Cirrus Logic CS8952 - Manual (Page 21)

CS8952
CrystalLAN™ 100BASE-X and 10BASE-T Transceiver 21
DS206F1
Table 2. 4B5B Symbol Encoding/Decoding
2 10100 0010
3 10101 0011
4 01010 0100
5 01011 0101
6 01110 0110
7 01111 0111
8 10010 1000
9 10011 1001
A 10110 1010
B 10111 1011
C 11010 1100
D 11011 1101
E 11100 1110
F 11101 1111
CONTROL (Note 2)
I 11111 0101 IDLE (Note 3)
J 11000 0101 First Start of Stream Symbol
K 10001 0101 Second Start of Stream Symbol
T 01101 0000 First End of Stream Symbol
R 00111 0000 Second End of Stream Symbol
1. DATA code groups are indicated by RX_DV = 1
2. CONTROL code groups are inserted automatically during transmission in response to
TX_EN. They are not generated through any combination of TXD[3:0] or TX_ER.
3. IDLE is indicated by RX_DV = 0.
Code Violations (RX_ER = 1 or TX_ER = 1)
Name 5-bit Symbol
Normal Mode 4-bit
Nibble
Error Report
Mode 4-bit
Nibble Comments
CONTROL (Note 1)
I 11111 0000 0000 This portion of the table relates received
5-bit symbols to received 4-bit nibbles
only. The control code groups may not
be transmitted in the data portion of the
frame.
J 11000 0000 0000
K 10001 0000 0000
T 01101 0000 0000
R 00111 0000 0000
CODE VIOLATIONS
H 00100 0000 0000
V0 00000 0110 or 0101 (Note 2) 0001
V1 00001 0110 or 0101 (Note 2) 0111
V2 00010 0110 or 0101 (Note 2) 1000
V3 00011 0110 or 0101 (Note 2) 1001
V4 00101 0110 or 0101 (Note 2) 1010
V5 00110 0110 or 0101 (Note 2) 1011
DATA and CONTROL Codes (RX_ER = 0 or TX_ER = 0)
Name 5-bit Symbol 4-bit Nibble Comments