Automated synthesis of mixed-signal ML inference hardware under accuracy constraints

Due to the inherent error-tolerance of machine learning (ML) algorithms, many parts of the inference computation can be performed with adequate accuracy and low power under relatively low precision. Early approaches have used digital approximate computing methods to explore this space. Recent approaches using analog-based operations achieve power-efficient computation at moderate precision. This work proposes a mixed-signal optimization (MiSO) approach that optimally blends analog and digital computation for ML inference. Based on accuracy and power models, an integer linear programming formulation is used to optimize design metrics of analog/digital implementations. The efficacy of the method is demonstrated on multiple ML architectures.