Abstract: A non-volatile memory is constituted from a set of memory planes, each having its own set of read/write circuits so that the memory planes can operate in parallel. The memory is further organized into erasable blocks, each for storing a logical group of logical units of data. In updating a logical unit, all versions of a logical unit are maintained in the same plane as the original. Preferably, all versions of a logical unit are aligned within a plane so that they are all serviced by the same set of sensing circuits. In a subsequent garbage collection operation, the latest version of the logical unit need not be retrieved from a different plane or a different set of sensing circuits, otherwise resulting in reduced performance. In one embodiment, any gaps left after alignment are padded by copying latest versions of logical units in sequential order thereto.

Abstract: In a nonvolatile memory with block management system that supports update blocks with non-sequential logical units, an index of the logical units in a non-sequential update block is buffered in RAM and stored periodically into the non-volatile memory. In one embodiment, the index is stored in a block dedicated for storing indices. In another embodiment, the index is stored in the update block itself. In yet another embodiment, the index is stored in the header of each logical unit. In another aspect, the logical units written after the last index update but before the next have their indexing information stored in the header of each logical unit. In this way, after a power outage, the location of recently written logical units can be determined without having to perform a scanning during initialization. In yet another aspect, a block is managed as partially sequential and partially non-sequential, directed to more than one logical subgroup.

Abstract: The present invention presents techniques for the linking of physical blocks of a non-volatile memory into composite logical structures or “metablocks”. After determining an initial linking of good physical blocks into metablocks, a record of the linking is maintained in the non-volatile memory where it can be readily accessed when needed. In one set of embodiments, the initially linking is deterministically formed according to an algorithm and can be optimized according to the pattern of any bad blocks in the memory. As additional bad blocks arise, the linking is updated using by replacing the bad blocks in a linking with good blocks, preferably in the same sub-array of the memory as the block that they are replacing.

Abstract: A non-volatile memory system is organized in physical groups of physical memory locations. Each physical group (metablock) is erasable as a unit and can be used to store a logical group of data. A memory management system allows for update of a logical group of data by allocating a metablock dedicated to recording the update data of the logical group. The update metablock records update data in the order received and has no restriction on whether the recording is in the correct logical order as originally stored (sequential) or not (chaotic). Eventually the update metablock is closed to further recording. One of several processes will take place, but will ultimately end up with a fully filled metablock in the correct order which replaces the original metablock. In the chaotic case, directory data is maintained in the non-volatile memory in a manner that is conducive to frequent updates. The system supports multiple logical groups being updated concurrently.

Abstract: According to an embodiment of the present invention, there is provided a method and apparatus for use in a memory system having a non-volatile memory and a controller for limiting the number of non-volatile memory arrays from a plurality of available arrays accessed at one time, wherein the method comprises implementing a pipelining sequence for transferring data to and from the non-volatile memory arrays and limiting the number of active arrays operating at one time, the arrangement being such that the controller waits for the at least one of the arrays to complete before initiating the transfer to and from a further array.