SHF: Small: Some Error Correcting Codes for Computer Systems

Oregon State University, Corvallis OR

Investigators

Abstract

Error control codes play a major role in achieving high reliable operations of modern computer systems, DVDs, cameras, etc. In this project new classes of error correcting codes suitable for high density flash memories are to be developed. The market revenue of flash memories is estimated to be $100B per year. The PI has close collaboration with leading Flash memory industry (Micron). While this enables development of error correcting codes specifically in the practical context of applications, the results of this research will not only be easily transitioned to industry, it will also train students, postdocs and future industry researchers via lectures, seminars and course development at the PIs institution. In this project, multi-level flash, in which each cell can have 4 or 8 voltage levels, will be considered. Experiments indicate that the bit error rate of flash memory worsens as the Program/Erasure count increases. In addition, it is observed that most of the errors are of limited magnitude and of decreasing type. Study of error statistics of error characteristics justify that the L1 distance codes are more suitable to overcome errors in flash memories. New classes of L1 distance codes are to be developed using the concepts of elementary symmetric functions. The project will also consider the design of error correcting codes for insertion and deletion of repeated symbols in high speed data bus and communication systems. Furthermore, the theory and codes to be developed for flash memories can potentially be extended to design efficient high-ordered-spectral-null codes for optical discs and magnetic memories.