Error characterization and coding schemes for flash memories

Abstract

In this work, we use an extensive empirical database of errors induced by write, read, and erase operations to develop a comprehensive understanding of the error behavior of flash memories. Error characterization of MLC and SLC flash is given on the block, page, and bit level. Based on our error characterization in MLC flash, we propose an error-correcting scheme which outperforms the conventional BCH code. We compare several schemes which use an MLC block as an SLC block. Finally, an implementation of two-write WOM-codes in SLC flash is given as well as the BER for the first and second write.