Tackling intracell variability in TLC Flash through tensor product codes

Flash memory is a promising new storage technology. To fully utilize future multi-level cell Flash memories, it is necessary to develop error correction coding schemes attuned to the underlying physical characteristics of Flash. Based on a careful inspection of fine-grained, experimentally-collected error patterns of TLC (three bits per cell) Flash, we propose a mathematical model that captures the intracell variability, which is manifested by certain patterns of bit-errors. Error correction codes are constructed for this model based upon generalized tensor product codes. For fixed levels of redundancy, these codes are shown to exhibit substantially lower bit error rates than existing error correction schemes.