263results about How to "Reduce clock frequency" patented technology

A method and system for reducing the frequency of operation for a transversal Finite Impulse Response (FIR) filter is disclosed. In the preferred embodiment, the transversal filter operates in such a way that it has an even and odd row of data, which are latched on rising and falling edges of the clock respectively. This allows the clock frequency to be reduced by a factor of 2, and thus allows the use of more power efficient latches. A reduction in the frequency of operation causes the high speed latches within the transversal filter to hold the data bits twice as long as is required, which changes the desired impulse response of the FIR filter. A circuit is required to select the appropriate data bits from the output of the appropriate half-speed latch, and subsequently scale it to apply the co-efficient gain. Each of the subsystems is analog, and operates in accordance with a synchronous clock system. In a more general embodiment of the invention, the data is provided to Q shift registers that operate at a clock rate which is reduced by a factor of Q.

An equalizer provided in a digital transmitter compensates for attenuation in a signal channel to a digital receiver. The equalizer generates signal levels as a logical function of bit history to emphasize transition signal levels relative to repeated signal levels. The preferred equalizer includes an FIR transition filter using a look-up table. Parallel circuits including FIR filters and digital-to-analog converters provide a high speed equalizer with lower speed circuitry. The equalizer is particularly suited to in-cabinet and local area network transmissions where feedback circuitry facilitates adaptive training of the equalizer.

The present invention is directed to circuitry for detecting and protecting against over-clocking attacks on hardware modules. The circuitry preferably comprises a test signal, a delay path for providing a delayed signal of the test signal, and circuitry for comparing the logical state of the test signal and the delayed signal and issuing an attack indication whenever the signals are different.

Compression of signal samples output from a parallel, time-interleaved analog to digital converter (TIADC) for a baseband signal, includes calculating first or higher order differences of consecutive signal samples followed by lossless or lossy encoding of the difference samples to produce compressed samples. Compression of a TIADC output signal with a nonzero center frequency, includes calculating sums or differences of pairs of signal samples separated by an appropriate number of sampling intervals followed by lossless or lossy encoding. The sums or differences of the signal samples have lower magnitudes than the original samples, allowing more efficient compression. Lossy compression alternatives produce compressed data with a fixed bit rate or with a fixed quality in the decompressed samples. Alternatives for lossy compression include attenuating the analog signal before sampling by the TIADC, applying bit shifters or multipliers after sampling to reduce the magnitudes of the signal samples, and lossy encoding.

A method and apparatus for adjusting the clock frequency and voltage supplied to an integrated circuit is provided. A request signal is sent to the clock, and in response, the clock lowers the clock frequency supplied to the integrated circuit. A frequency detection circuit monitors the clock signal and causes a voltage regulator to reduce the voltage supplied to the integrated circuit in response to the reduced clock frequency. Similarly, a request signal is sent to the clock, and in response, the clock raises the clock frequency supplied to the integrated circuit. The frequency detection circuit monitors the clock signal and causes a voltage regulator to raise the voltage supplied to the integrated circuit in response to the increased clock frequency. The slew rate of the clock is controlled so that at least a minimum required voltage for each operating frequency is provided while the clock frequency is being changed. In this manner, reliable operation of the processor is assured while the clock speed and operating voltage are being changed.

A pipelined execution unit incorporates one or more low power modes that reduce power consumption by dynamically merging pipeline stages in an execution pipeline together with one another. In particular, the execution logic in successive pipeline stages in an execution pipeline may be dynamically merged together by setting one or more latches that are intermediate to such pipeline stages to a transparent state such that the output of the pipeline stage preceding such latches is passed to the subsequent pipeline stage during the same clock cycle so that both such pipeline stages effectively perform steps for the same instruction during each clock cycle. Then, with the selected pipeline stages merged, the power consumption of the execution pipeline can be reduced (e.g., by reducing the clock frequency and/or operating voltage of the execution pipeline), often with minimal adverse impact on performance.

A video display system, such as useful in video surveillance applications, is disclosed. The system includes a video decoder (20) having a common output data port (27) at which it presents interleaved data streams (DSA, DSB). The interleaved data streams (DSA, DSB) may correspond to multiple scalings of a processed video input signal, for example as received from a surveillance camera (C1, C2, C3, C4). The video decoder (20) also outputs multiple clock signals (CLKA, CLKB), each of which are synchronous with a corresponding one of the interleaved data streams (DSA, DSB). This enables a common data port (27) to output multiple data streams (DSA, DSB), while individual destinations (30A, 30B) of the data streams (DSA, DSB) can continue to operate at legacy clock rates.

A data processing chip with a flexible timing system and method for supplying clocks to a digital data processing system useful for power conservation. A phase locked loop generates a master clock from which a core clock and a system clock are derived. The frequency of each of the core and system clocks is independently controllable relative to the master clock and can be changed on the fly with glitch free and jitter free operation. The data processing chip is well suited for use in hand held electronic devices where power management is a concern. Power can be saved by lowering the frequency of the core clock, even for short intervals of time.

Provided is a method of reliably reducing power consumption of a computer, while promoting prompt compilation of a source code and execution of an output code. The method according to this invention includes the steps of: reading a code which is preset and analyzing an amount of operation of the CPU and an access amount with respect to the cache memory based on the code; obtaining an execution rate of the CPU and an access rate with respect to the cache memory based on the amount of operation and the access amount; determining an area in which the access rate with respect to the cache memory is higher than the execution rate of the CPU, based on the code; adding a code for enabling the power consumption reduction function to the area; and generating an execution code executable on the computer, based on the code.

A wireless receiver generates quadrature baseband signals which are sampled by a high speed analog to digital converter (IQ ADC) and also uses a receive signal strength indicator (RSSI) which is sampled by an RSSI analog to digital converter (RSSI ADC). The RSSI ADC signal is processed in combination with an end of packet signal to generate a first threshold from the average RSSI signal after the end of packet with the receive amplifiers set to a comparatively high level. A second threshold is generated by adding a threshold increment to the first threshold, and when the RSSI crosses the second threshold, the IQ ADC is taken out of a standby mode and placed in an active mode for the duration of the packet. The RSSI ADC is enabled from end of packet until packet detection by the baseband processor, and placed in standby at other times. The enabling of each respective ADC only when required reduces power consumption, and the formation of the first and second thresholds after end of packet generates a self-calibrating RSSI signal for use in enabling and disabling the IQ ADC and RSSI ADC.

Method and communications controller for processing of encoded information by a battery-powered active transponder. It is particularly provided for the application within a transponder system for the wireless payment of road toll, whereby the transponder over an antenna receives modulated microwave radiation of preset frequency for obtaining an input signal which is demodulated for obtaining a binary input data sequence. This is then fed to a digital processor (microcontroller) operated by a processing clock of preset clock frequency, for decoding and generating of a binary output data sequence, from which within a certain duration as an answer to the received input signal an output signal is formed, which is transmitted over the antenna of the transponder. For reducing the load of the battery of the transponder by the pulse-like occuring current demand of the processor with at the same time a relative short duration between the receiving of the input signal and the irradiating of the output signal, the data of the decoded input data sequence are parallel processed by the processor (17) with a relative low clock frequency. A plurality of processor modules (19-22) of the processor (17) which are integrated to a processing unit realizing the parallel occuring processing of data of the decoded input data sequence and are operated by a timing generator (symbol clock retrieving circuit 18) with a relative low clock frequency of the processing clock rate.

The invention provides an APB bridge, a control method thereof and a clock control method for an APB bus. The APB bridge comprises an AHB bus interface, an arbitration control unit and an APB bus interface, wherein the AHB bus interface is connected to an AHB bus of an advanced high-performance bus so as to communicate with AHB main equipment; the arbitration control unit is connected with the AHB bus interface and used for receiving request sent by the AHB main equipment through the AHB bus interface, judging whether the request can be executed, and sending first response to the AHB main equipment when the request can be executed so as to release the use rights of the AHB bus used by the AHB main equipment; and the APB bus interface is connected with the arbitration control unit and connected to the APB bus so as to communicate with APB slave equipment on the APB bus. The APB bridge and the control method thereof shorten the time of executing single request, and improve the performance of a system; and the clock control method controls the clock frequency of the APB bus according to the number of the requests to be executed of the APB bus, and can reduce the power consumption of the system.

Circuits and methods to achieve a low-noise and low offset continuous sigma-delta modulator used e.g. for battery management are disclosed. Continuous integration of input is enabled by special switching principle of three parallel integrators. Precharging of integrator output in so called pre-run mode minimizes integrator leakage and non-ideal effects by connecting a Gm in pre-run mode either to input voltage or to a reference voltage depending this Gm is being used in a following clock period. Parasitic effects due to switching at first integration capacitor are minimized by using buffer amplifiers tracking the voltage on integration capacitors.

A system for sensor network applications comprising a microcontroller for handling irregular events, at least one hardware accelerator for handling regular events, an event processor for interrupt handling and power management in the system, and a system bus. The microcontroller, hardware accelerator, and event processor each are connected to the system bus. The event processor gates power to the microcontroller to provide power to the microcontroller only for processing related to irregular events requiring processing by the microcontroller. The event processor further may gate power to the hardware accelerator. The system may further include a message processor and a plurality of sensors.

A clock generator and method generates a plurality of clocks of different frequencies using a delay lock loop and a sequencer. The delay lock loop receives an input clock signal having an input clock frequency and generates a plurality of delayed clock signals each having a frequency same as the input clock frequency and a different phase delay in relation to the input clock signal. The sequencer receives the delayed clock signals and selects one the delayed clock signals at any moment according to a predetermined sequence to generate an output clock signal having an output clock frequency corresponding to the predetermined sequence. The frequency of the output clock signal is controlled by the sequence in which the delayed clock signals are by the sequencer.

An image information processing system is provided, which comprises an image input section for receiving image data, a storage section for storing the image data, and a control section for controlling the image input section and the storage section. The image input section, the storage section and the control section are connected together via a data transfer bus line. An image compression section for compressing the image data is provided within or adjacent to the image input section. The control section controls the image compression section to compress non-compressed image data input from the image input section, transfers the compressed image data via the data transfer bus line to the storage section, and controls the storage section to store the compressed image data.