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US5859795A Expired / Lapsed US ⏱️ 0.0 years remaining

Multi-level memory circuits and corresponding reading and writing methods

Assignee: STMicroelectronics SRL
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Filing: 1997-01-30
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Granted: 1999-01-12
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Expires: 2017-01-30
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Abstract

Abstract The present invention relates to a memory circuit of the multi-level type, i.e. a memory circuit having a plurality of memory elements, each adapted to store more than one binary information unit, wherein the memory elements are utilized for storing a number of binary information units tied to an acceptable error rate for a particular application: typically, one bit where a low error rate is sought, and two bits where a higher error rate can be accepted.

Inventors

  • 👤 Paolo Rolandi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 15:31
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/56; G11C11/5621; G11C11/5642; G11C11/5628; G11C2211/00; G11C2211/56; G11C2211/564; G11C2211/5641; G11C29/00

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 148 words
A memory circuit comprising: a plurality of memory elements, each capable of storing a multiplicity of binary information units, said plurality of memory elements having at least first and second modes of operation, the memory elements being utilized in said first mode of operation as if adapted for storing each a first number of binary information units, and being utilized in said second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 2
Dependent Claim 148 words
A memory circuit comprising: a plurality of memory elements, each capable of storing a multiplicity of binary information units, said plurality of memory elements having at least first and second modes of operation, the memory elements being utilized in said first mode of operation as if adapted for storing each a first number of binary information units, and being utilized in said second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 3
Dependent Claim 19 words
A memory circuit according to claim 1, wherein said first number is one and said second number is two.
Claim 4
Dependent Claim 27 words
A memory circuit according to claim 1, wherein said plurality of memory elements are substantially identical, arranged into a matrix, and accessed through a common access circuit.
Claim 5
Dependent Claim 43 words
A memory circuit according to claim 1, wherein said control unit has control inputs and is operative to enable said modes of operation in relation to electric control signals to said control inputs concurrently with at least one of reading and writing operations.
Claim 6
Dependent Claim 44 words
A memory circuit according to claim 1, wherein said control unit has control inputs and is operative to enable said modes of operation in relation to electric control signals to said control inputs in advance of at least one of reading and writing operations.
Claim 7
Dependent Claim 31 words
A memory circuit according to claim 1, wherein said control unit is operative to define at least one of said first and second numbers in relation to said incoming selection instructions.
Claim 8
Dependent Claim 144 words
A memory circuit comprising: a plurality of memory elements divided into at least a first set and a second set, memory elements in said first set being utilized in a first mode of operation as if adapted for storing each a first number of binary information units, and memory elements in said second set being utilized in a second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 9
Dependent Claim 144 words
A memory circuit comprising: a plurality of memory elements divided into at least a first set and a second set, memory elements in said first set being utilized in a first mode of operation as if adapted for storing each a first number of binary information units, and memory elements in said second set being utilized in a second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 10
Dependent Claim 19 words
A memory circuit according to claim 7, wherein said first number is one and said second number is two.
Claim 11
Dependent Claim 27 words
A memory circuit according to claim 7, wherein said plurality of memory elements are substantially identical, arranged into a matrix, and accessed through a common access circuit.
Claim 12
Dependent Claim 30 words
A memory circuit according to claim 7, wherein said control unit is operative to define at least one of said first and second sets in relation to incoming definition instructions.
Claim 13
Dependent Claim 48 words
A memory circuit according to claim 7, wherein said control unit is operative to enable said first mode of operation when a memory element in said first set is addressed, and to enable said second mode of operation when a memory element in said second set is addressed.
Claim 14
Dependent Claim 30 words
A memory circuit according to claim 7, wherein said control unit is operative to define at least one of said first and second numbers in relation to incoming definition instructions.
Claim 15
Dependent Claim 163 words
A semiconductor integrated electronic storage device comprising: at least one memory circuit, said at least one memory circuit comprising a plurality of memory elements, each capable of storing a multiplicity of binary information units, said plurality of memory elements having at least first and second modes of operation, the memory elements being utilized in said first mode of operation as if adapted for storing each a first number of binary information units, and being utilized in said second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 16
Dependent Claim 163 words
A semiconductor integrated electronic storage device comprising: at least one memory circuit, said at least one memory circuit comprising a plurality of memory elements, each capable of storing a multiplicity of binary information units, said plurality of memory elements having at least first and second modes of operation, the memory elements being utilized in said first mode of operation as if adapted for storing each a first number of binary information units, and being utilized in said second mode of operation as if adapted for storing each a second number of binary information units, said first and second numbers being dissimilar, said numbers chosen to have at least a two-level and multi-level mode of operation, at least two input/output terminals; a multiplexer connected to said input/output terminals; and a control unit connected to said multiplexer and operative to enable said modes of operation in relation to incoming selection instructions, wherein data in one mode can be obtained from data in the other mode.
Claim 17
Dependent Claim 31 words
A device according to claim 13, further comprising a logic circuit connected to said at least one memory circuit for at least one of reading information therefrom and writing information thereto.
Claim 18
Dependent Claim 18 words
A device according to claim 13, wherein said first number is one and said second number is two.
Claim 19
Dependent Claim 26 words
A device according to claim 13, wherein said plurality of memory elements are substantially identical, arranged into a matrix, and accessed through a common access circuit.
Claim 20
Dependent Claim 42 words
A device according to claim 13, wherein said control unit has control inputs and is operative to enable said modes of operation in relation to electric control signals to said control inputs concurrently with at least one of reading and writing operations.
Claim 21
Dependent Claim 43 words
A device according to claim 13, wherein said control unit has control inputs and is operative to enable said modes of operation in relation to electric control signals to said control inputs in advance of at least one of reading and writing operations.
Claim 22
Dependent Claim 29 words
A device according to claim 13, wherein said control unit is operative to define at least one of said first and second numbers in relation to incoming definition instructions.

References Cited (Backward Citations)

JPS56153582A Cited
WO1990012400A1 Cited
EP0496288A2 Cited
US5218569A Cited
US5671388A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-01-11 2002-07-13 2003-01-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-01-11 2006-07-13 2007-01-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-01-11 2010-07-13 2011-01-12 $7700.00 Window Closed / Lapsed

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