Temporal Partitioning in Mixed-Criticality NoCs Using Timely Blocking
Hamidreza Ahmadian, Roman Obermaisser · 2017
The ongoing trend to integrate multiple functions with different criticalities on a single platform calls for a robust on-chip communication infrastructure in which subsystems of different criticalities can coexist and interact. A fundamental challenge in the design of such systems is to prevent low-critical subsystems from interfering with safety-critical subsystems, while providing the demanded performance for low-critical subsystems. This challenge is addressed by different technical approaches for the arbitration of the resource requests, in particular when it comes to the on-chip communication. Preemption can be used to interrupt the ongoing transmission of a low-critical message in favor of the resource request by a safe-critical subsystem. Shuffling is used as an alternative to preemption and uses a priority-based arbitration for the resource requests. This approach is used often in NoCs and interrupting the ongoing transmission at the cost of a certain effect of low-critical subsystem on safety-critical one. This paper introduces a third approach in NoCs that provides temporal partitioning of the resources by maintaining guarding windows at different levels. We describe how chip-wide segregation between the communication channels of different subsystems eliminates the interference for safety-critical subsystems and assures bounded interferences for low-critical subsystems.