US3633182A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Content addressable memory cell
Assignee: AT&T Inc
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Filing: 1969-08-26
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Granted: 1972-01-04
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Expires: 1989-08-26
Abstract
Abstract A content addressable memory cell constructed from nine field effect transistors is disclosed in which the content addressing function is achieved by two of the nine field effect transistors. A memory is also disclosed to illustrate how the cell may be utilized. A second content addressable memory cell similar to the first is disclosed to show how two independent users can access the same cell.
Inventors
- 👤 James T Koo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:50
CPC Classifications
G; G11; G11C; G11C15/00; G11C15/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
209 words
In combination: a plurality of data storage cells, each comprising means for exhibiting complementary signals at first and second terminals; first and second bit access terminals; first and second nonlinear impedance elements for connecting said first and second bit access terminals to said first and second terminals respectively; first and second controlled impedance devices, each having a control terminal and first and second controlled terminals; means for connecting said control terminals of said first and second controlled impedance devices to said first and second terminals respectively; means for connecting said first controlled terminals of said first and second controlled impedance devices together to provide an output terminal; and means for directly connecting each of said second controlled terminals of said first and second controlled impedance devices to different ones of said first and second bit access terminals; a match line for directly connecting the output terminals of the plurality of cells; means for applying interrogation signals concurrently to said first and second bit access terminals of the plurality of cells; and one of said first and second controlled impedance devices responsive to the interrogation signals applied to its cell not matching information stored in that cell for conducting current from the associated bit access terminal to the match line.
Claim 2
Dependent Claim
209 words
In combination: a plurality of data storage cells, each comprising means for exhibiting complementary signals at first and second terminals; first and second bit access terminals; first and second nonlinear impedance elements for connecting said first and second bit access terminals to said first and second terminals respectively; first and second controlled impedance devices, each having a control terminal and first and second controlled terminals; means for connecting said control terminals of said first and second controlled impedance devices to said first and second terminals respectively; means for connecting said first controlled terminals of said first and second controlled impedance devices together to provide an output terminal; and means for directly connecting each of said second controlled terminals of said first and second controlled impedance devices to different ones of said first and second bit access terminals; a match line for directly connecting the output terminals of the plurality of cells; means for applying interrogation signals concurrently to said first and second bit access terminals of the plurality of cells; and one of said first and second controlled impedance devices responsive to the interrogation signals applied to its cell not matching information stored in that cell for conducting current from the associated bit access terminal to the match line.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |