Exploiting Approximate Computing for Low-Cost Fault Tolerant Architectures

This work investigates how the approximate computing paradigm can be exploited to provide low-cost fault tolerant architectures. In particular, we focus on the implementation of Approximate Triple Modular Redundancy (ATMR) designs using the precision reduction technique. The proposed method is applied to two benchmarks and a multitude of ATMR designs with different degrees of approximation. The benchmarks are implemented on a Xilinx Zynq-7000 APSoC FPGA through high-level synthesis and evaluated concerning area usage and the inaccuracy caused by approximation. Fault injection experiments are performed by flipping bits of the FPGA configuration bitstream. Results show that the proposed approximation method can decrease the DSP usage of the hardware implementation up to 80% and the number of sensitive configuration bits up to 75% while maintaining an accuracy of more than 99.96%.