KS8842-32MQL Micrel Inc, KS8842-32MQL Datasheet - Page 33

• Manufacturer Part Number: KS8842-32MQL
• Description: IC SWITCH 10/100 32BIT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KS8842-32MQL

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• 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
• 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 Supply Voltage (max): 3.5V
• Operating Supply Voltage (min): 3.1V
• Operating Temperature Classification: Commercial
• Data Rate: 100Mbps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: KS8842-PMQL-EVAL - EVAL KIT EXPERIMENTAL KS8842KS8842-16MQL-EVAL - EVAL KIT EXPERIMENTAL KS8842
• Lead Free Status / RoHS Status: Not Compliant, Lead free / RoHS Compliant
• Other names: 576-1459

Forwarding
The KSZ8842M forwards packets using the algorithm that is depicted in the following flowcharts. Figure 10 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 11.
The packet is sent to PTF2.
Micrel, Inc.
October 2007
Figure 10. Destination Address Lookup Flow Chart in Stage One
Dynamic MAC Table
Search complete.
Static MAC Table
Search complete.
Get PTF1 from
Get PTF1 from
PTF1 = NULL
FOUND
FOUND
NO
33
Search complete.
Dynamic Table
Get PTF1 from
Search Static
VLAN table
VLAN ID
Search
valid?
Table
PTF1
Start
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
KSZ8842-16/32 MQL/MVL/MVLI/MBL
M9999-102207-1.9