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US4458338A Expired / Lapsed US ⏱️ 0.0 years remaining

Circuit for checking memory cells of programmable MOS-integrated semiconductor memories

Assignee: Siemens AG
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Filing: 1981-08-06
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Granted: 1984-07-03
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Expires: 2001-08-06
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Abstract

Abstract Circuit arrangement for checking memory cells of programmable MOS-integrated semiconductor memories, especially non-volatile semiconductor memories of the floating-gate type, has an active programming and read mode of operation wherein all word lines of the semiconductor memory with the exception of one selected word line are at a low level. The circuit arrangement also has an inactive power-down mode of operation, wherein all word lines at a high level. Both of the modes of operation are represented by a signal having a first level for the active mode of operation and a second level for the inactive mode of operation. The circuit arrangement further includes a single circuit in the semiconductor memory switchable via a first signal indicating the operating mode for the memory cell test, wherein all of the word lines are addressed by a voltage corresponding to the programming voltage, as a function of a single second signal fed into the semiconductor memory from the outside, from the level indicating the active mode of operation to the level indicating the inactive mode of operation, so that all the word lines can be switched simultaneously to the level required for programming.

Inventors

  • 👤 Burkhard Giebel
  • 👤 Hans Moormann
  • 👤 Lothar Schrader

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 02:57
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/04; G11C29/08; G11C29/12; G11C29/46; G11C29/18; G11C29/30; G11C29/34

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 185 words
Circuit arrangement for checking memory cells of programmable MOS-integrated semiconductor memories, especially non-volatile semiconductor memories of the floating-gate type, having an active programming and read mode of operation, wherein all word lines of the semiconductor memory with the exception of one selected word line are at a low level, and having an inactive power-down mode of operation, wherein all word lines are at a high level, both of the modes of operation being represented by a signal having a first level for the active mode of operation and a second level for the inactive mode of operation, comprising a single circuit in the semiconductor memory switchable via a first signal indicating the operating mode for the memory cell test, wherein all of the word lines are addressed by a voltage corresponding to the programming voltage, as a function of a single, second signal fed into the semiconductor memory from the outside, from the level indicating the active mode of operation to the level indicating the inactive mode of operation, so that all the word lines can be switched simultaneously to the level required for programming.
Claim 2
Dependent Claim 185 words
Circuit arrangement for checking memory cells of programmable MOS-integrated semiconductor memories, especially non-volatile semiconductor memories of the floating-gate type, having an active programming and read mode of operation, wherein all word lines of the semiconductor memory with the exception of one selected word line are at a low level, and having an inactive power-down mode of operation, wherein all word lines are at a high level, both of the modes of operation being represented by a signal having a first level for the active mode of operation and a second level for the inactive mode of operation, comprising a single circuit in the semiconductor memory switchable via a first signal indicating the operating mode for the memory cell test, wherein all of the word lines are addressed by a voltage corresponding to the programming voltage, as a function of a single, second signal fed into the semiconductor memory from the outside, from the level indicating the active mode of operation to the level indicating the inactive mode of operation, so that all the word lines can be switched simultaneously to the level required for programming.
Claim 3
Dependent Claim 28 words
Circuit arrangement according to claim 1, wherein the semiconductor memory has an external address terminal for feeding in said second signal to the semiconductor memory from the outside.
Claim 4
Dependent Claim 45 words
Circuit arrangement according to claim 1 wherein said circuit has a voltage discriminator and an MOS switching transistor addressed by said voltage discriminator, a line, via which said first signal indicating the operating mode is supplied, being shortable to ground through said MOS switching transistor.
Claim 5
Dependent Claim 21 words
Circuit according to claim 3, wherein said voltage discriminator comprises an even number of series-connected inverter stages formed of MOS transistors.
Claim 6
Dependent Claim 22 words
Circuit according to claim 1, 3, wherein said voltage discriminator is made up of four series-connected inverter stages formed of MOS transistors.

References Cited (Backward Citations)

US4094012A Cited
JPS5622278A Cited
US4342103A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-07-03 1988-01-02 1988-07-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-07-03 1992-01-02 1992-07-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-07-03 1996-01-02 1996-07-03 $7700.00 Window Closed / Lapsed

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