SMSC LAN8720i User Manual

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support

SMSC LAN8720/LAN8720i

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Revision 1.0 (05-28-09)

The following is list of the general terms used in this document:

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.

8-bits

First In First Out buffer; often used for elasticity buffer

Media Access Controller

Media Independent Interface

TM

 

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