KSZ8842-PMBL AM TR Micrel Inc, KSZ8842-PMBL AM TR Datasheet - Page 108

• Manufacturer Part Number: KSZ8842-PMBL AM TR
• Description: 2-Port Ethernet Switch/Repeater + 32-bit/33MHz PCI Bus Interface( )
• Manufacturer: Micrel Inc

Specifications of KSZ8842-PMBL AM TR

• Number Of Primary Switch Ports: 2
• Internal Memory Buffer Size: 32
• Operating Supply Voltage (typ): 3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII
• Power Supply Type: Analog/Digital
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Mounting: Surface Mount
• Jtag Support: No
• Operating Supply Voltage (max): 3.5V
• Operating Supply Voltage (min): 3.1V
• Operating Temperature Classification: Industrial
• Data Rate: 100Mbps
• Lead Free Status / RoHS Status: Supplier Unconfirmed

Micrel, Inc.
VLAN Table
The KSZ8842-PMQL/PMBL uses the VLAN table to perform look ups. If 802.1Q VLAN mode is enabled (SGCR2[15]),
this table will be used to retrieve the VLAN information that is associated with the ingress packet. This information
includes FID (filter ID), VID (VLAN ID), and VLAN membership as described in table 14:
If 802.1Q VLAN mode is enabled, KSZ8842-PMQL/PMBL will assign 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 will be used. The look up process will start from the VLAN table look up. If
the VID is not valid, the packet will be dropped and no address learning will take place. 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 will be broadcast to all the members (excluding the ingress port) of the VLAN. If FID+SA fails,
the FID+SA will be learned.
Examples:
1. VLAN Table Read (read the third entry, at the indirect address offset 0x02)
2. VLAN Table Write (write the seventh entry, at the indirect address offset 0x06)
October 2007
Then
18 – 16
15 – 12
11 – 0
Bit
19
Write to reg. IACR with 0x1402 (set indirect address and trigger a read VLAN table operation)
Read reg. IADR5 (VLAN table bits 19-16)
Read reg. IADR4 (VLAN table bits 15-0)
Write to reg. IADR5 (VLAN table bits 19-16)
Write to reg. IADR4 (VLAN table bits 15-0)
Write to reg. IACR with 0x1406 (set indirect address and trigger a read VLAN table operation)
Default
0x001
111
0x0
1
R/W
R/W
R/W
R/W
RW
Table 14. VLAN Table Format (16 Entries)
Description
Valid
1 = specifies that this entry is valid, the look up result will be used
0 = specifies that this entry is not valid
Membership
Specifies which ports are members of the VLAN. 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. For example: 101
means port 3 and 1 are in this VLAN.
FID
Specifies the Filter ID. The KSZ8842-PMQL/PMBL supports 16 active
VLANs represented by these four bit fields. The FID is the mapped ID. If
802.1Q VLAN is enabled, the look up will be based on FID+DA and
FID+SA.
VID
Specifies the IEEE 802.1Q 12 bits VLAN ID.
108
KSZ8842-PMQL/PMBL
M9999-100207-1.5