LAN8710 Datasheet, PDF (19/79 Pages) SMSC Corporation – MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR Technology in a Small Footprint

MII/RMII 10/100 Ethernet Transceiver with HP Auto-MDIX and flexPWR^® Technology in a Small Footprint
Datasheet
Chapter 4 Architecture Details
4.1
Top Level Functional Architecture
Functionally, the transceiver can be divided into the following sections:
„ 100Base-TX transmit and receive
„ 10Base-T transmit and receive
„ MII or RMII interface to the controller
„ Auto-negotiation to automatically determine the best speed and duplex possible
„ Management Control to read status registers and write control registers
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
M II/R M II
25MHz
by 4 bits
4B/5B
Encoder
25MHz by
5 bits
S cra m b le r
and PISO
125 Mbps Serial
NRZI
C o n ve rte r
NRZI
M LT -3
C o n ve rte r
M LT -3
Tx
Driver
MLT-3 M agnetics MLT-3
RJ45
Figure 4.1 100Base-TX Data Path
M LT-3
CAT-5
4.2
4.2.1
100Base-TX Transmit
The data path of the 100Base-TX is shown in Figure 4.1. Each major block is explained below.
100M 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.
For RMII, 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 RMII block on the rising edge of REF_CLK. The
data is in the form of 2-bit wide 50MHz data.
SMSC LAN8710/LAN8710i
19
DATASHEET
Revision 1.0 (04-15-09)