DS33X11+ Maxim Integrated Products, DS33X11+ Datasheet - Page 68

• Manufacturer Part Number: DS33X11+
• Description: IC MAPPING ETHERNET 144CSBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS33X11+

• Applications: Data Transport
• Interface: SPI
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Package / Case: 144-CSBGA
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

________________________________________________ DS33X162/X161/X82/X81/X42/X41/X11/W41/W11
8.16.2 Programming the VLAN ID Table
A 4 kilobyte user-configured “VLAN Table” is used to translate VLAN tag information from each received frame into
forwarding, trapping (frame extraction), or discarding decisions. Each address in the table corresponds to a
specific VLAN ID (VID) value from 0 to 4095, and the bit settings at each address relate to actions taken when a
frame containing the corresponding VLAN ID value is detected. The VLAN Table is configured through the
SU.VTC, SU.VTAA, SU.VTWD, and SU.VTRD registers.
Within each address location in the VLAN table, two bits of data determine the actions taken for frames received on
the WAN interfaces with VLAN IDs matching the table address value, and four bits determine actions taken on
frames received on the LAN interfaces with VLAN IDs matching the table address value. The 4K x 2 bit space used
for WAN functions is referred to as the WAN-VLAN table. The 4 K x 4 bit space used for LAN functions is referred
to as the LAN-VLAN table.
The user can also configure a default “No VLAN detected” value in the SU.LNFC register to indicate what should
be done with frames that do not have a VLAN tags. The user may indicate the same forwarding location as one of
the other VLAN Groups, or it can be used to indicate an independent process or location. For example, the user
may indicate to discard untagged frames, while VLAN tags 0 through 4094 are forwarded to the 4 WAN Groups
and VLAN tag 4095 is forwarded to the LAN Extract queue.
To Reset the VLAN Table:
1) Write SU.VTC = 05h to ensure a 0-1 transition on SU.VTC.CI and enable the VLAN Table.
2) Write SU.VTC = 07h.
3) Read SU.VTSA.VTIS until = 1.
To Program the VLAN Table:
1) Write SU.VTAA = 00h in order to begin configuration at VID 00h.
2) 4096 times, write the value of SU.VTWD for the desired action for each VID value.
To Verify the VLAN Table:
1) Write SU.VTAA = 00h in order to begin verification at VID 00h.
2) 4096 times, read the value of SU.VTRD register and verify the value.
The LAN-VLAN ID frame extraction trap must be assigned to an Ethernet Port with the SU.LPM.LEEPS bit, and
enabled with the SU.LPM.LEVIT bit.
The WAN-VLAN ID frame extraction trap must be assigned to a specific WAN Group (Decapsulator) with the
SU.WEM.WEDS bits and enabled with the SU.WEM.WEVIT bit.
In order to enable the VLAN processing functions in each port, the
SU.LP1C.LP1ETF[2:1] or
SU.LP2C.LP2ETF[2:1] bits must be properly configured. When the VLAN processing functions are enabled,
incoming frames are inspected for VLAN information. The VLAN protocol ID must match the value programmed in
SU.LQTPID. Frames with alternate VLAN PIDs are processed as “untagged”. In the WAN-to-LAN direction, the
corresponding function is performed in SU.WETPID.
Rev: 063008
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