A PV aware data placement scheme for read performance improvement on LDPC based flash memory: work-in-progress

Qiao Li, Liang Shi, Yejia Di, Yajuan Du, Kaijie Wu, Chun Jason Xue, Qingfeng Zhuge, Edwin Hsing-Mean Sha

Abstract: This paper proposes to improve read performance of LDPC based flash memory by exploiting process variation (PV). The work includes three parts. First, a block grouping approach is proposed to classify the flash blocks based on their reliability. Second, based on the grouping approach, a read data placement scheme is proposed, which is designed to place read-hot data on flash blocks with high reliability. However, simply placing read-hot data to high reliable blocks conflicts with recent PV-aware wear leveling schemes. In the third part of the work, a grouping partition scheme is proposed to limit the number of high reliable blocks for read-hot data. In this case, read performance can be well improved with little impact on the lifetime improvement.