KSZ8895 INFINEON [Infineon Technologies AG], KSZ8895 Datasheet - Page 45

• Manufacturer Part Number: KSZ8895
• Description: Integrated 5-Port 10/100 Managed Ethernet Switch with MII/RMII interface
• Manufacturer: INFINEON [Infineon Technologies AG]

Micrel, Inc.
Tail Tagging Mode
The Tail Tag is only seen and used by the Port 5 interface, which should be connected to a processor by SW5-MII
interface. The one byte tail tagging is used to indicate the source/destination port in Port 5. Only bit [3-0] are used for
the destination in the tail tagging byte. Other bits are not used. The Tail Tag feature is enabled by setting register 12
bit 1.
January 2011
Ingress to Port 5 (Host --> KSZ8895MQ/RQ/FMQ)
Bit [3:0]
0,0,0,0
0,0,0,1
0,0,1,0
0,1,0,0
1,0,0,0
1,1,1,1
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 5 (KSZ8895MQ/RQ/FMQ --> Host)
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 4 (direct forward to Port4)
Port 1, 2,3 and 4 (direct forward to Port 1,2,3,4,)
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[3:0]
Bit[6:0] will be ignored
Source
Port 1 (packets from Port 1)
Port 2 (packets from Port 2)
Port 3 (packets from Port 3)
Port 4 (packets from Port 4)
Table 7. Tail Tag Rules
45
KSZ8895MQ/RQ/FMQ
M9999-012011-1.2