Self-healing reconfigurable logic using autonomous group testing

A self-healing, self-organizing evolvable hardware system is developed using SRAM-based reconfigurable Field Programmable Gate Arrays (FPGAs) and group testing principles. It employs adaptive group testing techniques to autonomously maintain resource viability information as an organic means of transient and permanent fault resolution. Reconfigurability of the SRAM-based FPGA is leveraged to identify logic resource faults which are successively excluded by group testing using alternate device configurations. This simplifies the system architect’s role to definition of functionality using a high-level Hardware Description Language (HDL) and system-level performance versus availability operating point. System availability, throughput, and mean time to isolate faults are monitored and maintained using an Observer-Controller model. Dedicated test vectors are unnecessary as the algorithm operates on the output response produced for real-time operational inputs. Results are demonstrated using a Data Encryption Standard (DES) core that occupies approximately 305 FPGA slices on a Xilinx Virtex-II Pro FPGA. With a single simulated stuck-at-fault, the system identifies a completely validated replacement configuration within three to five positive tests. Results also include approaches for optimizing population size, resource redundancy, and availability. The approach demonstrates a readily-implemented yet robust organic hardware application framework featuring a high degree of autonomous self-control.