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US5737612A Expired / Lapsed US ⏱️ 0.0 years remaining

Power-on reset control circuit

Assignee: RPX Corp
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Filing: 1994-09-30
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Granted: 1998-04-07
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Expires: 2014-09-30
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Abstract

Abstract A power-on reset control circuit and associated method for deactivating a global power-on-reset signal based on whether circuitry, critical to correct functionality of an electronic system employing the power-on reset, is functioning correctly. The power-on reset control circuit comprises a control emulation circuit for transmitting a control signal through a first control line to indicate that the circuitry is operating correctly. The power-on reset control circuit further comprises a control verification circuit, coupled to the control emulation circuit through the first control line, for deactivating the global power-on reset signal upon receiving an active local power-on reset signal indicating that the power source is providing a voltage at an operating threshold level and the active control signal from the control emulation circuit.

Inventors

  • 👤 George M. Ansel
  • 👤 Jeffery Scott Hunt
  • 👤 Christopher W. Jones
  • 👤 Jeffery Mark Marshall
  • 👤 Hatem Yazbek

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 14:28
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/24

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 110 words
A power-on reset control circuit comprising: a control emulation circuit including a plurality of integrated circuits cascaded together and capable of transmitting a control signal from a last one of the plurality of integrated circuits on a control line to indicate that the plurality of integrated circuits are operating correctly; and a control verification circuit coupled to said control emulation circuit through said control line, wherein said control verification circuit is capable of deactivating a global power-on reset signal upon receiving both an inactive local power-on reset signal indicating that a power source is providing a voltage at an operating threshold level, and said control signal in an inactive state.
Claim 2
Dependent Claim 110 words
A power-on reset control circuit comprising: a control emulation circuit including a plurality of integrated circuits cascaded together and capable of transmitting a control signal from a last one of the plurality of integrated circuits on a control line to indicate that the plurality of integrated circuits are operating correctly; and a control verification circuit coupled to said control emulation circuit through said control line, wherein said control verification circuit is capable of deactivating a global power-on reset signal upon receiving both an inactive local power-on reset signal indicating that a power source is providing a voltage at an operating threshold level, and said control signal in an inactive state.
Claim 3
Dependent Claim 246 words
A computer system comprising: processor means for processing information within said computer system; memory means for storing data to control the processing performed by said processor means; a first bus means coupled between said memory means and said processing means for transferring information between at least said memory means and said processor means; peripheral means for performing a selected operation, said peripheral means being coupled to a second bus means; a controlling means for enabling information to be transferred between said first and second bus means, said controlling means including a first plurality of integrated circuits reset by an active global power-on reset signal and at least one integrated circuit functioning independently of the power-on reset signal, a power-on reset control circuit coupled to a power source providing a ramping voltage following power up, the power-on reset control circuit comprising: a control emulation circuit including a plurality of integrated circuits cascaded together and capable of transmitting a control signal from a last one of the plurality of integrated circuits through a first control line to indicate that the plurality of integrated circuits are operating correctly; and a control verification circuit coupled to said control emulation circuit through said first control line, wherein said control verification circuit is capable of deactivating the global power-on reset signal upon receiving both an inactive local power-on reset signal indicating that the power source is providing a voltage at an operating threshold level, and said control signal in an inactive state.
Claim 4
Dependent Claim 246 words
A computer system comprising: processor means for processing information within said computer system; memory means for storing data to control the processing performed by said processor means; a first bus means coupled between said memory means and said processing means for transferring information between at least said memory means and said processor means; peripheral means for performing a selected operation, said peripheral means being coupled to a second bus means; a controlling means for enabling information to be transferred between said first and second bus means, said controlling means including a first plurality of integrated circuits reset by an active global power-on reset signal and at least one integrated circuit functioning independently of the power-on reset signal, a power-on reset control circuit coupled to a power source providing a ramping voltage following power up, the power-on reset control circuit comprising: a control emulation circuit including a plurality of integrated circuits cascaded together and capable of transmitting a control signal from a last one of the plurality of integrated circuits through a first control line to indicate that the plurality of integrated circuits are operating correctly; and a control verification circuit coupled to said control emulation circuit through said first control line, wherein said control verification circuit is capable of deactivating the global power-on reset signal upon receiving both an inactive local power-on reset signal indicating that the power source is providing a voltage at an operating threshold level, and said control signal in an inactive state.
Claim 5
Dependent Claim 15 words
The computer system according to claim 2, wherein the emulation circuitry includes a sense amplifier.
Claim 6
Dependent Claim 38 words
The computer system according to claim 2, wherein said control verification circuit includes a power-on reset generation circuit capable of deactivating said local power-on reset signal upon detecting that the power source is providing said operating threshold voltage.
Claim 7
Dependent Claim 71 words
The computer system according to claim 4, wherein said control verification circuit further includes a logic element having first and second input ports, said power-on reset generation circuit being coupled to said first input port through a power-on reset line for enabling transmission of said local power-on reset signal into said first input port and said control emulation circuit being coupled to said second input port through said first control line.
Claim 8
Dependent Claim 33 words
The computer system according to claim 5, wherein said logic element includes a set-reset latch with said first input port setting said set-reset latch and said second input port resetting said set-reset latch.
Claim 9
Dependent Claim 32 words
The power-on reset control circuit of claim 1, wherein the plurality of integrated circuits are cascaded together to limit current of the power supply during activation of the global power-on reset signal.

References Cited (Backward Citations)

US5237219A Cited
US5243233A Cited
US5477176A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-04-06 2001-10-06 2002-04-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-04-06 2005-10-06 2006-04-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-04-06 2009-10-06 2010-04-07 $7700.00 Window Closed / Lapsed

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