US3704452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shift register storage unit
Assignee: International Business Machines Corp
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Filing: 1970-12-31
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Granted: 1972-11-28
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Expires: 1990-12-31
Abstract
Abstract A data storage unit is provided in which groups or ''''pages'''' of data including their addresses are stored in shift registers in successive positions, the registers being operable on a signal requesting access to shift their contents repetitively to the next position in one or more loops which include a position wherein a page may be accessed and in one or more loops which excludes said access position. Controls are provided for varying the shifting in said loops such that the positions of some or all of the pages of separately accessed classes are dynamically reordered so that they are presented to said access position on such signal in approximately or exactly the order in which they were last requested, thus reducing average access time in programs involving considerable repeated reference to a limited group of pages of the class.
Inventors
- 👤 William F Beausoleil
- 👤 David T Brown
- 👤 William A Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:38
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/76; G06F7/78; G06F3/00; G06F3/007; G11; G11C; G11C19/00; G11C19/28; G11C19/287
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
235 words
A storage unit for signals representative of pages of data and their addresses which comprises: plural shift registers for storing said signals in a like plurality of related positions, the related positions containing signals representative of the data bits and address bits constituting a page, there being an access position wherein the data bits of the page are accessible to a using unit; shift means interconnecting said positions of said shift registers for shifting said pages from position to position in at least one shift loop which includes said access position and at least one other shift loop which excludes said access position; address signalling means for providing signals representative of the address bits of a page requested by a using unit; detector means responsive to said address signalling means and said address bits in said plural shift registers for determining the presence in the access position of a requested page; means for enabling access to the data bits of a requested page while in said access position; and control means connected to said shift means and said detector means for controlling the shifting of said pages in said respective one or the other shift loops so that pages most recently shifted to said access position are maintained in positions for subsequent successive shifting into said access position on a priority basis to other pages when the requested page is not initially in that position.
Claim 2
Dependent Claim
235 words
A storage unit for signals representative of pages of data and their addresses which comprises: plural shift registers for storing said signals in a like plurality of related positions, the related positions containing signals representative of the data bits and address bits constituting a page, there being an access position wherein the data bits of the page are accessible to a using unit; shift means interconnecting said positions of said shift registers for shifting said pages from position to position in at least one shift loop which includes said access position and at least one other shift loop which excludes said access position; address signalling means for providing signals representative of the address bits of a page requested by a using unit; detector means responsive to said address signalling means and said address bits in said plural shift registers for determining the presence in the access position of a requested page; means for enabling access to the data bits of a requested page while in said access position; and control means connected to said shift means and said detector means for controlling the shifting of said pages in said respective one or the other shift loops so that pages most recently shifted to said access position are maintained in positions for subsequent successive shifting into said access position on a priority basis to other pages when the requested page is not initially in that position.
Claim 3
Dependent Claim
32 words
A storage unit according to claim 1 wherein said control means is arranged to terminate shifting in a loop including said access position when the requested page is shifted into that position.
Claim 4
Dependent Claim
16 words
A storage unit according to claim 1 wherein said detector means comprises an address comparison unit.
Claim 5
Dependent Claim
158 words
A storage unit according to claim 2 wherein said shift means includes means to control said shift registers to shift a group of said pages in opposite directions, and said control means causes the shifting of said shift registers in a first direction in a shift loop including said access position when the requested page is not initially in that position until the requested page is shifted into that position as determined by said detector means and thereupon causes the shift registers to shift in the second, opposite direction in a loop excluding said access position until the page initially in said access position is located in the position first shifted into said access position on the shift of said pages in said first direction, and thereupon to terminate shifting in said second direction, so that the pages eventually become oriented in the direction of shift into said access position in accordance with recency of requested access thereto.
Claim 6
Dependent Claim
18 words
A storage unit according to claim 4 wherein said pages includes all the pages of the storage unit.
Claim 7
Dependent Claim
16 words
A storage unit according to claim 4 wherein said shift registers are of the static type.
Claim 8
Dependent Claim
214 words
A storage unit according to claim 1 wherein: said shift means includes means interconnecting said positions of said shift registers to shift a first group of said pages in a first loop which includes said access position, to shift a different, second group of said pages in a second loop which excludes said access position, and to shift both of said groups of pages simultaneously in a third loop which includes said access position; additional detector means connected to said address signalling means and said address bits in said shift registers for detecting the presence of the requested page in a position of said second loop from which it may be shifted into said access position when said page loops are shifted in said third loop, and to provide a match signal indicative thereof; and said control means includes means responsive to said match signal to cause termination of shifting in said second loop and to cause shifting in said third loop to shift the requested page into said access position, to shift the page previously in said access position into a page position of said first group, and to shift a page of said first group into a page position of said second loop to replace said page shifted into said access position.
Claim 9
Dependent Claim
48 words
A storage unit according to claim 7 wherein said control means includes means connected to said detector means arranged to terminate shiftiNg in either of said first and third loops when the requested page is shifted into said access position from a page position of the corresponding loop.
Claim 10
Dependent Claim
28 words
A storage unit according to claim 8 wherein said control means includes means connected to said shift means to cause simultaneous shifting in said first and second loops.
Claim 11
Dependent Claim
69 words
A storage unit according to claim 7 wherein said shift means includes means interconnecting said positions of said shift registers to shift the pages of said first group other than the page in said access position in a fourth loop excluding said access position, and said control means includes means connected to said shift means to couple said fourth loop to said access position to form said first loop.
Claim 12
Dependent Claim
19 words
A storage unit according to claim 7 wherein said positions of said shift registers are interconnected to shift unidirectionally.
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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) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |