Method and apparatus for fast acknowledgement and efficient servicing of interrupt sources coupled to high latency paths

摘要

A system and technique provides fast acknowledgement and servicing of interrupt sources coupled to a high latency path of an intermediate node of a computer network. An external device coupled to the high latency path is provided with a separate interrupt signal for each type of interrupt supported by a processor of the intermediate node. Each interrupt signal is directly fed to an interrupt multiplexing device over a first low latency path. The multiplexing device is accessible to the processor through a second low latency path. The external device asserts an interrupt by "pulsing" an appropriate interrupt signal to the multiplexing device. The multiplexing device maintains a current counter for each interrupt signal and increments that counter every time an interrupt pulse is detected. In addition to the counter, the multiplexing device maintains a status bit for each interrupt.