ROBUST DATA DUPLICATION AND IMPROVED UPDATE METHOD IN A MULTIBIT NON-VOLATILE MEMORY

摘要

In a nonvolatile memory with block management system, critical data such as control data for the block management system is maintained in duplicates. Various methods are described for robustly writing and reading two copies of critical data in multi-state memory. In another aspect of the invention, a preemptive garbage collection on memory block containing control data avoids an undesirable situation where a large number of such memory blocks need be garbage collected at the same time.