Data Sheet

Inline Functions—Ethernet Controller I210
315
7.2.7.4 Mapping User Priorities to Queues
While in Qav mode each active queue in the I210 represents a single or multiple User Priorities, The
queue priority is pre-assigned such that queue0 has the highest priority and priorities decrease through
queue1, queue2 and queue3 has the lowest priority.
Software is responsible to map the proper Ethernet traffic using the appropriate stream priority to its
hardware destination queue according to the relevant priority it is assigned.
Traffic priority can be assigned according to the VLAN priority field in the VLAN tag.
Figure 7-11. Transmit Architecture Qav Mode
Queue 0 Queue 1
Queue 2 Queue 3
Head
Tail
Head
Tail
Head
Tail
Head
Tail
Fetch
Arbiter
Read
Request
Packet
Buffers
Transmit
MAC
Launch
Arbiter
Read
Completion
DMA
Clock
Clock
Manageability
Traffic
Round
Robin
Transmit
Data Buffers
in host
Memory
Packet
Buffers
Packet
Buffer 0