Figure 6.7, Datasheet – SMSC LAN9312 User Manual
Page 73
High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312
73
Revision 1.4 (08-19-08)
DATASHEET
The ingress flow calculation is based on the packet type and the device configuration as shown in
.
Figure 6.7 Switch Engine Ingress Flow Priority Selection
Figure 6.8 Switch Engine Ingress Flow Priority Calculation
Programmable
DIFFSERV Table
Programmable
Port Default
Table
3b
3b
2b
6b
3b
Packet is Tagged
VL Higher Priority
Packet is IPv 4
Packet is IP
Use Precedence
Use IP
IPv4(TOS)
IPv6(TC)
flow priority
Source Port
VLAN Priority
IPv4 Precedence
3b
3b
VLAN Enable
Priority
Calculation
Packet is from Host
Flow Priority =
VLAN Priority
N
Packet is IPv 4/v6
& Use IP
Flow Priority =
IP Precedence
Y
Use Precedence
Y
N
Flow Priority =
DIFFSERV[TC]
N
Y
Vlan Enable &
Packet is
Tagged
Y
N
N
Flow Priority =
Default Priority[Source
Port]
Packet is IPv 4
Flow Priority =
DIFFSERV[TOS]
Y
N
Get Flow Priority Done
VL Higher
Priority
Vlan Enable &
Packet is
Tagged
N
Y
Get Flow Priority
Packet from Host
Y