File structure for a non-volatile block-erasable semiconductor flash memory
First Claim
1. A processor-controlled method of file management for a nonvolatile semiconductor memory with a plurality of physical erase blocks, wherein bits of the memory cannot be overwritten from a first logical state to a second logical state without a prior erasure, wherein erasure is by physical erase block and not on an individual byte basis, the method comprising the steps of:
- (1) allocating a first portion of the memory in a first physical erase block for storing an active file and a deleted file;
(2) allocating a second portion of the memory in a second physical erase block for storing a copy of the active file;
(3) storing in an allocated third portion of the memory information as to whether a portion of the memory has been allocated to store the active and deleted files or allocated to store the copy of the active file;
(4) reclaiming memory space by storing in the second portion of the memory the copy of the active file and by erasing the first physical erase block including the first portion of the memory in order to permit reuse of the first portion of the memory for storage;
(5) storing data in the first and second portions of the memory in a inked-list variable file structure.
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Accused Products
Abstract
A non-volatile semiconductor memory that is erasable only in blocks is described. Each bit of the non-volatile semiconductor memory cannot be overwritten from a first logical state to a second logical state without a prior erasure. Each bit of the non-volatile semiconductor memory can be overwritten from a second logical state to a first logical state without a prior erasure. The non-volatile semiconductor memory comprises an active block for storing a first file, a reserve block for storing a second file, and a directory block. The second file is a copy of the first file. The copy is made during a clean-up operation prior to erasure of the active block. The directory block comprises a directory entry for identifying the first file.
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Citations
16 Claims
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1. A processor-controlled method of file management for a nonvolatile semiconductor memory with a plurality of physical erase blocks, wherein bits of the memory cannot be overwritten from a first logical state to a second logical state without a prior erasure, wherein erasure is by physical erase block and not on an individual byte basis, the method comprising the steps of:
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(1) allocating a first portion of the memory in a first physical erase block for storing an active file and a deleted file; (2) allocating a second portion of the memory in a second physical erase block for storing a copy of the active file; (3) storing in an allocated third portion of the memory information as to whether a portion of the memory has been allocated to store the active and deleted files or allocated to store the copy of the active file; (4) reclaiming memory space by storing in the second portion of the memory the copy of the active file and by erasing the first physical erase block including the first portion of the memory in order to permit reuse of the first portion of the memory for storage; (5) storing data in the first and second portions of the memory in a inked-list variable file structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A processor-controlled method of file management for a nonvolatile semiconductor memory with a plurality of physical erase blocks, wherein bits of the memory cannot be overwritten from a first logical state to a second logical state without a prior erasure, wherein erasure is by physical erase block and not on an individual byte basis, the method comprising the steps of:
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(1) reclaiming memory space by copying active files and not deleted files from a first portion of a first physical erase block of the memory to a second portion of a second physical erase block of the memory and then erasing the first physical erase block including the first portion; (2) storing in a third portion of the memory information as to whether a portion of the memory is free for further data storage or in use; (3) storing data in memory free space in a sectored file structure. - View Dependent Claims (12, 13, 14, 15)
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16. A processor-controlled method of file management for a nonvolatile semiconductor first memory with a plurality of physical erase blocks, wherein bits of the first memory cannot be overwritten from a first logical state to a second logical state without a prior erasure, wherein erasure is by physical erase block and not on an individual byte basis, the method comprising the steps of:
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(1) reclaiming memory space of the first memory by copying active files and not deleted files from a first portion of a first physical erase block of the first memory to a random access memory, then erasing the first physical erase block including the first portion, and then copying active files from the random access memory back to free space of the first physical erase block of the first memory; (2) storing in a second portion of the first memory information as to whether a portion of the first memory is free for further data storage or in use; (3) storing data in free space of the first memory in a sectored file structure.
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Specification