Transaction Monitoring in Networks on Chip: The On-Chip Run-Time Perspective

Networks-on-chip (NoC) are a scalable interconnect solution to multiprocessor systems on chip (MPSoC). NoCs transport data in packets which are fragments of transactions, such as read and write actions of IPs. For debug purposes, reconstructing transactions at run-time is essential. Run-time analysis of the NoC behavior at transaction level makes the complete MPSoC easier to understand. We present a NoC analyzer able to monitor NoC transactions at run-time. The proposed hardware transaction monitor is able to reconstruct on-chip, at run-time, NoC transactions from bit-level intercepted router link communication. Four NoC analyzer modes are detailed raising the abstraction level gradually from physical raw to logical connection-based, transaction-based and abstract transaction event-based. Each mode is analyzed for area and bandwidth in an experimental setup based on several AEligthereal NoC designs. A transaction monitor has an area cost of 0.026 mm² in a 0.13 mum CMOS technology, and for several MPEG/audio case studies, the entire monitoring system adds an average of 5% to the NoC area. We show the versatility of our NoC analyzer by run-time monitoring user connections and the Configuration Master IP in the NoC.