Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface

Datasheet

Table 3.21 4B/5B Code Table (continued)

CODE

 

 

 

RECEIVER

 

TRANSMITTER

GROUP

SYM

 

INTERPRETATION

 

INTERPRETATION

 

 

 

 

 

 

 

 

 

10010

8

8

 

1000

 

8

 

1000

 

 

 

 

 

 

 

 

 

 

 

10011

9

9

 

1001

 

9

 

1001

 

 

 

 

 

 

 

 

 

 

 

10110

A

A

 

1010

 

A

 

1010

 

 

 

 

 

 

 

 

 

 

 

10111

B

B

 

1011

 

B

 

1011

 

 

 

 

 

 

 

 

 

 

 

11010

C

C

 

1100

 

C

 

1100

 

 

 

 

 

 

 

 

 

 

 

11011

D

D

 

1101

 

D

 

1101

 

 

 

 

 

 

 

 

 

 

 

11100

E

E

 

1110

 

E

 

1110

 

 

 

 

 

 

 

 

 

 

 

11101

F

F

 

1111

 

F

 

1111

 

 

 

 

 

 

 

 

 

 

11111

I

IDLE

 

 

 

Sent after /T/R until TX_EN

 

 

 

 

11000

J

First nibble of SSD, translated to “0101”

Sent for rising TX_EN

 

 

following IDLE, else RX_ER

 

 

 

 

 

 

 

 

10001

K

Second nibble of SSD, translated to

Sent for rising TX_EN

 

 

“0101” following J, else RX_ER

 

 

 

 

 

 

 

 

01101

T

First nibble of ESD, causes de-assertion

Sent for falling TX_EN

 

 

of CRS if followed by /R/, else assertion

 

 

 

 

 

 

of RX_ER

 

 

 

 

 

 

 

 

 

 

 

00111

R

Second nibble of ESD, causes de-

Sent for falling TX_EN

 

 

assertion of CRS if following /T/, else

 

 

 

 

 

 

assertion of RX_ER

 

 

 

 

 

 

 

 

00100

H

Transmit Error Symbol

Sent for rising TX_ER

 

 

 

 

 

 

 

00110

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

11001

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

00000

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

00001

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

00010

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

00011

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

00101

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

01000

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

01100

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

10000

V

INVALID, RX_ER if during RX_DV

INVALID

 

 

 

 

 

 

 

 

 

 

 

 

 

3.6.1.2Scrambling

Repeated data patterns (especially the IDLE code-group) can have power spectral densities with large narrow-band peaks. Scrambling the data helps eliminate these peaks and spread the signal power more uniformly over the entire channel bandwidth. This uniform spectral density is required by FCC regulations to prevent excessive EMI from being radiated by the physical wiring.

The scrambler also performs the Parallel In Serial Out conversion (PISO) of the data.

Revision 1.22 (09-25-08)

66

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