EVB9303 SMSC, EVB9303 Datasheet - Page 90

• Manufacturer Part Number: EVB9303
• Description: EVALUATION BOARD FOR LAN9303
• Manufacturer: SMSC

Specifications of EVB9303

• Main Purpose: Interface, Ethernet
• Embedded: No
• Utilized Ic / Part: LAN9303
• Primary Attributes: 3 Ports, 100BASE-TX/10BASE-T, Managed
• Secondary Attributes: Full Duplex and HP Auto-MDIX Support, 10BASE-T and 100BASE-TX
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 638-1095

Revision 1.4 (07-07-10)
7.2.1
7.2.1.1
7.2.1.2
Port x
MAC
Converter
NRZI
100BASE-TX Transmit
The 100BASE-TX transmit data path is shown in
internal to the PHY. Each major block is explained in the following sections.
MII MAC Interface
For a transmission, the Switch Fabric MAC drives the transmit data to the PHYs MII MAC Interface.
The MII MAC Interface is described in detail in
Note: The PHY is connected to the Switch Fabric MAC via standard MII signals. Refer to the IEEE
4B/5B Encoder
The transmit data passes from the MII 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.
RJ45
MII 25 MHz by 4 bits
MII Transmit Clock
802.3 specification for additional details.
NRZI
Internal
Internal
MLT-3
Converter
MLT-3
Figure 7.2 100BASE-TX Transmit Data Path
MII MAC
Interface
CAT-5
Small Form Factor Three Port 10/100 Managed Ethernet Switch with Single MII/RMII/Turbo MII
100M
PLL
MLT-3
DATASHEET
125 Mbps Serial
MLT-3
by 4 bits
90
25MHz
TX Driver
100M
Section 7.2.7, "MII MAC
Figure
Encoder
4B/5B
7.2. Shaded blocks are those which are
MLT-3
Table
25MHz by
Magnetics
5 bits
Interface".
7.2. Each 4-bit data-nibble
SMSC LAN9303/LAN9303i
Scrambler
and PISO
Datasheet