Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

Datasheet

14.3.10Host MAC VLAN2 Tag Register (HMAC_VLAN2)

Offset:

Ah

Size:

32 bits

This read/write register contains the VLAN tag field to identify VLAN2 frames. When a VLAN2 frame is detected, the legal frame length is increased from 1518 bytes to 1538 bytes. Refer to Section 9.3, "Virtual Local Area Network (VLAN) Support," on page 114 for additional information.

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

31:16

RESERVED

RO

-

 

 

 

 

15:0

VLAN2 Tag Identifier (VTI2)

R/W

FFFFh

 

This field contains the VLAN Tag used to identify VLAN2 frames. This field

 

 

 

is compared with the 13th and 14th bytes of the incoming frames for VLAN2

 

 

 

frame detection.

 

 

 

Note: If used, this register is typically set to the standard VLAN value of

 

 

 

8100h. If both VLAN1 and VLAN2 Tag Identifiers are used, they

 

 

 

should be unique. If both are set to the same value, VLAN1 is

 

 

 

given higher precedence and the maximum legal frame length is

 

 

 

set to 1522.

 

 

 

 

 

 

Revision 1.4 (08-19-08)

284

SMSC LAN9311/LAN9311i

 

DATASHEET