High-Precision Close-to-Analog Programming of PCM Cells as Devices for AiMC Edge-AI

One of the most appealing characteristics of Phase-Change Memory (PCM) technology is the ability to store analog quantities as conductances. To fruitfully exploit this feature in Analog in-Memory Computing (AiMC) applications, highprecision programming algorithms are required. In this paper, a method to reach a fairly arbitrary number of analog levels in PCM cells is proposed. The algorithm has been validated on an AiMC prototype, designed and fabricated using a $28-\text{nm}$ FD-SOI process by STMicroelectronics to compute $512 \times 512$ signed Matrix-Vector Multiplications (MVMs), achieving an Equivalent Number of Bits (ENOB) of 10.55, which improves state-of-theart weights programming accuracy for PCM-based hardware accelerators.