US3760390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cylindrical domain associative memory apparatus
Assignee: NEC Corp
•
Filing: 1972-05-09
•
Granted: 1973-09-18
•
Expires: 1992-05-09
Abstract
Abstract An associative memory utilizing magnetic domain storage for selecting a stored memory word in response to an interrogating search word. A search word is compared to the tag bits of all memory words by proximately circulating magnetic domains corresponding to the memory word tag bits and the search word. For each memory word comparison process, there is a single domain placed in a first location. The circulation of the domains corresponding to the memory word tag bits and the domains corresponding to the search word causes corresponding bits, represented by the presence or absence of domains, of said tag bits and search word to simultaneously appear adjacent to said first location. If the adjacent bits are identical no resultant repelling force is applied to the domain in said first location. However, if the adjacent bits are not identical, i.e., one adjacent location contains a domain whereas the other adjacent location does not contain a domain, a resultant repellant force causes the domain in said first location to move away from said first location. After the circulation is complete, the existence of a domain in said first location, indicates that the search word is the same as the tag bits in the storage area near the first location.
Inventors
- 👤 H Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:02
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0875; G11C15/00; G11C15/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
242 words
An associative memory of the type which responds to a search word to select a stored memory word having a tag group of bits identical to said search word, said memory comprising (a) magnetic structure made of a material capable of holding cylindrical magnetic domains therein when a bias magnetic field is applied thereto, (b) means for applying a bias magnetic field thereto, (c) N groups of domain holding means on said material, each of said groups comprising a memory tag word storage portion and an identifying bit storage portion, each said identifying bit storage portion comprising first, second and third domain holding locations, (d) means for entering magnetic domains into said N memory tag word portions corresponding respectively to the tag group of bits of N stored memory words, (e) means for entering at least one domain in the first holding location of each said identifying bit storage portions, (f) means on said material for holding magnetic domains corresponding to a search word, means for entering domains into said latter means corresponding to a search word, and (g) means for moving said tag groups and said search word within said respective portions and holding means to cause movement of said domains in said identifying bit storage portions from said first locations to said second locations or third locations if and only if the tag group of bits in the corresponding tag word storage portion is not identical to said search word.
Claim 2
Dependent Claim
242 words
An associative memory of the type which responds to a search word to select a stored memory word having a tag group of bits identical to said search word, said memory comprising (a) magnetic structure made of a material capable of holding cylindrical magnetic domains therein when a bias magnetic field is applied thereto, (b) means for applying a bias magnetic field thereto, (c) N groups of domain holding means on said material, each of said groups comprising a memory tag word storage portion and an identifying bit storage portion, each said identifying bit storage portion comprising first, second and third domain holding locations, (d) means for entering magnetic domains into said N memory tag word portions corresponding respectively to the tag group of bits of N stored memory words, (e) means for entering at least one domain in the first holding location of each said identifying bit storage portions, (f) means on said material for holding magnetic domains corresponding to a search word, means for entering domains into said latter means corresponding to a search word, and (g) means for moving said tag groups and said search word within said respective portions and holding means to cause movement of said domains in said identifying bit storage portions from said first locations to said second locations or third locations if and only if the tag group of bits in the corresponding tag word storage portion is not identical to said search word.
Claim 3
Dependent Claim
70 words
An associative memory as claimed in claim 1 wherein said means for holding magnetic domains corresponding to a search word comprises N identical search word holding means, each positioned adjacent a respective one of said N identifying bit storage portions, and wherein said means for entering domains into said latter means comprises means for entering domains representing said search word into each of said N identical search word holding means.
Claim 4
Dependent Claim
107 words
An associative memory as claimed in claim 2 wherein each said identifying bit storage portion comprises magnetic elements arranged on at least one surface of said material, said magnetic elements being of the type which switch magnetic poles in response to a planar rotating magnetic field whereby said poles attract and hold domains, said magnetic elements being arranged to cause a domain at said first location to move to said second location or third location in response to a rotating magnetic field if and only if an unbalanced repelling force is applied to said domain along a first axis when said domain is in said first location.
Claim 5
Dependent Claim
124 words
An associative memory as claimed in claim 3 wherein each said memory tag word storage portion comprises magnetic elements arranged on at least one surface of said material, said magnetic elements being of the type which switch magnetic poles in response to a planar rotating magnetic field whereby said poles attract and hold domains, said magnetic elements being arranged to cause domains stored in said portion to move sequentially through a plurality of locations defined by said poles, a particular one of said locations being close enough to said first location of said identifying bit storage location to result in a domain in said particular location exerting a repelling force on a domain in said first location along said axis in a first direction.
Claim 6
Dependent Claim
126 words
An associative memory as claimed in claim 4 wherein each said search word holding means comprises magnetic elements arranged on at least one surface of said material, said magnetic elements being of the type which switch magnetic poles in response to a planar rotating magnetic field whereby said poles attract and hold domains, said magnetic elements arranged to cause domains stored in said search word holding means to move sequentially through a plurality of locations defined by said poleS, a particular one of said locations being close enough to the first location of said adjacent identifying bit storage location to result in a domain in said particular location exerting a repelling force on a domain in said first location along said axis in a second direction.
Claim 7
Dependent Claim
62 words
An associative memory as claimed in claim 5 further comprising means for detecting the presence of domains in the first locations of said N identifying bit storage portions and means for holding the magnetic domains comprising the identifying bits in said first locations during comparison of masked bits of said search word with corresponding bits of each of said memory tag word.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |