A Non-Intrusive Isolation Approach for Soft Cores

Cost effective SOC test strongly hinges on parallel, independent test of SOC cores, which can only be ensured through proper core isolation techniques. While a core isolation mechanism can provide controllability and observability at the core I/O interface, its implementation may have various implications on area, functional timing, test time and data volume, and at-speed coverage on the core interface. This paper proposed a non-intrusive core isolation technique that is based on the utilization of existing core registers for isolating the core. The authors provide a core register partitioning algorithm that is capable of identifying the core interface registers, and of robustly isolating a core, resulting in a computationally efficient core isolation implementation that is area and performance efficient at the same time. The proposed isolation technique also ensures minimal test time increase and no at-speed coverage loss on the core interface, offering an elegant solution for soft cores, and thus enabling significant SOC test cost reductions