US5555387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for implementing virtual memory having multiple selected page sizes
Assignee: International Business Machines Corp
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Filing: 1995-06-06
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Granted: 1996-09-10
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Expires: 2015-06-06
Abstract
Abstract A method and apparatus for implementing virtual memory having multiple selected page sizes are provided. A virtual address includes a map index and a frame offset. A selector mechanism receives the virtual address frame offset and generates an offset and index. A frame map table indexes the virtual address map index and the selector generated index and generates a base address. The frame map table generated base address and the selector generated offset are combined to provide a physical address.
Inventors
- 👤 Mark W. Branstad
- 👤 Jonathan W. Byrn
- 👤 Gary S. Delp
- 👤 Philip L. Leichty
- 👤 Kevin G. Plotz
- 👤 Fadi-Christian E. Safi
- 👤 Albert A. Slane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:37
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/08; G06F12/10; G06F12/1009; G11; G11B; G11B25/00; G11B25/04; G11B25/043; G06F12/0223; G06F12/0292; G06F2212/00; G06F2212/65; G06F2212/652; G11B33/00; G11B33/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
136 words
An apparatus for implementing virtual memory having multiple selected page sizes comprising: a virtual address; the virtual address including a map index and a frame offset; selector means for receiving the virtual address frame offset and the multiple selected page sizes for generating an offset and index; said selector means including shifting means for generating a shifted page index; and an adder; said adder being operatively controlled by a segment size table entry and arranged to add a result of said shifting means to said result shifted back by one place; frame map table means for indexing the virtual address map index and the selector means generated index and generating a base address; and means for adding the frame map table means generated base address and the selector means generated offset and providing a physical address.
Claim 2
Independent Claim
136 words
An apparatus for implementing virtual memory having multiple selected page sizes comprising: a virtual address; the virtual address including a map index and a frame offset; selector means for receiving the virtual address frame offset and the multiple selected page sizes for generating an offset and index; said selector means including shifting means for generating a shifted page index; and an adder; said adder being operatively controlled by a segment size table entry and arranged to add a result of said shifting means to said result shifted back by one place; frame map table means for indexing the virtual address map index and the selector means generated index and generating a base address; and means for adding the frame map table means generated base address and the selector means generated offset and providing a physical address.
Claim 3
Dependent Claim
36 words
An apparatus for implementing virtual memory as recited in claim 1 wherein said selector means provides a sequence of page sizes, each sequential page size having a ratio of 1.5 to a previous adjacent page size.
Claim 4
Independent Claim
138 words
An apparatus for implementing virtual memory having multiple selected page sizes comprising: a virtual address; the virtual address including a map index and a frame offset; selector means for receiving the virtual address frame offset and the multiple selected page sizes for generating an offset and index; said selector means including means for generating a plurality of predetermined boundary values; and means for generating a limit; said limit generating means including means for receiving said virtual address frame offset and for subtracting each said predetermined boundary value from said virtual address frame offset; frame map table means for indexing the virtual address map index and the selector means generated index and generating a base address; and means for adding the frame map table means generated base address and the selector means generated offset and providing a physical address.
Claim 5
Independent Claim
138 words
An apparatus for implementing virtual memory having multiple selected page sizes comprising: a virtual address; the virtual address including a map index and a frame offset; selector means for receiving the virtual address frame offset and the multiple selected page sizes for generating an offset and index; said selector means including means for generating a plurality of predetermined boundary values; and means for generating a limit; said limit generating means including means for receiving said virtual address frame offset and for subtracting each said predetermined boundary value from said virtual address frame offset; frame map table means for indexing the virtual address map index and the selector means generated index and generating a base address; and means for adding the frame map table means generated base address and the selector means generated offset and providing a physical address.
References Cited (Backward Citations)
US4747044A
Cited
US4851989A
Cited
US5247632A
Cited
US5125086A
Cited
US5012408A
Cited
US5247638A
Cited
US5237673A
Cited
US5446854A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-10 | 2000-03-11 | 2000-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-10 | 2004-03-11 | 2004-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-10 | 2008-03-11 | 2008-09-10 | $7700.00 | Window Closed / Lapsed |