SMSC LAN9420 - Manual (Page 138)

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
Revision 1.22 (09-25-08) 138 SMSC LAN9420/LAN9420i
DATASHEET
4.5.3 PHY Identifier 1
Index (In Decimal): 2 Size: 16 bits
BITS DESCRIPTION TYPE DEFAULT
15:0 PHY ID Number
Assigned to the 3rd through 18th bits of the Organizationally Unique
Identifier (OUI), respectively. R/W 0007h