimiter (SSD),
part 2 of 2.
undefined
T 3
0 1 1 0 1
End-of-Stream Delimiter (ESD),
part 1 of 2.
undefined
R 3
0 0 1 1 1
End-of-Stream Delimiter (ESD),
part 2 of 2.
undefined
H 4
0 0 1 0 0
Transmit Error. Used to force
signaling errors.
undefined
Invalid
0 0 0 0 0
Invalid
undefined
Invalid
0 0 0 0 1
Invalid
undefined
Invalid
0 0 0 1 0
Invalid
INVALID
undefined
Invalid
0 0 0 1 1
Invalid
undefined
Invalid
0 0 1 0 1
Invalid
undefined
Invalid
0 0 1 1 0
Invalid
undefined
Invalid
0 1 0 0 0
Invalid
undefined
Invalid
0 1 1 0 0
Invalid
undefined
Invalid
1 0 0 0 0
Invalid
undefined
Invalid
1 1 0 0 1
Invalid
Table 46
4B/5B Coding
Code Type
4B Code
3 2 1 0
Name
5B Code
4 3 2 1 0
Interpretation
1. The /I/ (Idle) code group is sent continuously between frames.
2. The /J/ and /K/ (SSD) code groups are always sent in pairs; /K/ follows /J/.
3. The /T/ and /R/ (ESD) code groups are always sent in pairs; /R/ follows /T/.
4. An /H/ (Error) code group is used to signal an error condition.