A queue monitoring system and method determines when one or more transmit
queues have reached a state that requires action by the host processing
device, without the need for periodic polling of transmit status or
excessive interrupt servicing. The queue monitoring implements an
interrupt mechanism that generates an interrupt if one or more of the
transmit queues has gone from a non-empty state to an empty state, and
remained in the empty state for a (programmable) period of time. The
combination of queue status checking (when adding new transmit data) with
the queue monitoring interrupt mechanism removes the need for periodic
polling of queue status and handling of interrupts generation on the
completed transmission of data from one or more transmit buffer.