System and method for rescheduling host and maintenance operations in a non-volatile memory

A method of managing data comprising:

• performing, in a non-volatile memory system having a non-volatile memory with a plurality of layers and a controller in communication with the non-volatile memory, each of the plurality of layers having a different bit-per-cell data capacity, the following steps:
• selecting a fixed plurality of previously programmed blocks in in the non-volatile memory for executing a balance cycle of maintenance operations;
• determining a balance cycle interleave ratio of host data writes to maintenance writes based on a total amount of valid data in the fixed plurality of previously programmed blocks;
• initiating a maintenance operation on a first block of the fixed plurality of previously programmed blocks using the determined balance cycle interleave ratio;
• after initiating the maintenance operation, and in response to reaching a predetermined scheduling point in the balance cycle, the non-volatile memory system determining whether to substitute a different previously programmed block for one of the fixed plurality of previously programmed blocks based on a change in an amount of valid data in one of the fixed plurality of previously programmed blocks or in the different previously programmed block;
• and
• substituting the different previously programmed block for one of the fixed plurality of previously programmed blocks in response to the change in the amount of valid data.

A memory system, comprising:

• at least one non-volatile memory having a plurality of layers, each of the plurality of layers having a different bit-per-cell data capacity and a plurality of memory blocks;
• data management circuitry in communication with the non-volatile memory, the data management circuitry configured to select a fixed plurality of previously programmed blocks in one of the plurality of layers for a balance cycle of maintenance operations, the balance cycle comprising a set of maintenance cycles for the fixed plurality of previously programmed blocks;
• and
• program interleave circuitry configured to:
• determine a balance cycle interleave ratio of host data writes to maintenance writes based on a total amount of valid data in the fixed plurality of previously programmed blocks, wherein the balance cycle of maintenance operations comprises operations to move all valid data from each of the fixed plurality of previously programmed blocks selected for the balance cycle interleaved with writing an amount of host data equal to an amount of obsolete data in the plurality of previously programmed blocks such that an amount of free space created by moving the valid data from the fixed plurality of previously programmed blocks balances an amount of free space consumed by host writes during the balance cycle;
• upon determining the balance cycle interleave ratio, initiate a maintenance operation on a first block of the fixed plurality of previously programmed blocks using the determined balance cycle interleave ratio;
• at each of a plurality of predetermined scheduling points in the balance cycle of maintenance operations, determine an updated balance cycle interleave ratio based on a current remaining amount of valid data in the fixed plurality of previously programmed blocks;
• and
• apply the updated balance cycle interleave ratio to remaining maintenance operations in the balance cycle of maintenance operations until a next scheduling point of the predetermined plurality of scheduling points.