Scalable AXI4 Transaction Monitoring for Mixed-Criticality SoCs: From Phase-Level Precision to ID-Level Efficiency

2026-08-31

AI Summary

为了解决AXI4协议缺乏超时机制导致的死锁问题，本文提出了一种可配置硬件IP，通过三种不同粒度的设计（PLT、CLT和ILT）来监测并恢复互联活动。

Abstract

Mixed-criticality Systems-on-Chip (SoCs) with on-chip interconnects based on the 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), non-intrusive 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 trade-off between monitoring granularity and area cost, we introduce three designs at decreasing monitoring granularity: Phase-Level Track-ing (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 sub-linear 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 3.7x 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.

Problem

• AXI4
• mixed-criticality SoCs
• timeout mechanism
• deadlocks
• real-time deadlines

Innovation

• Scalable AXI4 Monitoring
• Mixed-Criticality SoCs
• Phase-Level Tracking (PLT)
• Channel-Level Tracking (CLT)
• ID-Level Tracking (ILT)