EP0031496A2
Expired / Lapsed
EP
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Cell state detection for binary signal storage device
Assignee: International Business Machines Corp
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Filing: 1980-12-04
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Granted: —
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Expires: 2000-12-04
Abstract
Abstract For signal storage systems that interrogate a storage cell with a concomitant precharging of the cell signal line (10) non-linear capacitors (40) are employed to provide automatic selective coupling of the respective signal line to a detector (200) for determination of the cell state. By connecting a plurality of signal lines to a detector through respective non-linear capacitors that assume a significantly enlarged capacitance when the precharge voltage level is asserted, enhanced coupling of the signal line may be achieved and by selectively precharging the signal line to be interrogated, no triggering of enlarged capacitance at other signal lines occurs to load the detection system. A symmetrical configuration for use with a reference comparison type of detection, may be provided. A special reference circuit (206) using a pair of joined signal lines provides a ramp signal having intermediate voltage values relative to the state-indicative signals produced by interrogated cells for the two respective cell states. By using a symmetrical configuration and a reference circuit with the same devices as the storage circuitry any shifts in characteristics as a result of manufacturing variations tend to cancel in the detection.
Inventors
- 👤 John Dennis Zbrozek
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 09:08
CPC Classifications
G; G11; G11C; G11C17/00; G11C17/08; G11C17/10; G11C17/12; G11C17/123; G11C7/00; G11C7/12; G11C7/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
263 words
Binary signal storage device responsive to an identifier signal, characterized in that it comprises : a first and a second bank of individual storage signal lines which exhibit an effective capacitance and have storage cells connected thereto that are individually selectable to control the conducting state of a discharge path for a respective signal line in accordance with a preconditioning of said cells, a comparison-type detector having first and second terminals for receiving inputs, multiplexer means responsive to said identifier signal for selectively coupling the signal line corresponding to an identified cell to an input terminal of said detector, which multiplexer means couples signal lines from said first bank to said first detector terminal and signals from said second bank to said second detector terminal, a first reference waveform circuit associated with said first bank and consisting of a pair of signal lines that are connected through a conducting link to exhibit paralleled capacitance and are connected to discharge through a network of preconditioned storage cells, a second reference waveform circuit associated with said second bank and consisting of a pair of signal lines that are connected through a conducting link to exhibit paralleled capacitance and are connected to a discharge network of preconditioned storage cells, said multiplexer means further including means for identifying the reference circuit associated with the bank that does nut include the identified cell and means for coupling the identified reference circuit to the corresponding detector input terminal, whereby a comparison of waveforms for the signal line of the identified cell and for a reference circuit may be effected.
Claim 2
Dependent Claim
263 words
Binary signal storage device responsive to an identifier signal, characterized in that it comprises : a first and a second bank of individual storage signal lines which exhibit an effective capacitance and have storage cells connected thereto that are individually selectable to control the conducting state of a discharge path for a respective signal line in accordance with a preconditioning of said cells, a comparison-type detector having first and second terminals for receiving inputs, multiplexer means responsive to said identifier signal for selectively coupling the signal line corresponding to an identified cell to an input terminal of said detector, which multiplexer means couples signal lines from said first bank to said first detector terminal and signals from said second bank to said second detector terminal, a first reference waveform circuit associated with said first bank and consisting of a pair of signal lines that are connected through a conducting link to exhibit paralleled capacitance and are connected to discharge through a network of preconditioned storage cells, a second reference waveform circuit associated with said second bank and consisting of a pair of signal lines that are connected through a conducting link to exhibit paralleled capacitance and are connected to a discharge network of preconditioned storage cells, said multiplexer means further including means for identifying the reference circuit associated with the bank that does nut include the identified cell and means for coupling the identified reference circuit to the corresponding detector input terminal, whereby a comparison of waveforms for the signal line of the identified cell and for a reference circuit may be effected.
Claim 3
Dependent Claim
130 words
Binary signal storage device according to Claim 1 characterized in that said multiplexer means includes non-linear capacitors that exhibit a relatively high capacitance for a first range of potential differences there across and a relatively low capacitance for a second range of potential differences thereacross, said capacitors connecting said individual signal lines and reference circuits to the detector terminal for the corresponding bank, and selective precharging means responsive to said identifier signal for establishing a potential difference in said first range for the identified signal line and the identified reference circuit to said detector terminals while establishing a potential difference in said second range for capacitors associated with other signal lines and the other reference circuit, whereby enhanced signal coupling is achieved for the identified signal line and reference circuit.
Claim 4
Dependent Claim
40 words
Binary signal storage device according to Claim 1 or 2 characterized in that said signal lines for each bank are parallel and the signal lines that are connected to provide a reference circuit are located centrally to their respective bank.
Claim 5
Dependent Claim
56 words
Binary signal storage device according to Claim 2 or 3 characterized in that said capacitors are depletion implanted capacitors formed on a silicon substrate, which capacitors exhibit a sharp transition from a relatively low capacitance at potential differences thereacross ranging below a threshold value and a relatively high capacitance at voltages ranging above said threshold value.
Claim 6
Dependent Claim
65 words
Binary signal storage device according to any one of claims 1 to 4 characterized in that the reference waveform circuits comprises a pair of signal lines shorted together by a connecting link to place the respective capacitances thereof in parallel and having a network of storage cells connected thereto that are conditioned to provide only a one active discharge path for said signal line pair.
Claim 7
Dependent Claim
85 words
Binary signal storage device according to Claim 5 characterized in that the storage cells associated with said pair of signal lines are connected in strings that may serve as discharge paths, the conducting state of a cell string being related to the preconditioning of the cell at a selected string position with said cells being preconditioned in a staggered pattern among the strings associated with said signal line pair to provide only one cell for completing a conducting discharge path for each selectable string position.
Claim 8
Dependent Claim
35 words
Binary signal storage device according to Claim 6 characterized in that said storage cells are field effect transistors and the preconditioning involves ion implantation to cause a respective transistor to operate in a preselected mode.
Claim 9
Dependent Claim
48 words
Binary signal storage device according to Claim 5 or 6 characterized in that a discrete tuning capacitance is connected to a signal line of said connected pair to adjust the overall capacitance of said pair to be substantially twice that of the capacitance for a single signal line.
Claim 10
Dependent Claim
156 words
Binary signal storage device according to any one of claims 2 to 8 characterised in that multiplexer means includes : first precharging means for precharging the input terminal of said detector to a first predefined voltage level, second precharging means for selectively establishing voltages on said signal lines, said second precharging means including means for decoding said cell identifier signal to identify the signal line corresponding to the identified cell, means for applying a second precharge voltage to the identified line, at a voltage level relative to said first predefined voltage, that establishes a potential difference across the respective capacitor that is in said first range, and means for applying a third precharge voltage to the signal lines other than the identified line, at a voltage level relative to said first predefined voltage that establishes a potential difference across the respective capacitors that is in said second voltage range, . whereby selective signal coupling is effected.
References Cited (Backward Citations)
No citation records indexed.
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