A Write-friendly Arithmetic Coding Scheme for Achieving Energy-Efficient Non-Volatile Memory Systems

In the era of the Internet of Things (IoT), wearable IoT devices become popular and closely related to our life. Most of these devices are based on the embedded systems that have to operate on limited energy resources, such as batteries or energy harvesters. Therefore, energy efficiency is one of the critical issues for these devices. To relieve the energy consumption by reducing the total accesses on memory and storage layers, the technologies of storage-class memory (SCM) and data compression techniques are applied to eliminate the data movements and squeeze the data size, respectively. However, the information gap between them hinders the cooperation among the two techniques for achieving further optimizations on minimizing energy consumption. This work proposes a write-friendly arithmetic coding with joint managing both techniques to achieve energy-efficient non-volatile memory (NVM) systems. In particular, the concept of "ignorable bits" is introduced to further skip the write operations while storing the compressed data into SCM devices. The proposed design was evaluated by a series of intensive experiments, and the results are encouraging.