LAN8720A-CP-TR SMSC, LAN8720A-CP-TR Datasheet - Page 17

• Manufacturer Part Number: LAN8720A-CP-TR
• Description: Ethernet ICs RMII 10/100 ETH XCVR w/HP AutoMDIXSupport
• Manufacturer: SMSC

Specifications of LAN8720A-CP-TR

• Product: Ethernet Transceivers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
SMSC LAN8720A/LAN8720Ai
Chapter 3 Functional Description
3.1
3.1.1
3.1.1.1
MAC
This chapter provides functional descriptions of the various device features. These features have been
categorized into the following sections:
100BASE-TX Transmit
The 100BASE-TX transmit data path is shown in
following subsections.
100BASE-TX Transmit Data Across the RMII Interface
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.
Transceiver
125 Mbps Serial
Transceiver
Auto-negotiation
HP Auto-MDIX Support
MAC Interface
Serial Management Interface (SMI)
Interrupt Management
Configuration Straps
Miscellaneous Functions
Application Diagrams
RMII 50Mhz by 2 bits
Ext Ref_CLK
Figure 3.1 100BASE-TX Transmit Data Path
Converter
MLT-3
NRZI
Magnetics
DATASHEET
RMII
NRZI
17
Converter
PLL
by 4 bits
MLT-3
25MHz
MLT-3
Figure
Encoder
4B/5B
MLT-3
RJ45
3.1. Each major block is explained in the
25MHz by
Driver
5 bits
Tx
MLT-3
Scrambler
Revision 1.2 (11-10-10)
and PISO
CAT-5