SMSC LAN9312 - Manual (Page 291)

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312 291 Revision 1.4 (08-19-08)
DATASHEET
14.4.2.3 Port x PHY Identification MSB Register (PHY_ID_MSB_x)
This read/write register contains the MSB of the Organizationally Unique Identifier (OUI) for the Port x
PHY. The LSB of the PHY OUI is contained in the
Port x PHY Identification LSB Register
(PHY_ID_LSB_x) .
Index (decimal): 2 Size: 16 bits
BITS DESCRIPTION TYPE DEFAULT
15:0 PHY ID
This field is assigned to the 3rd through 18th bits of the OUI, respectively
(OUI = 00800Fh). R/W 0007h