Abstract: An apparatus and method for adjusting the pixel resolution of an input image is disclosed. According to the present invention, the pixel resolution of the input image is adjusted by oversampling an analog signal representative of the input image at a higher frequency than the pixel rate of the original image, then digitally downscaling to the desired horizontal resolution of an output image. The horizontally downscaled image is then stored in a buffer memory and subsequently scaled up to the desired vertical resolution of the output image. Preferably, oversampling of the analog signal is performed at a frequency that is an integer multiple of the input pixel rate, thus providing coherent sampling to help avoid aliasing artifacts in the sampled image.

Abstract: The present invention provides a passive RFID chip with on-chip charge pumps for generating electrical power for the chip from radio frequencies. The passive RFID chip comprises an analog portion and a digital portion. The analog portion primarily comprises a voltage sensor and an AM data detector. The digital portion comprises a state machine digital logic controller. Incoming RF signals enter the chip via external antennas. The RF signals are converted into regulated DC signals by RF-DC converters with the voltage sensor. The RF-DC converters provide power for all the on-chip components and hence the chip does not require external power supply. The incoming RF signals are demodulated by demodulators and enter the AM data detector where the envelope transitions are detected. A voltage alarm is provided to ensure the voltage level does not drop below an operational level of the chip.

Abstract: The present invention provides a passive RFID chip with on-chip charge pumps for generating electrical power for the chip from radio frequencies. The passive RFID chip comprises an analog portion and a digital portion. The analog portion primarily comprises a voltage sensor and an AM data detector. The digital portion comprises a state machine digital logic controller. Incoming RF signals enter the chip via external antennas. The RF signals are converted into regulated DC signals by RF-DC converters with the voltage sensor. The RF-DC converters provide power for all the on-chip components and hence the chip does not require external power supply. The incoming RF signals are demodulated by demodulators and enter the AM data detector where the envelope transitions are detected. A voltage alarm is provided to ensure the voltage level does not drop below an operational level of the chip.

Abstract: The present invention provides a passive RFID chip with on-chip charge pumps for generating electrical power for the chip from radio frequencies. The passive RFID chip comprises an analog portion and a digital portion. The analog portion primarily comprises a voltage sensor and an AM data detector. The digital portion comprises a state machine digital logic controller. Incoming RF signals enter the chip via external antennas. The RF signals are converted into regulated DC signals by RF-DC converters with the voltage sensor. The RF-DC converters provide power for all the on-chip components and hence the chip does not require external power supply. The incoming RF signals are demodulated by demodulators and enter the AM data detector where the envelope transitions are detected. A voltage alarm is provided to ensure the voltage level does not drop below an operational level of the chip.

Abstract: A data recovery circuit for use in a data receiving system to recover an m-bit data stream from an n-bit data stream. The data recovery circuit comprises an n-bit data reconstruction circuit for selecting a data boundary in response to a boundary selection signal and producing a reconstructed n-bit data stream based on the boundary data, a FIFO buffer circuit for temporarily storing the reconstructed n-bit data stream and reading out the m-bit data stream, and a detection circuit for detecting whether the m-bit data stream from the FIFO buffer circuit conforms to a predetermined format and thereby producing a boundary selection signal for controlling the data boundary selection of the n-bit data reconstruction circuit.

Abstract: A clock generator capable of providing low-jitter clock signals without utilization of a crystal oscillator is introduced. The present invention clock generator utilizes a diode in related biasing circuit such that the generated control current to a current control oscillator is stable and clear due to the low flicker noise and low thermal noise of the voltage across the diode. The cost of PLL systems utilizing the present invention clock generator instead of a crystal oscillator is decreased. The adopted biasing circuit is introduced as well.

Abstract: A video signal processing system capable of adjusting errors and related methods are introduced. The video signal processing system and related calibration methods utilize the characteristic of periodic breaks of video signals to perform various kinds of calibrations including gain calibration of ADC, offset calibration of ADC, dc-level shifting of input signals, and quatization errors spreading by adding analog random signals to input video signals. The required high accuracy in video signal processing systems is achieved in the present invention with the claimed calibration methods.

Abstract: A frequency synthesizer that includes two fractional dividers, two noise-shaped quantizers, three integer dividers, a PLL, an algorithm embodied in control logic, and an adjustment means. The noise-shaped quantizers are used to quantize two fractional (fixed-point) values, derived from the divider control words, into time-varying values. The dividers and PLL are used to generate an output signal by means of multiplying a reference signal by the quotient of the divider control word values. Accordingly, the frequency synthesizer of the present invention can provide a very precise output clock, with the average output frequency being the input frequency multiplied by the quotient of the two divider control words, and with high jitter stability.

Abstract: The present invention provides a frequency synthesizer comprising a noise-shaped quantizer and a divider. The noise-shaped quantizer is utilized for quantizing a period control word to a time-varying value. The divider is used for generating an output signal by of dividing a reference signal by the time-varying value. The output signal is fed back to the noise-shaped quantizer so that the noise-shaped quantizer generates the time-varying value in response to the feedback output signal. Accordingly, the frequency synthesizer of the present invention can provide a very precise frequency synthesizer featuring very accurate long-term phase, frequency, and jitter stability.

Abstract: The present invention provides a passive RFID chip with on-chip charge pumps for generating electrical power for the chip from radio frequencies. The passive RFID chip comprises an analog portion and a digital portion. The analog portion primarily comprises a voltage sensor and an AM data detector. The digital portion comprises a state machine digital logic controller. Incoming RF signals enter the chip via external antennas. The RF signals are converted into regulated DC signals by RF-DC converters with the voltage sensor. The RF-DC converters provide power for all the on-chip components and hence the chip does not require external power supply. The incoming RF signals are demodulated by demodulators and enter the AM data detector where the envelope transitions are detected. A voltage alarm is provided to ensure the voltage level does not drop below an operational level of the chip.

Abstract: A data recovery circuit for use in a data receiving system to recover an m-bit data stream from an n-bit data stream. The data recovery circuit comprises an n-bit data reconstruction circuit for selecting a data boundary in response to a boundary selection signal and producing a reconstructed n-bit data stream based on the boundary data, a FIFO buffer circuit for temporarily storing the reconstructed n-bit data stream and reading out the m-bit data stream, and a detection circuit for detecting whether the m-bit data stream from the FIFO buffer circuit conforms to a predetermined format and thereby producing a boundary selection signal for controlling the data boundary selection of the n-bit data reconstruction circuit.

Abstract: A PLL architecture with fast phase acquisition, a stable freerun output frequency, and post-freerun fast phase recovery. The invention is particularly well suited for use in a video graphics a/d conversion circuit. An intelligent phase lock loop is optimized to determine the time difference between the closest rising edge of an PLL output signal and the rising edge of an input signal. The time difference in combination with the current PLL lock state determine an operational code used in a digital signal processing loop filter used to control a digitally controlled oscillator. The PLL also provides a stable output frequency during freerun periods, and a phase booster circuit for post-freerun fast phase recovery.

Abstract: A logic system with adaptive supply voltage control comprising a logic circuit clocked by a clock signal from a clock generating circuit and a voltage conversion circuit for generating a dynamically regulated supply voltage for powering the logic circuit. A critical path delay of the logic circuit is designed to be equal to or shorter than a period of the clock signal. The voltage conversion circuit dynamically regulates the supply voltage of the logic circuit based on a bias voltage of the clock generating circuit. According to the invention, the power consumption is effectively minimized while ensuring the logic circuit to function correctly throughout all conditions.

Abstract: In the data recovery circuit of the invention, a first group of sampling clock pulses is used for sampling approximately the central portions of the data bits in an incoming data stream to produce a first sampled data stream, while a second group of sampling clock pulses is used for sampling approximately the transition portions between every two adjacent data bits in the incoming data stream to produce a second sampled data stream. By detecting the resemblance of each bit in the second sampled data stream to the corresponding two adjacent bits in the first sampled data stream, a phase detection and correction circuit determines an early condition or a late condition for the phases of the sampling clocks and produces a signal to correct the phases of the sampling clocks by shifting the phases backwards or forwards. According to the invention, sampling clocks with lower frequencies can be used for sampling, and the phase error can be corrected to obtain the correct data recovery.

Abstract: The present invention provides a frequency synthesis circuit. The frequency synthesis circuit includes a noise-shaping quantizer and a digitally controlled oscillator. The noise-shaping quantizer responsive to a plurality of input bits for shaping error signals resulting from the quantization conversion such that most of the error occurs at high frequency. The digitally controlled oscillator is connected to the output of the quantizer having an output frequency responsive to the output of the quantizer.

Abstract: An interface circuitry of a display chip is disclosed. According to the present invention, the interface circuitry comprises an input node, a filter and a clamping circuit. The input node is used for receiving an analog image signal. The filter is utilized for processing the analog image signal and providing a processed image signal at an internal node. The clamping circuit is connected between the internal node and a reference level. The clamping circuit is used to clamp the processed image signal by the reference level during a clamping interval.

Abstract: An apparatus and method for masking interference noise contained in a signal source. According to the present invention, the apparatus comprises: a pseudo random binary sequence generator for generating a digital dither signal; a scrambler for receiving an offset signal and generating a dithered offset signal by scrambling the offset signal with the digital dither signal; a digital-to-analog converter for converting the dithered offset signal into an analog dithered offset signal; a summing device for generating a dithered image signal in response to the analog dithered offset signal and the analog image signal; and an analog-to-digital converter for converting the dithered image signal into the digital image signal.

Abstract: The present invention provides a phase-locked loop that comprises a divider, a noise-shaped quantizer, a filter, a phase detector and digital loop filter. The divider is used for receiving a reference clock with a substantially fixed period and generating an output clock with a time-varying period. The noise-shaped quantizer is used for quantizing a period control word to a time-varying value in response to the output clock fed from the divider so that the divider generates the output clock by means of dividing the reference clock by the time-varying value. The filter is employed to substantially filter out jitter from the output clock. The phase detector is used for generating a phase error in response to the filtered output clock and an input signal. The digital loop filter is used for generating the period control word in response to the phase error.

Abstract: The present invention provides a frequency synthesizer comprising a noise-shaped quantizer and a divider. The noise-shaped quantizer is utilized for quantizing a period control word to a time-varying value. The divider is used for generating an output signal by means of dividing a reference signal by the time-varying value. The output signal is fed back to the noise-shaped quantizer so that the noise-shaped quantizer generates the time-varying value in response to the feedback output signal. Accordingly, the frequency synthesizer of the present invention can provide a very precise frequency synthesizer featuring very accurate long-term phase, frequency, and jitter stability.

Abstract: The present invention provides a digital spread spectrum frequency synthesizer that comprises a noise-shaped quantizer, a divider and an adjustment means. The noise-shaped quantizer is used to quantize a period control word to a time-varying value. The divider is used for generating an output signal by means of dividing a reference signal by the time-varying value, the output signal feeding back to the noise-shaped quantizer so that the noise-shaped quantizer generates the time-varying value in response to the feedback output signal. The adjustment means is used to adjust the period control word by a period offset in response to the output clock. Accordingly, the frequency synthesizer of the present invention can provide a very precise frequency synthesizer featuring a precision spread spectrum clock and jitter stability as well.