LAN8710A Datasheet, PDF (19/82 Pages) SMSC Corporation – Small Footprint MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR Technology

Small Footprint MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR^® Technology
Datasheet
Chapter 3 Functional Description
This chapter provides functional descriptions of the various device features. These features have been
categorized into the following sections:
„ Transceiver
„ Auto-negotiation
„ HP Auto-MDIX Support
„ MAC Interface
„ Serial Management Interface (SMI)
„ Interrupt Management
„ Configuration Straps
„ Miscellaneous Functions
„ Application Diagrams
3.1
3.1.1
Transceiver
100BASE-TX Transmit
The 100BASE-TX transmit data path is shown in Figure 3.1. Each major block is explained in the
following subsections.
MAC
TX_CLK
(for MII only)
PLL
Ext Ref_CLK (for RMII only)
MII 25 Mhz by 4 bits
or
RMII 50Mhz by 2 bits
MII/RMII
25MHz
by 4 bits
4B/5B
Encoder
25MHz by Scrambler
5 bits _{and PISO}
125 Mbps Serial
NRZI
Converter
NRZI
MLT-3
Converter ^MLT-3
Tx
Driver
MLT-3 Magnetics MLT-3
RJ45
MLT-3
CAT-5
3.1.1.1
Figure 3.1 100BASE-TX Transmit Data Path
100BASE-TX Transmit Data Across the MII/RMII Interface
For MII, the MAC controller drives the transmit data onto the TXD bus and asserts TXEN to indicate
valid data. The data is latched by the transceiver’s MII block on the rising edge of TXCLK. The data
is in the form of 4-bit wide 25MHz data.
SMSC LAN8710A/LAN8710Ai
19
DATASHEET
Revision 1.4 (08-23-12)