KSZ8873FLLI Micrel Inc, KSZ8873FLLI Datasheet - Page 36

• Manufacturer Part Number: KSZ8873FLLI
• Description: IC ETHERNET SWITCH 3PORT 64LQFP
• Manufacturer: Micrel Inc

Specifications of KSZ8873FLLI

• Controller Type: Ethernet Switch Controller
• Interface: MII
• Voltage - Supply: 1.8V, 2.5V, 3.3V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed
• Other names: 576-3632; KSZ8873FLLI

Micrel, Inc.
IGMP Support
For Internet Group Management Protocol (IGMP) support in layer 2, the KSZ8873MLL/FLL/RLL provides two
components:
IGMP Snooping
The KSZ8873MLL/FLL/RLL traps IGMP packets and forwards them only to the processor (port 3). The IGMP packets are
identified as IP packets (either Ethernet IP packets, or IEEE 802.3 SNAP IP packets) with IP version = 0x4 and protocol
version number = 0x2.
Multicast Address Insertion in the Static MAC Table
Once the multicast address is programmed in the Static MAC Table, the multicast session is trimmed to the subscribed
ports, instead of broadcasting to all ports.
To enable IGMP support, set register 5 bit [6] to ‘1’. Also, Tail Tagging Mode needs to be enabled, so that the processor
knows which port the IGMP packet was received on. This is achieved by setting both register 3 bit [6] and register 48 bit
[2] to ‘1’.
Port Mirroring Support
KSZ8873MLL/FLL/RLL supports “Port Mirroring” comprehensively as:
September 2009
“receive only” mirror on a port
All the packets received on the port are mirrored on the sniffer port. For example, port 1 is programmed to be
“receive sniff” and port 3 is programmed to be the “sniffer port”. A packet received on port 1 is destined to port 2
after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 2 and port 3. The
KSZ8873MLL/FLL/RLL can optionally even forward “bad” received packets to the “sniffer port”.
“transmit only” mirror on a port
All the packets transmitted on the port are mirrored on the sniffer port. For example, port 1 is programmed to be
“transmit sniff” and port 3 is programmed to be the “sniffer port”. A packet received on port 2 is destined to port 1
after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 1 and port 3.
“receive and transmit” mirror on two ports
All the packets received on port A and transmitted on port B are mirrored on the sniffer port. To turn on the “AND”
feature, set register 5 bit [0] to ‘1’. For example, port 1 is programmed to be “receive sniff”, port 2 is programmed
to be “transmit sniff”, and port 3 is programmed to be the “sniffer port”. A packet received on port 1 is destined to
port 2 after the internal lookup. The KSZ8873MLL/FLL/RLL forwards the packet to both port 2 and port 3.
Ingress to Port 3 (Host -> KSZ8873MML)
Bit [1,0]
0,0
0,1
1,0
1,1
Bit [3,2]
0,0
0,1
1,0
1,1
Egress from Port 3 (KSZ8873MML->Host)
Bit [0]
0
1
Figure 8. Tail Tag Rules
Destination Port
Normal (Address Look up)
Port 1
Port 2
Port 1 and 2
Frame Priority
Priority 0
Priority 1
Priority 2
Priority 3
Source Port
Port 1
Port 2
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KSZ8873MLL/FLL/RLL
M9999-092309-1.2