KSZ8864RMN Datasheet, PDF (38/112 Pages) Micrel Semiconductor – Integrated 4-Port 10/100 Managed Switch with Two MACs MII or RMII Interfaces

Micrel, Inc.
KSZ8864RMN
Blocking state: only packets to the processor are forwarded. Learning is disabled.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1"
Software action: the processor should not send any packets to the port(s) in this state. The processor should
program the “Static MAC table” with the entries that it needs to receive (e.g., BPDU packets). The “overriding” bit
should also be set so that the switch will forward those specific packets to the processor. Address learning is
disabled on the port in this state.
Listening state: only packets to and from the processor are forwarded. Learning is disabled.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1.
"Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see the “Tail Tagging Mode” section for
details. Address learning is disabled on the port in this state.
Learning state: only packets to and from the processor are forwarded. Learning is enabled.
Port setting: “transmit enable = 0, receive enable = 0, learning disable = 0.”
Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see the “Tail Tagging Mode” section for
details. Address learning is enabled on the port in this state.
Forwarding state: packets are forwarded and received normally. Learning is enabled.
Port setting: “transmit enable = 1, receive enable = 1, learning disable = 0.”
Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see “Tail Tagging Mode” section for details.
Address learning is enabled on the port in this state.
Rapid Spanning Tree Support
There are three operational states of the Discarding, Learning, and Forwarding assigned to each port for RSTP:
Discarding ports Do not participate in the active topology and Do not learn MAC addresses.
Discarding state: the state includs three states of the disable, blocking and listening of STP.
Port setting: "transmit enable = 0, receive enable = 0, learning disable = 1."
Software action: the processor should not send any packets to the port. The switch may still send specific packets to
the processor (packets that match some entries in the static table with “overriding bit” set) and the processor should
discard those packets. When disable the port’s learning capability (learning disable=’1’), set the register 1 bit5 and
bit4 will flush rapidly with the port related entries in the dynamic MAC table and static MAC table.
Note: processor is connected to Port 4 MAC 4 SW4-MII/RMII interface. Address learning is disabled on the port in
this state.
Ports in Learning states learn MAC addresses, but Do not forward user traffic.
Learning state: only packets to and from the processor are forwarded. Learning is enabled.
Port setting: “transmit enable = 0, receive enable = 0, learning disable = 0.”
Software action: The processor should program the static MAC table with the entries that it needs to receive (e.g.,
BPDU packets). The “overriding” bit should be set so that the switch will forward those specific packets to the
processor. The processor may send packets to the port(s) in this state, see “Tail Tagging Mode” section for details.
Address learning is enabled on the port in this state.
Ports in Forwarding states fully participate in both data forwarding and MAC learning.
Forwarding state: packets are forwarded and received normally. Learning is enabled.
September 2011
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M9999-092011-1.4