lan9313 Standard Microsystems Corp., lan9313 Datasheet - Page 81

• Manufacturer Part Number: lan9313
• Description: Lan9313/lan9313i Three Port 10/100 Managed Ethernet Switch With Mii
• Manufacturer: Standard Microsystems Corp.

Three Port 10/100 Managed Ethernet Switch with MII
Datasheet
SMSC LAN9313/LAN9313i
The tagging/un-tagging rules are specified as follows:
For clarity, the following details the incoming un-tag instruction. As described in
Support," on page
VLAN table, selected by the ingress port number. The entry in the VLAN table is either the VLAN from
the received packet or the ingress ports default VID.
Dumb Port - This port type generally does not change the tag.
untouched.
Access Port - This port type generally does not support tagging.
CPU Port - Packets transmitted from this port type generally contain a special tag. Special tags
are described in detail in
Hybrid Port - Generally, this port type supports a mix of normal-tagged and non-tagged packets.
It is the most complex, but most flexible port type.
When a received packet is non-tagged, a new VLAN tag is added if two conditions are met. First,
the Insert Tag bit for the egress port in the
(BM_EGRSS_PORT_TYPE)
ingress ports default VID must be cleared. The VLAN tag that is added will have a VID and Priority
taken from the ingress ports default VID and priority.
When a received packet is priority-tagged, either the tag is removed or it is modified.
VID. If the Change Priority bit in the
(BM_EGRSS_PORT_TYPE)
is also changed to the ingress ports default priority.
When a received packet is normal-tagged, either the tag is removed, modified, or passed.
removed.
(BM_EGRSS_PORT_TYPE)
Type Register (BM_EGRSS_PORT_TYPE)
untouched.
the new VLAN tag is changed to the egress ports default ID. If the Change Priority bit for the egress
port is set, the Priority field of the new VLAN is changed to the egress ports default priority.
When a packet is received special-tagged from a CPU port, the special tag is removed.
When a received packet is non-tagged, priority-tagged, or normal-tagged, the packet passes
When a packet is received special-tagged from a CPU port, the special tag is removed.
When a received packet in non-tagged, the packet passes untouched.
When a received packet is priority-tagged or normal-tagged, the tag is removed.
When a received packet is special-tagged from a CPU port, the special tag is removed.
If the un-tag instruction associated with the ingress ports default VID is set, then the tag is removed.
Otherwise, the tag is modified. The VID of the new VLAN tag is changed to the ingress ports default
If the un-tag instruction associated with the VID in the received packet is set, then the tag is
Else, if the Change Tag bit in the
Else, if both the Change VLAN ID and the Change Priority bits in the
Otherwise, the tag is modified. If the Change VLAN ID bit for the egress port is set, the VOD of
72, the un-tag instruction is one of three un-tag bits from the applicable entry in the
Section 6.4.10, "Host CPU Port Special Tagging," on page
must be set. Second, the un-tag instruction associated with the
for the egress port is set, then the Priority field of the new VLAN tag
for the egress port is clear, the packet is untouched.
DATASHEET
Buffer Manager Egress Port Type Register
Buffer Manager Egress Port Type Register
81
Buffer Manager Egress Port Type Register
for the egress port are clear, the packet passes
Buffer Manager Egress Port
Section 6.4.4, "VLAN
Revision 1.2 (04-08-08)
77.