Coping with Obsolescence of Processor Cores in Critical Applications

Critical applications are more and more relying on electronic components to provide the services they are designed for. The obsolescence of such electronic components has already been recognized as a critical issue that must be properly addressed. Among the different possibilities, FPGA-based emulation of obsolete digital components seems particularly interesting. This paper proposes an automatic approach for customizing the processor cores before they are implemented on the FPGA of choice, by removing the unnecessary instructions. The benefits stemming from this approach are cost savings thanks to the possibility of adopting smaller, less expensive, FPGA devices, the possibility of integrating both the processor and its companion chip on the same FPGA device, and the possibility of adopting hardware redundancy without incurring in high overheads. The approach has been evaluated on a case study, showing that a customized and hardened processor obtained from our design flow requires the nearly the same area of the original, un-hardened, processor.