International Business Machines Corporation

Sony Computer Entertainment Inc.

Other

Intel Corporation

Kabushiki Kaisha Toshiba

Toshiba America Electronic Components, Inc.

Stephen Douglas Weitzel

Joseph M Mosley

Mack Wayne Riley

Michael Fan Wang

Gilles Gervais

Jack A Dorler

David William Boerstler

Daniel Lawrence Stasiak

Nathan Paul Chelstrom

Sang Hoo Dhong

Kirk David Peterson

Richard Gerard Hofmann

Jieming Qi

Eskinder Hailu

Moises Cases

Ronald Nick Kalla

Patrick M Bland

Yosuke Muraki

James Nolan Hardage

Makoto Aikawa

Michael O Jenkins

Robert Walter Berry, Jr

Byron Lee Krauter

Dennis L Moeller

Toshihiko Himeno

Kazuhiko Miki

Iwao Takiguchi

Joachim Gerhard Clabes

Robert T Jackson

Tetsuji Tamura

Lance M Venarchick

Chiaki Takano

James D Wagoner

Suksoon Yong

Gerald A Maley

Chulwoo Kim

Erich Berndlmaier

Richard O Seeger

David George Caffo

Renitia J Bertoluzzi

Silvio Bou-Ghazale

A technology for supplying a power supply voltage to a microprocessor. Before normal arithmetic processing of the microprocessor, duty cycle correction process for adjusting the duty cycle of a clock signal inside the microprocessor is performed. In the duty cycle correction process for adjusting the duty cycle, the duty cycle of the clock signal is adjusted so as to minimize the power voltage at which the microprocessor is still operable.

Method for controlling operation of microprocessor which performs duty cycle correction process

The present invention provides for reducing current spikes in a circuit when changing clocking frequencies. A first frequency is applied to a clock distribution network. A final frequency is selected. The first frequency is applied to a logic element over the clock distribution network. A hold signal is applied to the logic element. The clock rate of the clock distribution network is changed from the first frequency to the final frequency. The hold signal is unapplied to the logic element.

Dynamic frequency scaling sequence for multi-gigahertz microprocessors

The present invention discloses, in one aspect, a synchronizing circuit for synchronizing transmitted data. In one embodiment, the synchronization technique comprises a subsystem configured to compare positive and negative transitions of a core clock signal with positive and negative transitions of a source clock signal to determine a relationship between the transitions of the core clock signal and positions of the negative transitions of the source clock signal. The synchronization circuit also comprises logic circuitry coupled to the subsystem and configured to generate a final sampling signal based on the relationship. In addition, the synchronization circuit comprises a data sampler coupled to the logic circuitry and configured to sample a source data signal synchronized with the source clock signal using the final sampling signal, and to generate a core data signal synchronized with the core clock signal based on the sampling. Also disclosed is a method of synchronizing a data stream, and a data transfer assembly incorporating the synchronization circuit and the method.

Circuit and related method for synchronizing data signals to a core clock

An apparatus, a method, and a computer program are provided to gate a Phased Locked Loop (PLL). In microprocessors, the clock distribution system can account for a substantial amount of power consumption. Gating the PLLs, however, has been difficult because of the usual requirement for a separate clock for control logic and because the PLL requires timed to reacquire phase/frequency lock. Therefore, lock detection logic can be employed to allow the PLL to reacquire phase/frequency lock. Additionally, signals from external devices and the processor can be employed to gate the PLL and allow the processor to be awakened without a need for a separate clock.

Method to gate off PLLS in a deep power saving state without separate clock distribution for power management logic

An apparatus is disclosed which includes a signal generator providing a first signal having a first frequency; a clock tree operative to propagate the first signal to at least one clock mesh of the apparatus; and a final buffer operative to receive the first signal, provide a second signal having a second frequency, synchronize the second signal with the first signal, and propagate the synchronized second signal to at least one other clock mesh of the apparatus.

Methods and apparatus for managing clock skew

An apparatus, a method, and a computer program are provided to disable clock distribution. In microprocessors, the clock distribution system can account for a substantial amount of power consumption. Disabling the clock distribution system, however, has been difficult because of the usual requirement for a separate clock for control logic. Therefore, combinational logic can be employed to disrupt the clock distribution and allow a processor to be awakened without a need for a separate clock.

Deep power saving by disabling clock distribution without separate clock distribution for power management logic

Systems and methods for circuits with substantially equal propagation delay while providing different drive strengths are disclosed. These systems and methods may allow for a circuit with a drive strength that is some ratio of an arbitrary strength full drive strength circuit. Additionally, these circuits may have substantially the same input capacitance and feedback current as the baseline drive circuit. The input of such a circuit may be coupled to three nodes, one of which is an inverter coupled to the logic to be driven, the second of which is dummy logic, and the third of which is an inverter the output of which is left floating.

Method and system for a circuit for timing sensitive applications

A lock detector and method is provided for detecting lock between first and second signals. The lock detector includes a pulse generator for receiving the first signal and generating a pulse train from the first signal. Each pulse corresponds to at least one of rising and falling edges of the first signal in each period of the first signal. The lock detector also includes a mask generator for generating a mask signal from the second signal such that the mask signal has a mask state around at least one of rising and falling edges of the second signal in each period of the second signal. Additionally, the lock detector has a logic gate, which receives the pulse train and the mask signal from the pulse generator and the mask generator, respectively. The logic gate generates an incrementing pulse signal by combining the pulse train with the mask signal.

Phase and frequency lock detector

An on-chip thermal sensing circuit is disclosed. The thermal sensing circuit including a detection circuit located on an integrated circuit (IC) for detecting a local temperature of the IC. The output of the thermal sensor has a frequency that is directly related to the local temperature. The detection circuit has an associated time constant that is used to produce the frequency.

On-chip thermal sensing circuit

A method and system for controlling a clock signal is provided. The clock signal is first stored in a storage device. An input representing a clock control signal is input into a first end of a plurality of interconnected memory storage circuits. An outputted clock signal is output from a second end of the plurality of interconnected memory storage circuits based on receipt of the pulse representing the clock control signal. In one embodiment, the plurality of interconnected memory storage circuits is comprised of latches. In an alternate embodiment, the plurality of interconnected memory storage circuits is comprised of latches and master/slave flip-flops.

Method and system for synchronously transferring data between clock domains sourced by the same clock

A bus interface apparatus and method are implemented. A pair of data streams is generated from the stream of data to be launched onto a data bus. Each stream is staged along a corresponding data path that includes a plurality of storage elements. Each path feeds an input of a multiplexer (MUX). The output of the MUX drives the bus, and the MUX selects a data value for launching onto the bus in response to a signal derived from an internal bus clock. The internal bus clock is also used to generate a bus clock that is output to the bus along with the data. The period of the bus clock may be a preselected multiple of the period of a processor clock. The data is staged along the two data streams in response to clocking signals derived from the processor clock. Each of the clocking signals is qualified by a corresponding hold signal, that, when asserted, holds the clocking signals in a predetermined state. The hold signals are generated in response to a plurality of control signals that are used to select the ratio of bus clock period to processor clock period. The bus interface may be asynchronously started in response to a signal from the startup logic in the central processing unit (CPU).

System for launching data on a bus by using first clock for alternately selecting data from two data streams and using second clock for launching data thereafter

A memory clock generator apparatus and method are implemented. The memory clock is generated, &ldquo;open loop,&rdquo; from a processor clock. The processor clock is gated into, and propagated through a shift register. A set of outputs tapped off of the shift register is decoded, along with a plurality of control signals, in AND-OR logic to generate a clock output, which may run at a predetermined multiple of the memory clock rate. The clock output may have one of a plurality of ratios of memory clock period to processor clock period. The control signals select the ratio. The clock generator may be started asynchronously, and, additionally, the generator outputs a signal to the processor having an edge that has a predetermined temporal relationship with the start of the clock generator.

Memory clock generator and method therefor

A hybrid circuit board capable of operating in a functional mode and a test mode includes macro block circuitry and non-macro block circuitry surrounding the macro block circuitry. The circuit board includes a test bridge circuit coupling the macro block circuitry to the surrounding non-macro block circuitry during the functional mode and for bypassing the macro block circuitry during the test mode. The test bridge circuit is responsive to a mode signal for isolating outputs of the macro block and for coupling the inputs of the macro block to isolated outputs of the macro block during the test mode. A mapping circuit maps the inputs of the macro block to the inputs of the non-macro circuit.

Method and apparatus for testing a hybrid circuit having macro and

A bridge for interfacing buses in a computer system having an industry standard architecture (ISA) bus and a peripheral controller interconnect (PCI) bus is coupled between the ISA and PCI buses. Devices coupled to the buses are either PCI bus-compliant devices or are non-PCI bus-compliant devices. A power management device in the computer system is able to place the computer system into a low power suspend mode, a resume mode and an active mode. The bridge has a multi-tiered arbitration device for arbitrating among the PCI bus-compliant devices and the non-PCI bus-compliant devices for control of the computer system. The arbitration device is responsive to the power management device to controllably suspend arbitration when the power management device indicates that the suspend mode is being entered.

Bridge for a power managed computer system with multiple buses and

Growing community of inventors

Round Rock, TX, United States of America

Stephen Douglas Weitzel