US5991206A
Expired / Lapsed
US
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Method of erasing a flash memory
Assignee: FIDELIX Co Ltd
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Filing: 1998-12-08
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Granted: 1999-11-23
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Expires: 2018-12-08
Abstract
Abstract This invention discloses a method of erasing a flash memory, in which the method comprises: (A) erasing all cells of a selected sector; (B) verifying in cells whether the cells are erased; (C) saving an address corresponding to a non-erased cell and re-erasing the cells when the non-erased cell is detected by the step (B); (D) verifying in cells, from the saved address to the final address whether the cells are erased; and (E) executing a slight-program for recovering over-erased cells so that the cells of the sector are normally erased.
Inventors
- 👤 Kye Wan Shin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:25
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/34; G11C16/3404; G11C16/3409; G11C16/10; G11C16/14; G11C16/16; G11C16/3436; G11C16/344; G11C16/3445
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
A method of erasing a flash memory, comprising the steps of: (A) erasing all cells of a selected sector; (B) verifying in cells whether said cells are erased; (C) saving an address corresponding to a non-erased cell and re-erasing said cells when the non-erased cell is detected by said step (B); (D) verifying in cells, from the saved address to the final address whether the cells are erased; and (E) executing a slight-program for recovering over-erased cells so that all cells of said sector are normally erased.
Claim 2
Independent Claim
87 words
A method of erasing a flash memory, comprising the steps of: (A) erasing all cells of a selected sector; (B) verifying in cells whether said cells are erased; (C) saving an address corresponding to a non-erased cell and re-erasing said cells when the non-erased cell is detected by said step (B); (D) verifying in cells, from the saved address to the final address whether the cells are erased; and (E) executing a slight-program for recovering over-erased cells so that all cells of said sector are normally erased.
Claim 3
Dependent Claim
30 words
The method of claim 1, wherein said slight-program comprising the steps of: (a) programming said cells in bytes or words; (b) verifying in cells whether said cells are normally erased.
Claim 4
Dependent Claim
56 words
The method of claim 1, wherein said slight-program comprising the steps of; (a) verifying in bytes or words whether said cells are normally erased; (b) programming, in bytes or words, cells corresponding to failed bytes or words; and (c) re-verifying in bytes or words whether the cells corresponding to the failed bytes or words are recovered.
Claim 5
Dependent Claim
31 words
The method of claim 1, wherein said slight-program comprising the steps of: (a) programming said cells in bytes or words; and (b) verifying in columns whether said cells are normally erased.
Claim 6
Dependent Claim
46 words
The method of claim 1, wherein said slight-program comprising the steps of: (a) verifying in columns whether said cells are normally erased; (b) programming, in columns, cells corresponding to failed columns; and (c) re-verifying in columns whether the cells corresponding to the failed columns are recovered.
Claim 7
Dependent Claim
37 words
The method of claim 1, wherein said slight-program comprising the steps of: (a) executing pumping-up operation; (b) programming said cells in cells; (c) executing pumping-down operation; and (d) varying in cells whether said cells are normally erased.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-11-22 | 2003-05-24 | 2003-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-22 | 2007-05-24 | 2007-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-22 | 2011-05-24 | 2011-11-23 | $7700.00 | Window Closed / Lapsed |