Scalable AXI4 Transaction Monitoring for Mixed-Criticality SoCs: From Phase-Level Precision to ID-Level Efficiency
Scalable AXI4 Transaction Monitoring for Mixed-Criticality SoCs: From Phase-Level Precision to ID-Level Efficiency
Abstract
Mixed-criticality systems-on-chip (SoCs) with onchip interconnects based on the Advanced eXtensible Interface 4 (AXI4) open standard protocol lack a protocol-level timeout mechanism, exposing systems to deadlocks and missed real-time deadlines when subordinate devices or managers fail or stall due to hardware faults, radiation-induced upsets, or software errors. This work presents a configurable hardware intellectual property (IP), nonintrusive in fault-free operation, that detects AXI4 protocol violations and timing faults at runtime and restores interconnect liveness through a cut-and-drain isolation mechanism. To address the fundamental tradeoff between monitoring granularity and area cost, we introduce three designs at decreasing monitoring granularity: phase-level tracking (PLT), which provides cycle-accurate fault localization across individual protocol phases; channel-level tracking (CLT), which coalesces per-phase monitors into channel-level supervision; and ID-level tracking (ILT), which achieves sublinear area scaling by monitoring only per-ID transaction boundaries. Synthesized in GlobalFoundries 12-nm technology, CLT reduces area by 36.7% relative to PLT while preserving worst case detection bounds at a minimal detection latency overhead, whereas ILT achieves an 89.2% area reduction suitable for tightly constrained deployments at the cost of a 3.7× higher median detection latency with coarser fault localization. Fault injection campaigns on a RISC-V SoC across 1.2 million scenarios confirm that no fault manifesting as an AXI4 protocol or liveness violation escaped detection, with observed detection latencies consistently bounded by theoretical worst case predictions.
Thank you for visiting this project page. Register this project to explore its novelty and implementation support.
