DM9016
3-port switch with Processor Interface
as “sniffer port”. If a packet is received form port 0
and predestined to port 1 after forwarding decision,
the DM9016 will forward it to port 1 and port 3 in the
end.
mapped to register B0h~BFh, to define the VLAN
groups.
For instance, we intend to partition DM9016’s
ports into three groups. Port 0 and port 1 in group A,
port 1 and port 2 in group B, finally, port 2 and port 3
in group C. In this case, the setting as below:
(3).Transmit monitor
All packets transmitted on the “transmit monitor
port” are send a copy to “sniffer port”. For example,
port 1 is set as “transmit monitor port” and port 3 is
selected as “sniffer port”. If a packet is received from
port 0 and predestined to port 1 after forwarding
decision, the DM9016 will forward it to port 1 and port
3 in the end.
(1). Set PVID of Port 0 to 0x01h.
(2). Set PVID of Port 1 to 0x02h.
(3). Set PVID of Port 2 to 0x03h.
(4). Set PVID of Port 3 to 0x04h.
(5). Set register B1h to 0x02h.
(6). Set register B2h to 0x05h.
(7). Set register B3h to 0x0Ah.
(8). Set register B4h to 0x04h.
(4).Exception
The DM9016 has an optional setting that
broadcast/multicast packets are not monitored (see
bit 4 of register 65h). It’s useful to avoid unnecessary
bandwidth.
9.2.13.2 802.1Q-Based VLAN
Regarding IEEE 802.1Q standard, Tag-based
VLAN uses an extra tag to identify the VLAN
9.2.13 VLAN Support
membership of
a
frame across VLAN-aware
switch/router. A tagged frame is four bytes longer
than an untagged frame and contains two bytes of
TPID (Tag Protocol Identifier) and two bytes of TCI
(Tag Control Information).
9.2.13.1 Port-Based VLAN
The DM9016 supports port-based VLAN as
default, up to 16 groups. Each port has a default VID
called PVID (Port VID, see register 6Fh). The
DM9016 used LSB 4-bytes of PVID as index and
Dest.
Dest.
Src.
Src.
Length/Type
Data
Standard frame
Tagged frame
TPID
Type
Length /
Data
TCI
0x8100
2 bytes
Priority CFI
VID
3 bits
1 bits
12 bits
The DM9016 also supports 16 802.1Q-based
VLAN groups, as specified in bit 1 of register 53h. It’s
obvious that the tagged packets can be assigned to
several different VLANs which are determined
according to the VID inside the VLAN Tag. Therefore,
the operation is similar to port-based VLAN. The
DM9016 used LSB 4-bytes VID of received packet
with VLAN tag and VLAN Group Mapping Register
(B0h~BFh) to configure the VLAN partition. If the
destination port of received packet is not same VLAN
group with received port, it will be discarded.
Preliminarydatasheet
DM9016-13-DS-P01
March 26, 2009
65
DAVICOM [ DAVICOM SEMICONDUCTOR, INC. ]
