KSZ8842-PMBLAM MICREL [Micrel Semiconductor], KSZ8842-PMBLAM Datasheet - Page 26

• Manufacturer Part Number: KSZ8842-PMBLAM
• Description: 2-Port Ethernet Switch with PCI Interface
• Manufacturer: MICREL [Micrel Semiconductor]

Micrel, Inc.
Forwarding
The KSZ8842-PMQL/PMBL forwards packets using the algorithm that is depicted in the following flowcharts. Figure 7
shows stage one of the forwarding algorithm where the search engine looks up the VLAN ID, static table, and dynamic
table for the destination address, and comes up with “port to forward 1” (PTF1). PTF1 is then further modified by
spanning tree, IGMP snooping, port mirroring, and port VLAN processes to come up with “port to forward 2” (PTF2), as
shown in Figure 8. The packet is sent to PTF2.
October 2007
Dynamic MAC Table
Search complete.
Static MAC Table
Search complete.
Get PTF1 from
Get PTF1 from
PTF1 = NULL
Figure 7. Destination Address Lookup Flow Chart, Stage 1
FOUND
FOUND
NO
Search complete.
Dynamic Table
Get PTF1 from
Search Static
VLAN table
VLAN ID
Search
valid?
Table
PTF1
Start
26
FOUND
FOUND
YES
NOT
NOT
- Search VLAN table
- Ingress VLAN filtering
- Discard NPVID check
This search is based on
DA or DA+FID
This search is based on
DA+FID
KSZ8842-PMQL/PMBL
M9999-100207-1.5