| dc.description.abstract | Non-volatile memories are an emerging storage technology with wide applica-
tions in many important areas. This study focuses on new storage techniques for
flash memories and phase-change memories. Flash memories are currently the most
widely used type of non-volatile memory, and phase-change memories (PCMs) are
the most promising candidate for the next-generation non-volatile memories. Like
magnetic recording and optical recording, flash memories and PCMs have their own
distinct properties, which introduce very interesting data storage problems. They
include error correction, cell programming and other coding problems that affect the
reliability and efficiency of data storage. Solutions to these problems can signifi-
cantly improve the longevity and performance of the storage systems based on flash
memories and PCMs.
In this work, we study several new techniques for data storage in flash memories
and PCMs. First, we study new types of error-correcting codes for flash memories –
called error scrubbing codes –that correct errors by only increasing cell levels. Error
scrubbing codes can correct errors without the costly block erasure operations, and we
show how they can outperform conventional error-correcting codes. Next, we study
the programming strategies for flash memory cells, and present an adaptive algorithm
that optimizes the expected precision of cell programming. We then study data storage in PCMs, where thermal interference is a major challenge for data reliability.
We present two new coding techniques that reduce thermal interference, and study
their storage capacities and code constructions. | en |
