Magnetic random-access memory (MRAM) is a promising memory technology due to its high density, non-volatility, and high endurance. However, achieving high memory fidelity incurs significant write-energy costs, which should be reduced for large-scale deployment of MRAMs. In this paper, we formulate an optimization problem for maximizing the memory fidelity given energy constraints, and propose a biconvex optimization approach to solve it. The basic idea is to allocate non-uniform write pulses depending on the importance of each bit position. The fidelity measure we consider is minimum mean squared error (MSE), for which we propose an iterative water-filling algorithm. Although the iterative algorithm does not guarantee global optimality, we can choose a proper starting point that decreases the MSE exponentially and guarantees fast convergence. For an 8-bit accessed word, the proposed algorithm reduces the MSE by a factor of 21.
@article{arxiv.2001.03803,
title = {Optimizing the Write Fidelity of MRAMs},
author = {Yongjune Kim and Yoocharn Jeon and Cyril Guyot and Yuval Cassuto},
journal= {arXiv preprint arXiv:2001.03803},
year = {2020}
}