US5544119A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for assuring that an erase process for a memory array has been properly completed
Assignee: Intel Corp
•
Filing: 1995-09-06
•
Granted: 1996-08-06
•
Expires: 2015-09-06
Abstract
Abstract A method for insuring that an erase operation practiced on a block of flash EEPROM transistors is carried out reliably including the steps of: writing whenever the erasure of a block of the flash EEPROM array is to commence to a position in the array to indicate that an erasure of the block has commenced, writing whenever the erasure of a block of the flash EEPROM array is complete to the position in the array to indicate that an erasure of the block has been completed, testing to determine any positions in the array which indicate that an erasure of a block has commenced but not been completed upon applying power to the flash EEPROM array, and reinitiating an erase if any positions in the array exist which indicate that an erasure of a block has commenced but not been completed.
Inventors
- 👤 Steven E. Wells
- 👤 Eric J. Magnusson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:30
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/10; G11C16/102; G11C16/14; G11C16/16; G06F3/0628; G06F3/0662; G06F3/0664
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
A method for ensuring an erase operation has been reliably performed on a first block of a flash EEPROM memory array, the flash EEPROM memory array including a plurality of blocks, the method comprising the steps of: a) writing a first data element to a second block when the erase operation on the first block is about to commence; b) writing a second data element to the second block if the erase operation on the first block is successfully completed; c) testing the second block to determine whether the first and second data elements have been written to the second block, if power is reapplied to the flash EEPROM memory array; and d) subsequently reinitiating the erase operation on the first block if the first data element has been written to the second block and the second data element has not been written to the second block.
Claim 2
Independent Claim
147 words
A method for ensuring an erase operation has been reliably performed on a first block of a flash EEPROM memory array, the flash EEPROM memory array including a plurality of blocks, the method comprising the steps of: a) writing a first data element to a second block when the erase operation on the first block is about to commence; b) writing a second data element to the second block if the erase operation on the first block is successfully completed; c) testing the second block to determine whether the first and second data elements have been written to the second block, if power is reapplied to the flash EEPROM memory array; and d) subsequently reinitiating the erase operation on the first block if the first data element has been written to the second block and the second data element has not been written to the second block.
Claim 3
Dependent Claim
41 words
The method of claim 1, wherein the first data element is written to a data area of a sector in the second block and the second data element is written to a header area of the sector in the second block.
Claim 4
Dependent Claim
23 words
The method of claim 2, wherein the writing of the second data element in step (b) invalidates the sector in the second block.
Claim 5
Dependent Claim
23 words
The method of claim 1, wherein subsequent to the reinitiated erase operation of the first block in step (d), steps (b)-(d) are repeated.
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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) | 1999-08-06 | 2000-02-05 | 2000-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-06 | 2004-02-05 | 2004-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-06 | 2008-02-05 | 2008-08-06 | $7700.00 | Window Closed / Lapsed |