Real-Time Communication Analysis for Networks-on-Chip with Backpressure

Sebastian Tobuschata and Rolf Ernstb
Institute of Computer and Network Engineering, Technische Universität Braunschweig, Germany.


Networks-on-Chip (NoCs) for safety-critical domains require formal guarantees for the worst-case behavior of all real-time senders. The majority of existing analysis approaches is capable of providing such guarantees only under the assumption that the queues in the routers never overflow, i.e., that no backpressure occurs. This leads to overly pessimistic guarantees or unfulfilled design requirements in many setups using commercially available NoCs where buffer space is limited. Therefore, we propose an alternative analysis methodology providing formal timing guarantees for packet latencies also in a NoC where backpressure occurs. The analysis allows exploiting the behavior of individual traffic streams to determine safe upper bounds on the latency of individual packets. The correctness of the analysis is evaluated experimentally through comparison with simulation results.

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