SCHEDULING PHASED GARBAGE COLLECTION AND HOUSE KEEPING OPERATIONS IN A FLASH MEMORY SYSTEM

• US 20090006720A1
• Filed: 06/27/2007
• Published: 01/01/2009
• Est. Priority Date: 06/27/2007
• Status: Abandoned Application

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Traister, Shai
• Application Number:
  US11/769,038
• Publication Number:
  US 20090006720A1
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 13/1642 with request queuing
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control

Abstract

An embodiment of a non-volatile memory storage system comprises a memory controller, and a flash memory module. The memory controller manages the storage operations of the flash memory module. The memory controller is configured to assign a priority level to one or more types of house keeping operations that may be higher than a priority level of one or more types of commands received by a host coupled to the storage system, and to service all operations required of the flash memory module according to priority.

Claims

1. A flash memory storage system comprising:

a memory controller;

flash memory module; and

a back end manager that prioritizes data storage operations of the flash memory module,

the back end manager configured to analyze a group of the data storage operations required of the flash memory module, and

configured to determine if a host command has a lower priority than an internal operation of the flash memory storage system, if so determined perform at least a portion of the internal operation before the host command.

2. The flash memory storage system of claim 1, wherein the back end manager comprises firmware of the system.

3. The flash memory storage system of claim 1, wherein the back end manager comprises a state machine.

4. A flash memory storage system comprising:

a memory controller; and

a flash memory module,

the memory controller configured to;

assign a priority level to one or more types of house keeping operations higher than a priority level of one or more types of commands received by a host coupled to the storage system;

process a host command;

compare a priority level of the host command to a priority level of a house keeping operation; and

cause at least a portion of one house keeping operation determined to have a higher priority level than the received command to be serviced by the flash memory module before causing the received command to be serviced by the flash memory module.