Abstract: Approaches are presented for adaptively re-compacting data when errors are found during a post-write verify in a non-volatile memory system, such as flash NAND memory. In one example, user data along with corresponding parity data is written into a block of non-volatile memory. After writing in the user data, but prior to writing the corresponding parity data, the user data is checked. For any word lines that fail this post-write verify, the parity data for the block is adjusted to remove the contribution of any failed word lines before this modified parity data is written into the block. The data corresponding to the failed word lines can then be written elsewhere in the memory system.

Abstract: A controller circuit for a non-volatile memory of one or more memory circuits is described. The controller is connectable by a port with the memory circuits through a bus structure and can operate the memory circuits according to one or more threads. The controller includes a command processing section to issue high level commands for execution in the memory circuits and a memory circuit interface module to issue in sequence by the port to the memory circuits a series of instruction derived from the high level commands. A queue manager on the controller derives the series of instructions from the high level commands. When deriving a series of instruction from a set of high level data access commands, the queue manager can modify the timing for the issuance to the memory circuit interface module of memory circuit check status instructions based upon feedback from the memory circuit interface module and the state of earlier instruction in the series.