KSZ8864RMNI MICREL [Micrel Semiconductor], KSZ8864RMNI Datasheet - Page 39

• Manufacturer Part Number: KSZ8864RMNI
• Description: Integrated 4-Port 10/100 Managed Switch with Two MACs MII or RMII Interfaces
• Manufacturer: MICREL [Micrel Semiconductor]

September 2011
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.
RSTP uses only one type of BPDU called RSTP BPDUs. They are similar to STP Configuration BPDUs with the
exception of a type field set to “version 2” for RSTP and “version 0” for STP, and a flag field carrying additional
information.
Tail Tagging Mode
The Tail Tag is only seen and used by the Port 4 interface, which should be connected to a processor by MAC 4
SW4-MII/RMII interface. The one byte tail tagging is used to indicate the source/destination port in Port 4. Only bit
[31] are used for the destination in the tail tagging byte. Bit 0 is not used. The Tail Tag feature is enabled by setting
register 12 bit 1.
Ingress to Port 4 (Host
Bit [3:1]
0,0,0
0,0,1
0,1,0
1,0,0
1,1,1
Bit [7:4]
0,0,0,0
0,0,0,1
0,0,1,0
0,0,1,1
x, 1,x,x
1, x,x,x
Egress from Port 4 (KSZ8864RMN
Bit [1:0]
0,0
0,1
1,0
1,1
Figure 7. Tail Tag Frame Format
Destination
Normal (Address Look up for destination)
Port 1 (direct forward to port1)
Port 2 (direct forward to port2)
Port 3 (direct forward to port3)
Port 1,2 and 3 (direct forward to port 1,2,3)
Queue 0 is used at destination port
Queue 1 is used at destination port
Queue 2 is used at destination port
Queue 3 is used at destination port
Whatever send packets to specified port in bit[3:1]
Bit[6:0] will be ignored
Source
Reserved
Port 1 (packets from port 1)
Port 2 (packets from port 2)
Port 3 (packets from port 3)
Table 5. Tail Tag Rules
KSZ8864RMN)
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Host )
M9999-092011-1.4