US4751636A
Expired / Lapsed
US
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Memory management method and apparatus for initializing and/or clearing R/W storage areas
Assignee: SASIB SpA Bologna
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Filing: 1987-02-03
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Granted: 1988-06-14
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Expires: 2007-02-03
Abstract
Abstract A method for vital memory management of data. A method is disclosed for clearing on specified conditions and for assuring the clearing is effected. Both random access and stack operation are implemented. Clearing the memory area requires reading the contents of a given location and, assuming expected data is read, going on to process the next memory location. In one embodiment the contents of the given location are used to access the next location, thereby assuring that if unexpected data is read the process will not proceed normally.
Inventors
- 👤 Henry C. Sibley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:00
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/30; G06F9/30003; G06F9/3004; G06F9/30043; G11; G11C; G11C29/00; G11C29/04; G11C29/08; G11C29/10; G11C29/12; G11C29/18; G11C29/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A method useful in assuring that a computer memory area is cleared of pre-existing data before employing said memory area, which memory area is located between initial and final addresses, and is addressed by a pointer, comprising the sequential steps of: (a) initially loading said pointer with an address to a memory location between said initial and final addresses, thereby defining an addressed memory location, (b) writing a pre-determined data word into said addressed memory location so that the addressed memory location contains said pre-determined data word, (c) modifying the contents of said addressed memory location in a pre-determined fashion so that the modified contents of said addressed memory location can be used to address a different memory location in said memory area, (d) rewriting the pointer with the modified contents of the addressed memory location to address a further memory location, (e) and repeating said steps (b)-(d) for other memory locations within said memory area.
Claim 2
Independent Claim
156 words
A method useful in assuring that a computer memory area is cleared of pre-existing data before employing said memory area, which memory area is located between initial and final addresses, and is addressed by a pointer, comprising the sequential steps of: (a) initially loading said pointer with an address to a memory location between said initial and final addresses, thereby defining an addressed memory location, (b) writing a pre-determined data word into said addressed memory location so that the addressed memory location contains said pre-determined data word, (c) modifying the contents of said addressed memory location in a pre-determined fashion so that the modified contents of said addressed memory location can be used to address a different memory location in said memory area, (d) rewriting the pointer with the modified contents of the addressed memory location to address a further memory location, (e) and repeating said steps (b)-(d) for other memory locations within said memory area.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein said predetermined data word, of step (b) is a function of the address of said location, but not the address of said location.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein said predetermined fashion of step (c) comprises incrementing said contents, and said step (a) comprises loading said pointer with said initial address.
Claim 5
Dependent Claim
28 words
The method of claim 2 wherein said predetermined fashion of step (c) comprises decrementing said contents, and said step (a) comprises loading said pointer with said final address.
Claim 6
Dependent Claim
28 words
The method of claim 2 in which said pre-existing data is extracted comprising an additional step, after step (a) but before stop (b) of reading said addressed location.
Claim 7
Dependent Claim
41 words
The method of claim 1 which includes a further step, subsequent to step (e) of testing the contents of said memory area to ensure that said memory area contains predetermined contents, loaded therein, in repeated iterations of steps (b) and (c).
Claim 8
Dependent Claim
46 words
The method of claim 2 wherein said predetermined data word is a number, n, less than the address of said addressed memory location, and said predetermined fashion of step (c) comprises the step of adding the quantity n+1, to the contents of said addressed memory location.
Claim 9
Dependent Claim
46 words
The method of claim 2 wherein said predetermined data word of step (b) is a number, n, more than the address of said addressed memory location, and said predetermined fashion of step (c) comprises subtracting the quantity n-1 from the contents of said addressed memory location.
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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) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |