PERFECT ERROR COMPENSATION VIA ALGORITHMIC ERROR CANCELLATION

This paper presents a novel statistical error compensation (SEC) technique - algorithmic error cancellation (AEC) for designing robust and energy-efficient signal processing and machine learning kernels on scaled process technologies. AEC exhibits a perfect error compensation (PEC) property, i.e., it is able to achieve a post-compensation error rate equal to zero. AEC generates a maximum likelihood (ML) estimate of the hardware error and employs it for error cancellation. AEC is applied to a voltage overscaled 45-tap, 45nm CMOS finite impulse response (FIR) filter employed in a EEG seizure detection system. AEC is shown to perfectly compensate for errors in the main FIR block and its reduced precision replica when they make errors at a rate of up to 73% and 98%, respectively. The AEC-based FIR is compared with an uncompensated architecture, and a fast architecture. AEC's error compensation capability enables it to achieve a 31.5% (at same supply voltage) and 19.7% (at same energy) speed-up over the uncompensated architecture, and a 8.9% speed-up over a fast architecture at the same energy consumption. At f(clk) = 452.3MHz, AEC results in a 27.7% and 12.4% energy savings over the uncompensated and fast architectures, respectively.