Flash memory management system and method utilizing multiple block list windows
First Claim
1. An apparatus comprising:
- a) a processor;
b) a memory coupled to the processor;
c) a flash memory management system residing in the memory and being executed by the processor, the flash memory management system including;
a free block mechanism for locating free blocks of flash memory for writing, the free block mechanism including a free block list of flash memory blocks, and further including a free block list window defining a subset plurality of the flash memory blocks in the free block list, the free block mechanism searching the subset plurality of flash memory blocks in the free block list for a flash memory block having a lowest erase count of flash memory blocks in the subset plurality of flash memory blocks in the free block list;
a disk maintenance mechanism for locating blocks of flash memory for cleaning, the disk maintenance mechanism including a block list of flash memory blocks, and further including a block list window defining a subset plurality of flash memory blocks in the block list, the disk maintenance mechanism evaluating the subset plurality of flash memory blocks in the block list to determine if any flash memory blocks in the subset plurality of flash memory blocks in the block list are candidates for cleaning.
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Accused Products
Abstract
The present invention provides a flash memory management system and method with increased performance. The flash memory management system provides the ability to efficiently manage and allocate flash memory use in a way that improves reliability and longevity, while maintaining good performance levels. The flash memory management system includes a free block mechanism, a disk maintenance mechanism, and a bad block detection mechanism. The free block mechanism provides efficient sorting of free blocks to facilitate selecting low use blocks for writing. The disk maintenance mechanism provides for the ability to efficiently clean flash memory blocks during processor idle times. The bad block detection mechanism provides the ability to better detect when a block of flash memory is likely to go bad. The flash status mechanism stores information in fast access memory that describes the content and status of the data in the flash disk. The new bank detection mechanism provides the ability to automatically detect when new banks of flash memory are added to the system. Together, these mechanisms provide a flash memory management system that can improve the operational efficiency of systems that utilize flash memory.
241 Citations
26 Claims
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1. An apparatus comprising:
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a) a processor;
b) a memory coupled to the processor;
c) a flash memory management system residing in the memory and being executed by the processor, the flash memory management system including;
a free block mechanism for locating free blocks of flash memory for writing, the free block mechanism including a free block list of flash memory blocks, and further including a free block list window defining a subset plurality of the flash memory blocks in the free block list, the free block mechanism searching the subset plurality of flash memory blocks in the free block list for a flash memory block having a lowest erase count of flash memory blocks in the subset plurality of flash memory blocks in the free block list;
a disk maintenance mechanism for locating blocks of flash memory for cleaning, the disk maintenance mechanism including a block list of flash memory blocks, and further including a block list window defining a subset plurality of flash memory blocks in the block list, the disk maintenance mechanism evaluating the subset plurality of flash memory blocks in the block list to determine if any flash memory blocks in the subset plurality of flash memory blocks in the block list are candidates for cleaning. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for managing a flash memory system comprising a plurality of flash memory blocks, the method comprising the steps of:
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a) locating free blocks of the flash memory for writing by defining a free block list of flash memory blocks and defining a free block list window defining a subset plurality of the flash memory blocks in the free black list, and by searching the subset plurality of the flash memory blocks in the free block list for a flash memory block having a lowest erase count of flash memory blocks in the subset plurality of flash memory blocks in the free block list;
b) locating blocks of the flash memory for cleaning by defining a block list of flash memory blocks and defining a block list window defining a subset plurality of the flash memory blocks in the block list, and by evaluating the subset plurality of the flash memory blocks in the block list to determine if any flash memory blocks in the subset plurality of flash memory blocks in the block list are candidates for cleaning. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A program product comprising:
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a) a flash memory management program, the flash memory management program including;
a free block mechanism for locating free blocks of flash memory for writing, the free block mechanism including a free block list of flash memory blocks, and further including a free block list window defining a subset plurality of the flash memory blocks in the free block list, the free block mechanism searching the subset plurality of flash memory blocks in a free block list for a flash memory block having a lowest erase count of flash memory blocks in the subset plurality of flash memory blocks in the free block list;
a disk maintenance mechanism for locating blocks of flash memory for cleaning, the disk maintenance mechanism including a block list of flash memory blocks, and further including a block list window defining a subset plurality of the flash memory blocks in the block list, the disk maintenance mechanism evaluating the subset plurality of flash memory blocks in a block list to determine if any flash memory blocks in the subset plurality of flash memory blocks in the block list are candidates for cleaning;
b) a computer-readable signal bearing media bearing said program. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification