KSZ8995MA B3 Micrel Inc, KSZ8995MA B3 Datasheet - Page 60

• Manufacturer Part Number: KSZ8995MA B3
• Manufacturer: Micrel Inc

Specifications of KSZ8995MA B3

• Number Of Primary Switch Ports: 5
• Internal Memory Buffer Size: 64
• Operating Supply Voltage (typ): 1.8/2.5/3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII/SNI
• Power Supply Type: Analog/Digital
• Package Type: PQFP
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Compliant

Semptember 2008
VLAN Address
The VLAN table is used for VLAN table look-up. If 802.1q VLAN mode is enabled (Register 5 bit 7 = 1), this table is
used to retrieve VLAN information that is associated with the ingress packet. The information includes FID (filter ID),
VID (VLAN ID), and VLAN membership described below:
If 802.1q VLAN mode is enabled, KS8995MA/FQ assigns a VID to every ingress packet. If the packet is untagged or
tagged with a null VID, the packet is assigned with the default port VID of the ingress port. If the packet is tagged with
non-null VID, the VID in the tag is used. The look-up process starts from the VLAN table look-up. If the VID is not
valid, the packet is dropped and no address learning occurs. If the VID is valid, the FID is retrieved. The FID+DA and
FID+SA lookups are performed. The FID+DA look-up determines the forwarding ports. If FID+DA fails, the packet is
broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails, the FID+SA is learned.
Examples:
Note:
The sequence of the writing entries should start from entry 0. Improper sequence of the VLAN enties could cause the VLAN to be non-functional.
Address
Format of Static VLAN Table (16 entries)
21
20-16
15-12
11-0
(1) VLAN Table Read (read the 3rd entry)
(2) VLAN Table Write (write the 7th entry)
Write to Register 110 with 0x14 (read VLAN table selected)
Write to Register 111 with 0x2 (trigger the read operation)
Then
Read Register 118 (VLAN table bits 21-16)
Read Register 119 (VLAN table bits 15-8)
Read Register 120 (VLAN table bits 7-0)
Write to Register 118 (VLAN table bits 21-16)
Write to Register 119 (VLAN table bits 15-8)
Write to Register 120 (VLAN table bits 7-0)
Write to Register 110 with 0x04 (write VLAN table selected)
Write to Register 111 with 0x6 (trigger the write operation)
Name
Valid
Membership
FID
VID
Description
0, entry is invalid.
If a DA look-up fails (no match in both static and
dynamic tables), the packet associated with this VLAN
will be forwarded to ports specified in this field.
E.g., 11001 means port 5, 4, and 1 are in this VLAN.
represented by these four bit fields. FID is the mapped
ID. If 802.1q VLAN is enabled, the look-up will be
based on FID+DA and FID+SA.
1, the entry is valid.
Specify which ports are members of the VLAN.
Filter ID. KS8995MA/FQ supports 16 active VLANs
IEEE 802.1q 12 bit VLAN ID.
Table 11. VLAN Table
60
Mode
R/W
R/W
R/W
R/W
M9999-091508
Default
11111
1
0
1