MEASURING MEMORY WEAR AND DATA RETENTION INDIVIDUALLY BASED ON CELL VOLTAGE DISTRIBUTIONS

摘要

A memory system or flash card may include a mechanism for memory cell measurement and analysis that independently measures/predicts memory wear/endurance, data retention (DR), and/or remaining margin. These effects may be independently quantified by analyzing the state distributions of the individual voltage levels of the cells. In particular, a histogram of cell voltage distributions of the memory cells can be analyzed to identify signatures for certain effects (e.g. wear, DR, margin, etc.). Those measurements may be used for block cycling, data loss prediction, or adjustments to memory parameters. Pre-emptive action at the appropriate time based on the measurements may lead to improved memory management and data management. That action may include calculating the remaining useful life of data stored in memory, cycling blocks, predicting data loss, trade-off or dynamic adjustments of memory parameters.