An event-based monitoring service for networks on chip

Networks on chip (NoCs) are a scalable interconnect solution for large scale multiprocessor systems on chip (SoCs). However, little attention has been paid so far to the monitoring and debugging support for NoC-based systems. We propose a generic on-line event-based NoC monitoring service, based on hardware probes attached to NoC components. The proposed monitoring service offers run-time observability of NoC behavior and supports system-level and application debugging. The defined service can be accessed and configured at run-time from any network interface port. We present a probe architecture for the monitoring service, together with its associated programming model and traffic management strategies. We prove the feasibility of our approach via a prototype implementation for the Æthereal NoC. The additional monitoring traffic is low; typical monitoring connection configuration for a NoC-based SoC application needs only 4.8KB/s, which is 6 orders of magnitude lower than the 2GB/s per link raw bandwidth offered by theÆthereal NoC.