Abstract: The disclosed embodiments provide a system that facilitates driving a display in a computer system. During operation, the system receives an input video stream from a graphics source, wherein the input video stream comprises a sequence of video frames. Next, the system directs the input video stream through a set of two or more memory buffers including a front buffer and a back buffer to produce an output video stream, which is used to drive the display. While directing the input video stream through the set of memory buffers, the system writes a video frame from the input video stream into the back buffer, and concurrently drives the output video stream from a preceding video frame in the front buffer. When the writing of the video frame completes, the system switches buffers so that the back buffer becomes the front buffer, which drives the output video stream, and the front buffer becomes either a spare buffer or the back buffer, which receives a subsequent frame from the input video stream.

Abstract: Some embodiments of the present invention provide a system that implements a resonant oscillator circuit. This system includes a first inductor with a constant potential terminal coupled to an input voltage, and a time-varying potential terminal coupled to a first phase output. The system also includes a second inductor with a constant potential terminal coupled to the input voltage, and a time-varying potential terminal coupled to a second phase output. The system additionally includes a first n-type transistor with a source terminal coupled to a base voltage, a drain terminal coupled to the first phase output, and a gate terminal coupled to the second phase output. The system also includes a second n-type transistor with a source terminal coupled to the base voltage, a drain terminal coupled to the second phase output, and a gate terminal coupled to the first phase output.

Abstract: A power-supply circuit is described. In particular, the power-supply circuit includes an input node configured to receive a power-supply signal, an output node configured to output a modulated power-supply signal, and a modulation mechanism coupled between the input node and the output node. This modulation mechanism is configured to modulate the power-supply signal to produce the modulated power-supply signal. Furthermore, the modulation mechanism may be configured to modulate the power-supply signal using both a first modulation and a second modulation. This first modulation is a duty-cycle modulation which controls the power output of the piezoelectric transformer signal, and the second modulation spreads harmonic energy associated with the first modulation over a range of frequencies. By spreading the harmonic energy, the perceived acoustical noise generated by the piezoelectric transformer is reduced.

Abstract: Methods and apparatuses to perform calibration of imprecise sensors for power monitoring in a data-processing system are described. The system includes a load coupled to one or more sensors. An electronic load changes a first input signal through one or more sensors by a predetermined amount. A difference in an output signal from the one or more sensors in response to the changing is obtained. The output signal is measured and sampled. A distribution of samples of the output signal is determined. The estimated parameters of the distribution that most likely to explain actual data are determined. Next, a transfer function of the one or more sensors is determined based on the estimated parameters. The input signal through the load is accurately predicted using the transfer function of the one or more sensors to monitor the power usage by the load.

Abstract: Some embodiments of the present invention provide a system that implements a resonant oscillator circuit. This resonant oscillator circuit includes: a first inductor, a second inductor, a first capacitance, and a second capacitance, wherein the first and second inductors are configured to operate with the first and second capacitances to produce resonant oscillations which appear at a first phase output and a second phase output. The system also includes a startup circuit which is configured to start the resonant oscillator circuit in a state where: the first phase output is at a peak voltage; the second phase output is at a base voltage; and currents through the first and second inductors are substantially zero. By starting the resonant oscillator circuit in this state, the oscillations commence without a significant startup transient.

Abstract: Some embodiments of the present invention provide a system that efficiently converts between a lower input voltage and a higher output voltage. This system includes an input which receives the input voltage, and an output which provides the output voltage. The system also includes a first capacitor with a higher potential terminal and a lower potential terminal, as well as a first set of switching devices which selectively couple the higher potential and lower potential terminals of the first capacitor between the input voltage, the output voltage and a base voltage. The system additionally includes a resonant clocking circuit which generates clock signals with substantially non-overlapping clock phases, including a first phase and a second phase.

Abstract: The disclosed embodiments relate to a system that implements a switched-capacitor power converter which is configured to actively control power loss while converting an input voltage to an output voltage. This system includes one or more switched-capacitor blocks (SCBs), wherein each SCB includes a first capacitor and a set of switching devices configured to couple a constant-potential terminal and a time-varying-potential terminal of the first capacitor between the input voltage, the output voltage and a reference voltage. The system also includes a clocking circuit which produces gate drive signals for switching transistors in the one or more SCBs. The system additionally includes a controller configured to actively control the gate drive signals from the clocking circuit to substantially minimize the power loss for the switched-capacitor power converter.

Abstract: Some embodiments of the present invention provide a system that implements a resonant oscillator circuit. This system includes a first inductor with a constant potential terminal coupled to an input voltage, and a time-varying potential terminal coupled to a first phase output. The system also includes a second inductor with a constant potential terminal coupled to the input voltage, and a time-varying potential terminal coupled to a second phase output. The system additionally includes a first n-type transistor with a source terminal coupled to a base voltage, a drain terminal coupled to the first phase output, and a gate terminal coupled to the second phase output. The system also includes a second n-type transistor with a source terminal coupled to the base voltage, a drain terminal coupled to the second phase output, and a gate terminal coupled to the first phase output.

Abstract: A power source, a primary inductor, a load capacitance, and one or more tuned branch resonators and switching devices are coupled to generate pulses which represent a superposition of sinusoidal waveforms. The primary inductor is connected between the power source and the load. At the start of each cycle the load is coupled to ground and each tuned-branch resonators is reinitialized to re-energize the circuits and to stabilize the waveform when the frequencies of the sinusoidal waveforms are non-periodic.

Abstract: Some embodiments of the present invention provide a system for charging a series battery, wherein the series battery is comprised of a set of banks which are connected in series, so that the same charging current passes through each bank. During the charging process, the system measures a voltage across each bank in the set of banks. The system then compares the measured voltage with a target voltage for each bank, and adjusts the charging process based on results of the comparisons between the measured voltage and the target voltage.

Abstract: A power source, a primary inductor, a load capacitance, and one or more tuned branch resonators and switching devices are coupled to generate pulses which represent a superposition of sinusoidal waveforms. The primary inductor is connected between the power source and the load. At the start of each cycle the load is coupled to ground and each tuned-branch resonators is reinitialized to re-energize the circuits and to stabilize the waveform when the frequencies of the sinusoidal waveforms are non-periodic.

Abstract: Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed.

Abstract: Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed.

Abstract: One embodiment of the present invention provides a system that facilitates temporarily increasing the operating frequency of an electronic circuit, such as a computer system, beyond a maximum sustainable operating frequency. Upon receiving a request to operate at a higher frequency, the system determines the thermal energy level of a cooling system for the circuit. If the thermal energy level is below a threshold level for the thermal capacity of the cooling system, the system increases the operating frequency of the circuit to a frequency that is greater than the maximum sustainable operating frequency for a period of limited duration. This period of limited duration is short enough to ensure that a temperature increase, caused by increasing the operating frequency, does not raise the operating temperature of the circuit above a maximum operating temperature.

Abstract: Methods and apparatuses for variable length decoding using multiple look-up tables simultaneously. In one aspect of the invention, a method for execution by a microprocessor in response to receiving a single instruction includes: receiving a string of bits; generating a plurality of indices using a plurality of segments of bits in the string of bits; looking up simultaneously a plurality of entries from a plurality of look-up tables using the plurality of indices; and combining the plurality of entries into a first result. The above operations are performed in response to the microprocessor receiving the single instruction.

Abstract: Power-efficient, pulsed driving of capacitive loads to controllable voltage levels, with particular applicability to LCDs. Energy stored in a portion of the capacitive load is recovered during a recovery phase. Time-varying signals are used to drive the load and to recover the stored energy, thus minimizing power losses, using processes named adiabatic charging and adiabatic discharging.

Abstract: Some embodiments provide a system that provides a power source. The power source includes a set of cells and a main power bus configured to connect the set of cells in a parallel configuration. The power source also includes a bidirectional converter configured to connect to one cell from the set of cells at a time. Finally, the power source includes a set of switches configured to switch each cell in the set of cells to one of the main power bus and the bidirectional converter.

Abstract: A method of operating a media player is provided. In one embodiment the method includes receiving a plurality of initially configured video settings for viewing a video segment on the media player for a desired playback duration. The method further includes determining power required to play the video segment based on the initial video settings and playing the video segment if the required power matches or is less than total power available to the media player. In another embodiment, the method may further include, if the required power exceeds the total power available to the media player, adjusting one or more of the initial video settings, either automatically or by user inputs, to reduce the power required to play the requested video segment for the desired playback duration.

Abstract: High performance clock-powered logic runs at below supply levels and reduces the need for faster digital logic circuitry. In a preferred embodiment, a clocked buffer is used to drive the signal line. The receiving end of the line is connected to a jam latch, preferably followed by an n-latch, followed by the digital logic, and followed by a second n-latch. The first n-latch is eliminated in an alternate embodiment, preferably one that uses complementary data signals.

Abstract: A system and method for efficiently charging and discharging a capacitive load from a single voltage source. The system includes a first switch for selectively connecting the voltage source to the load and a second switch for selectively providing a short across the load as may be common in the art. A particularly novel aspect of the invention resides in the provision of plural capacitive elements and a switching mechanism for selectively connecting each of the capacitive elements to the load whereby the load is gradually charged or discharged. In the illustrative embodiment, the switching mechanism includes a set of switches for selectively connecting each of the capacitive elements to the capacitive load and a switch control mechanism for selectively activating the switches.