PCM-FTL: A write-activity-aware NAND flash memory management scheme for PCM-based embedded systems

Duo Liu, Tianzheng Wang, Yi Wang, Zhiwei Qin, Zili Shao

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

63 Citations (Scopus)


Due to its properties of high density, in-place update, and low standby power, phase change memory (PCM) becomes a promising main memory alternative in embedded systems. On the other hand, NAND flash memory is widely used as a secondary storage and has been integrated into PCM-based embedded systems. Since both NAND flash memory and PCM have limited lifetime, how to effectively manage NAND flash memory in PCM-based embedded systems, while considering the endurance issue is very important. In this paper, we present for the first time a write-activity-aware NAND flash memory management scheme, called PCMFTL, to effectively manage NAND flash memory and enhance the endurance of PCM-based embedded systems. The basic idea is to preserve each bit in flash mapping table, which is stored in PCM, from being inverted frequently, i.e., we focus on minimizing the number of bit flips in a PCM cell when updating the flash mapping table. PCM-FTL employs a two-level mapping mechanism, which not only focuses on minimizing the write activities of PCM but also considers the access behavior of I/O requests. We evaluate PCM-FTL using a variety of realistic I/O traces. Experimental results show that the proposed technique can achieve an average reduction of 93.10% and a maximum reduction of 98.98% in the maximum number of bit flips for a PCM-based embedded system with 1GB NAND flash memory. We hope this work can serve as a first step towards the design of write-activity-aware FTL for the PCM-based embedded systems via simple and feasible modifications.
Original languageEnglish
Title of host publicationProceedings - 2011 32nd IEEE Real-Time Systems Symposium, RTSS 2011
Number of pages10
Publication statusPublished - 1 Dec 2011
Event2011 32nd IEEE Real-Time Systems Symposium, RTSS 2011 - Vienna, Austria
Duration: 29 Nov 20112 Dec 2011


Conference2011 32nd IEEE Real-Time Systems Symposium, RTSS 2011


  • Endurance
  • Flash translation layer
  • NAND flash memory
  • Phase change memory

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Computer Networks and Communications

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