Non-volatile memory system allowing reverse eviction of data updates to non-volatile binary cache

摘要

A non-volatile memory system includes a memory section having a non-volatile cache portion storing data in a binary format, a primary user data storage section that stores user data in multi-state format, and an update memory area where the memory system stores data updating user data previously stored in the primary user data. The memory system allows a maximum number of blocks for use in the update memory area. When the memory system receives updated data corresponding to user data already written into the primary user data storage section, it determines whether a block of memory is available in the update memory area. In response to determining that a block of memory is not available in the update memory area, the system determines a block of the update memory to remove from the update memory; copies the data content of the determined update block into the cache portion of the memory section; and subsequently writes the updated data into the update memory.

主权项

1. A method comprising:
receiving, at a controller of a non-volatile memory system updated data corresponding to user data already written into a primary user data storage section of the non-volatile memory system, the non-volatile memory system including a controller circuit and a memory section formed on one or more integrated circuits, the memory section including a non-volatile cache portion storing data in a binary format, the primary user data storage section including flash memory wherein the non-volatile memory system stores user data in a multi-state format, and an update memory area where the non-volatile memory system stores data updating user data previously stored in the primary user data storage section, wherein the non-volatile memory system allows a maximum number of blocks of memory cells for use in the update memory area; determining whether a block of memory is available in the update memory area; in response to determining that the block of memory is available in the update memory area, writing the updated data to the available block of memory; and in response to determining that the block of memory is not available in the update memory area:
determining a block of the update memory area to remove from the update memory area;copying the data content of the determined block of the update memory area into the cache portion of the memory section; andsubsequently writing the updated data into the update memory area.