FLLXT971ABC.A4 Intel, FLLXT971ABC.A4 Datasheet - Page 51

• Manufacturer Part Number: FLLXT971ABC.A4
• Manufacturer: Intel

Specifications of FLLXT971ABC.A4

• Lead Free Status / RoHS Status: Not Compliant

5.7.3.1
Datasheet
Document Number: 249414-003
Revision Date: June 18, 2004
Table 14. 4B/5B Coding (Sheet 1 of 2)
Physical Coding Sublayer
The Physical Coding Sublayer (PCS) provides the MII interface, as well as the 4B/5B encoding/
decoding function.
For 100BASE-TX and 100BASE-FX operation, the PCS layer provides IDLE symbols to the
PMD-layer line driver as long as TX_EN is de-asserted.
5.7.3.1.1 Preamble Handling
When the MAC asserts TX_EN, the PCS substitutes a /J/K symbol pair, also known as the Start-of-
Stream Delimiter (SSD), for the first two nibbles received across the MII. The PCS layer continues
to encode the remaining MII data, following the 4B/5B coding in
asserted. It then returns to supplying IDLE symbols to the line driver.
In the receive direction, the PCS layer performs the opposite function, substituting two preamble
nibbles for the SSD. In 100 Mbps operation, preamble is always passed through the PCS layer to
the MII interface.
1. The /I/ (Idle) code group is sent continuously between frames.
2. The /J/ and /K/ (SSD) code groups are always sent in pairs, and /K/ follows /J/.
3. The /T/ and /R/ (ESD) code groups are always sent in pairs, and /R/ follows /T/.
4. An /H/ (Error) code group is used to signal an error condition.
Code Type
DATA
IDLE
undefined
4B Code
3 2 1 0
0 0 0 0
0 0 0 1
0 0 1 0
0 0 1 1
0 1 0 0
0 1 0 1
0 1 1 0
0 1 1 1
1 0 0 0
1 0 0 1
1 0 1 0
1 0 1 1
1 1 0 0
1 1 0 1
1 1 1 0
1 1 1 1
Intel
Name
®
I
A
B
C
D
E
0
1
2
3
4
5
6
7
8
9
F
1
LXT971A Single-Port 10/100 Mbps PHY Transceiver
5B Code
4 3 2 1 0
1 1 1 1 0
0 1 0 0 1
1 0 1 0 0
1 0 1 0 1
0 1 0 1 0
0 1 0 1 1
0 1 1 1 0
0 1 1 1 1
1 0 0 1 0
1 0 0 1 1
1 0 1 1 0
1 0 1 1 1
1 1 0 1 0
1 1 0 1 1
1 1 1 0 0
1 1 1 0 1
1 1 1 11
Used as inter-stream fill code
Table
14, until TX_EN is de-
Interpretation
Data C
Data D
Data A
Data B
Data E
Data F
Data 0
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
Data 7
Data 8
Data 9
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