Automated Design and Usage of the Fault-Tolerant Dynamic Partial Reconfiguration Controller for FPGAs

Fault-Tolerant System Design, Electronic Design Automation, Dynamic Partial Reconfiguration, Redundancy Allocation and Insertion, FPGA, VHDL

This article presents a new design automation method for Fault-Tolerant (FT) systems implemented on dynamically reconfigurable Field Programmable Gate Arrays (FPGAs). The method aims at minimizing the human interactions needed to incorporate FT mechanisms into an existing system. It starts with a source code of an original unhardened circuit. It continues by automated manipulation of the source code, algorithmic strategic selection of suitable FT techniques, design space exploration of candidate FT implementations, and selection of the resulting implementation. The method also includes efficient evaluation of achieved FT parameters performed on the target HW. As a novel approach working on the level of HW description languages is employed, the code modification is separated, which differentiates our method from others. The case study utilizing this method targets the design of an experimental FT dynamic partial reconfiguration controller for an FPGA. This controller is helpful for the restoration of faulty components due to a single-event upset on an FPGA. We used the method to generate a set of Pareto-optimal controllers concerning the design's Mean Time to Failure (MTTF) parameter, power consumption, and size. Then, the FT controller is connected to several benchmark circuits, and the reliability parameters are evaluated at the entire system level. Our results show that by replacing the standard reconfigurable controller with our automatically-designed FT controller for one specific benchmark, the design size increased by 20.1%, and MTTF increased by 11.7%. However, the efficiency is highly dependent on the target system size, MTTF, and circuit functionality. We also estimate that a complex system defined by half a million configuration bits would improve MTTF by more than 50%.