EP82562ET Datasheet, PDF (14/40 Pages) Intel Corporation – 10/100 Mbps Platform LAN Connect (PLC)

82562ET — Networking Silicon
4.1.1.2
Symbol
6
7
8
9
A
B
C
D
E
F
I
J
K
T
R
V
V
V
V
H
V
V
V
V
V
V
5B Symbol Code
4B Nibble Code
01110
01111
10010
10011
10110
10111
11010
11011
11100
11101
11111
11000
10001
01101
00111
00000
00001
00010
00011
00100
00101
00110
01000
01100
10000
11001
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Inter Packet Idle Symbol
(No 4B)
1st Start of Packet Symbol
0101
2nd Start of Packet Symbol
0101
1st End of Packet Symbol
2nd End of Packet Symbol
and Flow Control
INVALID
INVALID
INVALID
INVALID
INVALID
INVALID
INVALID
INVALID
INVALID
Flow Control S
INVALID
100BASE-TX Scrambler and MLT-3 Encoder
Data is scrambled in 100BASE-TX in order to reduce electromagnetic emissions during long
transmissions of high-frequency data codes. The scrambler logic accepts 5 bits from the 4B/5B
encoder block and presents the scrambled data to the MLT-3 encoder. The 82562ET implements
the 11-bit stream cipher scrambler as adopted by the ANSI XT3T9.5 committee for UTP operation.
The cipher equation used is:
X[n] = X[n-11] + X[n-9] (mod 2)
The MLT-3 encoder receives the scrambled Non-Return to Zero (NRZ) data stream from the
scrambler and encodes the stream into MLT-3 for presentation to the driver. MLT-3 is similar to
NRZ1 coding, but three levels are output instead of two. The three output levels are positive,
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Datasheet