A Study on Approximate Computing for Non-volatile Memory-Based Memory Systems

Approximate computing is a technique that emphasizes efficiency and energy conservation over absolute accuracy by permitting some level of error in outcomes. Among several application fields, this paper focuses on a cache-coherence protocol in terms of approximate computing, because as core counts increase. To improve the computational efficiency, cache lines are indicated as ‘approximate’ or ‘precise’. While the existing protocols focus on cache line accuracy, systems using non-volatile memory consider both accuracy and energy consumption. This paper introduces a novel cache coherence protocol that integrates states for approximate values. The simulation results show an 11.2% reduction in data transfers with the middle confidence level.