National Semiconductor Corporation

Sony Corporation

Michael John Shay

Richard L Duncan

Mark Douglas Koether

Robert James Divivier

Timothy Don Davis

William V Miller

Daniel Ross Herrington

Kent Bruce Waterson

Alexander Perez

Gordon Force

Thomas M Norcross

Timothy A Short

Jianhua Helen Pang

James Andrew Colgan

David Scott Weinman

Ralph Warren Haines

John R Gunther

Brian J Marley

Stephen C Pries

Dan Craig O'Neill

A power recycle circuit is for use in a power management system. An input of the power recycle circuit is for receiving a clock signal. A detection circuit is for sensing a minimum disable pulse when a clock signal is received and when a clock signal is not received. A power recycle circuit is for generating a power recycle signal in response to the minimum disable pulse. A state machine is for holding the power recycle signal for at least two clock cycles.

Power management circuit that qualifies powergood disposal signal

An electronic system is provided that includes a plurality of power consuming electronic circuits and a power management system that interfaces a power supply to the plurality of power consuming electronic circuits. The power management system includes a power level detect circuit that includes a voltage level detector circuit that receives an analog voltage level signal indicative of a level of voltage provided from the power supply. The power level detect circuitry also includes digital encoding circuitry that encodes the analog voltage level signal as a digital powered level signal also indicative of the level of the power supply voltage. Each of the power consuming electronic circuit includes configuration circuitry to receive the digital power level signal and to configure operation of that particular power consuming electronic circuit responsive to the digital power level signal.

Power management system with programable configuration circuitry using digital power level signal to selectively configure operations of electronic circuits

A driver circuit implemented in an integrated circuit for driving an output node, typically connected to another integrated circuit. The driver circuit includes a control section which produces a digital control output indicative of the state of the process used to manufacture the integrated circuit. One or more driver sections, each connected to an output node of the integrated circuit, receive the digital control output and use the output to control the state of a transistor array connected between the associated output node and circuit common. The transistor array includes an offset transistor having a channel width to channel length ratio W,/L,and a multiplicity of adjust transistors, designated first through N, having respective channel width to channel length ratios (W,/L,),approximately equal to (W,/L,) (1&plus;&Dgr;),where &Dgr; is a fixed weighted value less than one, such as 0.1. Based upon the digital control output, select circuitry is used to control the impedance between the output node and circuit common by selecting a number of the adjust transistors, with the number ranging from none to N.

Transistor channel width and slew rate correction circuit and method

A power management system is disclosed. The system includes an oscillator interface for use in a power management system, a power recycle circuit for use in a power management system, a pad clock and self test for use in a power management system, a clock enable circuit for use in a power management system, a power level detect circuit for use in a power management system, an internal source clock generation circuit for use in a power management system, and a power-save mode change detection circuit for use in a power management system. The oscillator interface includes an interle circuit for interfacing with an external oscillator used as a source of oscillations. A clock stabilization filter masks out spurious crystal frequencies in the oscillations during start-up of the power management system following an enabling of a feedback loop. The clock stabilization filter has circuitry which provides that the oscillations will start with a rising transition after filtering. A bypassing circuit enables the clock stabilization filter when the external oscillator is a crystal oscillator and for bypassing the clock stabilization filter when the external oscillator is a can oscillator. A masking circuit masks the oscillations from the rest of the power management system. The masking circuit has circuitry which disables the clock masking after a falling edge of the oscillations and stats back up with a rising transition of the oscillations.

Clock enable/disable circuit of power management system

A power management system is disclosed. The system includes an oscillator interface for use in a power management system, a power recycle circuit for use in a power management system, a pad clock and self test for use in a power management system, a clock enable circuit for use in a power management system, a power level detect circuit for use in a power management system, an internal source clock generation circuit for use in a power management system, and a power-save mode change detection circuit for use in a power management system. The oscillator interface includes an interface circuit for interfacing with an external oscillator used as a source of oscillations. A clock stabilization filter masks out spurious crystal frequencies in the oscillations during start-up of the power management system following an enabling of a feedback loop. The clock stabilization filter has circuitry which provides that the oscillations will start with a rising transition after filtering. A bypassing circuit enables the clock stabilization filter when the external oscillator is a crystal oscillator and for bypassing the clock stabilization filter when the external oscillator is a can oscillator. A masking circuit masks the oscillations from the rest of the power management system. The masking circuit has circuitry which disables the clock masking after a falling edge of the oscillations and starts back up with a rising transition of the oscillations.

Internal source clock generation circuit for use with power management

A power management system pad clock and self-test circuit includes a clock processing circuit having a input configured to receive an oscillator clock signal having a first frequency. The clock processing circuit is configured to generate a first pad clock signal having a frequency approximately equal to one-half the first frequency and a second pad clock signal having a frequency that is equal to a programmable fraction of the first frequency. The circuit also includes a main pad clock output node. Multiplexer circuitry is coupled to the clock processing circuitry and the main pad clock output node and configured to receive a plurality of peripheral signals. The multiplexer circuitry is configured to operate in a standard mode of operation wherein one of the first pad clock signal and the second pad clock signal is routed to the main pad clock output node and a first test mode of operation wherein one of the plurality of peripheral signals is selectably routed to the main pad clock output node.

Power management system that one of plurality of peripheral signals is

A circuit for controlling clock frequency change circuitry to control a frequency of a system clock in response to a clock frequency indication, wherein operating circuitry of an electronic system operates responsive to the system clock. First flip-flop circuitry has an input portion coupled to receive the clock frequency indication. The first flip flop circuitry is configured to pass data from the input portion to an output portion responsive to a first polarity transition of the internal clock. Second flip-flop circuitry has an input portion coupled to the output portion of the first flip-flop circuitry. The second flip-flop circuitry configured to pass data from an input to an output portion responsive to a second polarity transition of the internal clock. A combinatorial comparator circuit is coupled to compare the output of the first flip-flop circuitry to the output of the second flip-flop circuitry and to generate, in response thereto, an equality indicator signal to indicate a result of the comparison. The equality indicator signal provides an indication to the clock frequency change circuitry that the clock frequency is to be changed.

Clock frequency change circuit

A display controller includes a data bus interface which transfers data to the display controller from external sources. A modulation data register coupled to the data bus interface receives a first quantity of modulation data through the data bus interface. A decoder coupled to the modulation data register receives the first quantity of modulation data and decodes graphics data according to the first quantity of modulation data in order to generate display data. A modulation data address counter counts quantities of modulation data that are transferred through the data bus interface and generates a load modulation data signal when a preprogrammed total quantity of modulation data has been transferred through the data bus interface. A method used by a display controller of accessing modulation data from an external memory is also disclosed.

Display controller capable of accessing an external memory for gray

A clock generation circuit for a display controller includes an intermediate dot clock generation circuit which receives an input clock signal and in response thereto generates an intermediate dot clock signal having a plurality of dot clock pulses. A row pulse generation circuit is coupled to the intermediate dot clock generation circuit and counts the intermediate dot clock signal dot clock pulses and generates a row pulse after a predetermined number of dot clock pulses and a programmable offset time. The row pulse generation circuit also generates a final dot clock signal by masking the intermediate dot clock signal with the programmable offset time after the predetermined number of dot clock pulses. A method of adjusting a rate at which data is transferred to a display screen is also disclosed.

Clock generation circuit for a display controller having a fine tuneable

Configurable power management system having a clock stabilization filter

An input/output buffer including a bidirectional node, an output stage, an input stage, and a control circuit. The output stage has a first n-channel transistor coupled between the bidirectional node and a voltage supply node for pulling-up the bidirectional node, and first and second p-channel transistors coupled between the bidirectional node and the voltage supply node for pulling-up the bidirectional node. The input stage has a first inverter stage coupled between the bidirectional node and a first intermediate node and a second inverter stage coupled between the bidirectional node and a second intermediate node. The input stage also has a second n-channel transistor coupled between the first intermediate node and a ground node and a third n-channel transistor coupled between the second intermediate node and the ground node. The control circuit is coupled to the output stage and to the input stage and enables the output stage when in an output mode and disables the output stage when in an input mode. The control circuit has a first mode which disables the first and second p-channel transistors and enables the first n-channel transistor for operation with a first voltage supply level present at the voltage supply node and which the enables the second inverter stage and which turns the third n-channel transistor off.

Supply and interface configurable input/output buffer

An integrated circuit (IC) includes multiple circuits and functions which share multiple internal signal buses, three physical and five logical, according to distributed bus access and control arbitration. The multiple internal signal buses are shared among three tiers of internal circuit functions: a central processing unit and a DMA controller; a DRAM controller and a bus interface unit; and peripheral interface circuits, such as PCMCIA and display controllers. Two of the physical buses correspond to two of the logical buses and are used for communications within the IC. The third physical bus corresponds to three of the logical buses and is used for communications between the IC and circuits external to the IC. Arbitration for accessing and controlling the various signal buses is distributed both within and among the three tiers of internal circuit functions. Maximum performance is thereby achieved from the circuit functions accessed most frequently, while still achieving high performance from those circuit functions accessed less frequently. The IC may provided with a processor core with features that support In-Circuit Emulation (ICE).

Integrated circuit with multiple functions sharing multiple internal

The present invention is embodied in a Secured Processing Unit (SPU) chip, a microprocessor designed especially for secure data processing. By integrating keys, encryption/decryption engines and algorithms in the SPU, the entire security process is rendered portable and easily distributed across physical boundaries. The invention is based on the orchestration of three interrelated systems: (i) detectors, which alert the SPU to the existence, and help characterize the nature, of a security attack; (ii) filters, which correlate the data from the various detectors, weighing the severity of the attack against the risk to the SPU's integrity, both to its secret data and to the design itself; and (iii) responses, which are countermeasures, calculated by the filters to be most appropriate under the circumstances, to deal with the attack or attacks present. The present invention, with wide capability in all three of the detectors, filters and responses, allows a great degree of flexibility for programming an appropriate level of security/policy into an SPU-based application.

Programmable distributed personal security

A voltage level triggered ESD protection circuit is immune to standard signal transitions up to approximately 5.5 volts, does not consume any DC current either in the powered up or powered down states, and is interfaceable to a live bus when the system it is connected to is powered down. The trigger circuit is reliably immune to tripping from applied fast bus transitions on a powered-down integrated circuit. The trigger signal is generated in response to sensing both a voltage transition and to reaching a voltage set point such as 7 volts, rather than merely triggering off the voltage transition.

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Arlington, TX, United States of America

Michael John Shay