LAN9420 Datasheet, PDF (131/171 Pages) SMSC Corporation – Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface

Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
4.4.9 VLAN1 Tag Register (VLAN1)
Offset:
00A0h
Size:
32 bits
This register contains the VLAN tag field to identify VLAN1 frames. For VLAN frames the legal frame
length is increased from 1518 bytes to 1522 bytes.
The RXCOE also uses this register to determine the protocol value to use to indicate the existence of
a VLAN tag. When using the RXCOE, this value may only be changed if the RX path is disabled. If it
is desired to change this value during run time, it is safe to do so only after the MAC is disabled and
the MIL is empty.
BITS
31:16
15:0
DESCRIPTION
RESERVED
VLAN1 Tag Identifier (VTI1)
This contains the VLAN Tag field to identify the VLAN1 frames. This field is
compared with the 13^th and 14^th bytes of the incoming frames for VLAN1
frame detection.
TYPE
RO
R/W
DEFAULT
-
FFFFh
SMSC LAN9420/LAN9420i
131
DATASHEET
Revision 1.6 (07-18-11)