MDS213 Datasheet, PDF (55/120 Pages) Zarlink Semiconductor Inc – 12-Port 10/100Mbps + 1Gbps Ethernet Switch

MDS213
14.2.4 MDS213 Data Structures For VLAN Implementation
63
0
FDB
Frame Data Buffers
Data Sheet
FDB block must start from 0
Transmission queues
Programmable Size
External RAM
CPU/HISC Mailing List
Programmable Size
VLAN ID Table
(4k entry, 8B/entry)
32KB
MAX
1/2MB, 1MB or 2MB
VLAN MAC Table
(2k entry, 256/128/64 bit)
Byte Byte Byte ByteByte ByteByte Byte
765 4321 0
64, 32 or 16KB
(up to the number of
supported VLAN)
Figure 20 - Data Structure Diagram
14.2.4.1 VLAN ID Table
The VLAN ID Table is used by Search Engine for unicast frames. The base address of this table is specified by
VIDB subfield in BIT[5:0] of VTBP register.
The contents of this table are set up by the MDS213's microcode through the command of CPU software at the time
of VLAN creation and deletion. The VLAN ID Table covers the entire 4K VLAN ID space, and is used by the Search
Engine to map the VLAN ID into an internal VLAN Index. It also includes port membership and port tagging
information for each VLAN. Each VLAN ID entry is 8 bytes long, and the total size of the VLAN ID Table is 32KB.
The VLAN ID table must be located at the 32K boundary.
Byte ^{3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 9 8 7 6 5 4 3 2 1 0}
1098765432109876543210
0 _Index[3: C V P12P11 P10 P9 P8 P7 P6 P5 P4 P3 P2 P1 T S
0]
4
Index[7:
4]
P28
P17P16
Bit[1:0] P0VLAN Status for Port 0
Figure 21 - VLAN ID Table
Bit [0]SThis port is a member of this VLAN
Bit [1]TTagout
Bit[3:2] P1 VLAN status for Port 1
….
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