Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
Chapter 1 Introduction
1.1
General Terms and Conventions
The following is list of the general terms used in this document:
BYTE
FIFO
MAC
MII
RMII
TM
N/A
X
RESERVED
8-bits
First In First Out buffer; often used for elasticity buffer
Media Access Controller
Media Independent Interface
Reduced Media Independent Interface
TM
Not Applicable
Indicates that a logic state is “don’t care” or undefined.
Refers to a reserved bit field or address. Unless otherwise noted, reserved
bits must always be zero for write operations. Unless otherwise noted, values
are not guaranteed when reading reserved bits. Unless otherwise noted, do
not read or write to reserved addresses.
Serial Management Interface
SMI
1.2
General Description
The LAN8720/LAN8720i is a low-power 10BASE-T/100BASE-TX physical layer (PHY) transceiver that
transmits and receives on unshielded twisted-pair cable. A typical system application is shown in
It is available in both extended commercial and industrial temperature operating versions.
The LAN8720/LAN8720i interfaces to the MAC layer using a variable voltage digital interface via the
RMII interface. The digital interface pins are tolerant to 3.6V.
The LAN8720/LAN8720i implements Auto-Negotiation to automatically determine the best possible
speed and duplex mode of operation. HP Auto-MDIX support allows using a direct connect LAN cable,
or a cross-over path cable.
The LAN8720 referenced throughout this document applies to both the extended commercial
temperature and industrial temperature components. The LAN8720i refers to only the industrial
temperature component.
SMSC LAN8720/LAN8720i
9
Revision 1.0 (05-28-09)
DATASHEET
SMSC [ SMSC CORPORATION ]
