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US4882711A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-volatile memory system

Assignee: NXP USA Inc
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Filing: 1988-02-03
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Granted: 1989-11-21
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Expires: 2008-02-03
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Abstract

Abstract A memory system comprising a first, volatile memory (6) having a plurality of memory cells; at least one second, non-volatile memory (E l E n ) having a plurality of memory cells; power-down means (12) for sensing when power is withdrawn from the first memory and for transferring in response thereto contents of the cells of the first memory to the cells of the second memory; and power-up means (10) for sensing when power is applied to the first memory and for transferring in response thereto contents of the cells of the second memory to the cells of the first memory, is characterised by a plurality of said second, non-volatile memories and further comprising a register (8) for holding an indication of which of the second memories is to be used for transfer by at least the power-down means.

Inventors

  • 👤 Pierre Guillot

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 12:47
CPC Classifications
G; G11; G11C; G11C14/00

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 123 words
A memory system comprising: a first volatile memory having a plurality of memory cells; a plurality of second, non-volatile memories each having a plurality of memory cells; a register for holding an indication of a predetermined one of the plurality of second memories; power-down means fro sensing when power is withdrawn from the first memory and for transferring in response thereto contents of the cells of the first memory to the cells of the predetermined one of the plurality of second memories whose indication is held in the register; and power-up means for sensing when power is applied to the first memory and for transferring in response thereto contents of the cells of a second memory to the cells of a first memory.
Claim 2
Dependent Claim 123 words
A memory system comprising: a first volatile memory having a plurality of memory cells; a plurality of second, non-volatile memories each having a plurality of memory cells; a register for holding an indication of a predetermined one of the plurality of second memories; power-down means fro sensing when power is withdrawn from the first memory and for transferring in response thereto contents of the cells of the first memory to the cells of the predetermined one of the plurality of second memories whose indication is held in the register; and power-up means for sensing when power is applied to the first memory and for transferring in response thereto contents of the cells of a second memory to the cells of a first memory.
Claim 3
Dependent Claim 43 words
The memory system according to claim 1 wherein the register is a non-volatile register and the power-up means is arranged to transfer contents of the cells of the predetermined one of the plurality of second memories whose indication is held by the register.
Claim 4
Dependent Claim 20 words
A memory system accordsing to claim 1 wherein the power-up and power-down means transfer the contents of all cells simultaneously.

References Cited (Backward Citations)

US4712195A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-11-20 1993-05-22 1993-11-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-11-20 1997-05-22 1997-11-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-11-20 2001-05-22 2001-11-21 $7700.00 Window Closed / Lapsed

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