2016/05/17 by Evyatar Hemo, Hemo, Evyatar, Yuval Cassuto +1
Computer Science · Engineering · #Advanced Data Storage Technologies #Cellular Automata and Applications #FOS: Computer and information sciences #Information Theory (cs.IT) #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.1605.05281
openalex publication_date 2016/05/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In recent years, due to the spread of multi-level non-volatile memories\n(NVM), q-ary write-once memories (WOM) codes have been extensively studied.\nBy using WOM codes, it is possible to rewrite NVMs t times before erasing the\ncells. The use of WOM codes enables to improve the performance of the storage\ndevice, however, it may also increase errors caused by inter-cell interference\n(ICI). This work presents WOM codes that restrict the imbalance between code\nsymbols throughout the write sequence, hence decreasing ICI. We first specify\nthe imbalance model as a bound d on the difference between codeword levels.\nThen a 2-cell code construction for general q and input size is proposed.\nAn upper bound on the write count is also derived, showing the optimality of\nthe proposed construction. In addition to direct WOM constructions, we derive\nclosed-form optimal write regions for codes constructed with continuous\nlattices. On the coding side, the proposed codes are shown to be competitive\nwith known codes not adhering to the bounded imbalance constraint. On the\nmemory side, we show how the codes can be deployed within flash wordlines, and\nquantify their BER advantage using accepted ICI models.\n