LAN8720AI-CP SMSC, LAN8720AI-CP Datasheet - Page 18

• Manufacturer Part Number: LAN8720AI-CP
• Description: TXRX ETHERNET 10/100 RMII 24QFN
• Manufacturer: SMSC
• Type: Transceiverr

Specifications of LAN8720AI-CP

• Number Of Drivers/receivers: 4/4
• Protocol: RMII
• Voltage - Supply: 1.6 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 24-QFN
• Product: Ethernet Transceivers
• Standard Supported: 802.3, 802.3u
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.6 V
• Maximum Operating Temperature: + 85 C
• Ethernet Connection Type: 10/100 Base-T
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 638-1084

Revision 1.2 (11-10-10)
3.1.1.2
GROUP
CODE
01001
10100
10101
01010
01011
10010
10011
10110
11010
11000
10001
01101
00100
00110
01110
10111
11011
11100
11101
00111
11110
01111
11111
4B/5B Encoding
The transmit data passes from the RMII block to the 4B/5B encoder. This block encodes the data from
4-bit nibbles to 5-bit symbols (known as “code-groups”) according to
is mapped to 16 of the 32 possible code-groups. The remaining 16 code-groups are either used for
control information or are not valid.
The first 16 code-groups are referred to by the hexadecimal values of their corresponding data nibbles,
0 through F. The remaining code-groups are given letter designations with slashes on either side. For
example, an IDLE code-group is /I/, a transmit error code-group is /H/, etc.
SYM
A
B
C
D
E
R
H
V
0
1
2
3
4
5
6
7
8
9
F
K
T
J
I
IDLE
First nibble of SSD, translated to “0101”
following IDLE, else RXER
Second nibble of SSD, translated to
“0101” following J, else RXER
First nibble of ESD, causes de-assertion
of CRS if followed by /R/, else assertion
of RXER
Second nibble of ESD, causes
deassertion of CRS if following /T/, else
assertion of RXER
Transmit Error Symbol
INVALID, RXER if during RXDV
A
B
C
D
E
0
1
2
3
4
5
6
7
8
9
F
INTERPRETATION
Table 3.1 4B/5B Code Table
RECEIVER
0000
0001
0010
0011
0100
0101
0110
1000
1001
1010
1011
1100
1101
0111
1110
1111
DATASHEET
18
DATA
Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Sent after /T/R until TXEN
Sent for rising TXEN
Sent for rising TXEN
Sent for falling TXEN
Sent for falling TXEN
Sent for rising TXER
INVALID
A
B
C
D
E
0
1
2
3
4
5
6
7
8
9
F
Table
INTERPRETATION
TRANSMITTER
3.1. Each 4-bit data-nibble
SMSC LAN8720A/LAN8720Ai
0000
0001
0010
0100
0101
1000
1001
1010
0011
0110
0111
1011
1100
1101
1110
1111
DATA
Datasheet