Data Sheet

Ethernet Controller I210 —Inline Functions
330
on the PCIe interface until the EITR counter assigned to that EICR bit has counted down to zero. As
soon as the interrupt is issued, the EITR counter is reloaded with its initial value and the process
repeats again. The interrupt flow should follow Figure 7-15.
EITR is designed to guarantee the total number of interrupts per second so for cases where the I210 is
connected to a network with low traffic load, if the EITR counter counted down to zero and no interrupt
event has happened, then the EITR counter is not re-armed but stays at zero. Thus, the next interrupt
event triggers an interrupt immediately. That scenario is illustrated as Case B that follows.
Figure 7-15. Interrupt Throttle Flow Diagram
Start count
down
A
ssert Interrupt
Counte
r
=
0
?
Load counter
with interval
Yes
Yes
Interrupt
active
?
Yes
No
Counte
r
written to
0
No