Abstract: Poly-phase filters are used to offer an efficient and low complexity solution to rate conversion. However, they suffer from inflexibility and are not easily reconfigured. A novel design for rate converters employ poly-phase filters but utilize interpolation between filter coefficients to add flexibility to rate conversion. This interpolation can be implemented as an interpolation of the poly-phase filter results. Additional approximations can be made to further reduce the amount of calculations required to implement a flexible rate converter.

Abstract: Laser printers are plagued with an assortment of alignment issues. In color laser printers the issues are exacerbated. Variations in distance from the mirror to the drum can lines in different color planes to vary in size. Variations in angles in the facets of the mirror can cause alignment issues between lines. Even lack of synchronization between the dot clock and start of line indication can cause misalignment between rows. In addition, a cosine distortion occurs due to the non-constant linear velocity of the laser scan of a single line. A very high speed master clock can drive the laser scanning unit. By using a very high speed clock, the control circuitry has the resolution to compensate for many of these distortion types, by appropriately counting clock cycles and indicating such to the laser modulator.

Abstract: A raster to block converter and equivalently a block to raster converter can be implemented using enough memory to contain a single image band, that is a band of pixels of height equal to a single block but spanning the entire width of an image. The raster to block converter can operate at full rate so that as soon as a pixel is read out from the memory a new pixel can be stored in its place. The location of a pixel can be tracked using a mapping involving basic modular arithmetic. This raster to block converter is scalable so that it can work with any size image and block size.

Abstract: An apparatus and methods for securely forwarding data packets at a data switching node in a data transport network is provided. The data switching node maintains a switching database of switching entries. Each switching entry has a modification protection feature preventing its modification when activated. Dynamic topology discovery of data network nodes can be disabled via topology discovery control flags associated with individual physical communications ports of the data switching node. Unknown destination flood data traffic is not replicated to physical communications ports having topology discovery disabled or specifying the suppression of replication of such unknown destination data traffic thereto. The advantages are derived from a data switching node being enabled to operate concurrently in friendly and hostile environments while detecting, preventing and reporting incidences of hostile MAC ADDR attacks.

Abstract: Direct current (DC) offset in and audio driver can cause a constant drain on power even when there is no sound. Furthermore it can cause an audible pop when the audio driver is enabled. A scaled replica output stage can be employed to perform DC offset cancellation offline during a sampling phase. Once DC offset cancellation is achieved, the audio driver uses a full scale output stage during the operation phase.

Abstract: A system for signal processing is provided. The system includes a steady state processing system for receiving a signal. A general purpose processing system is coupled to the steady state processing system and includes a signal acquisition system for receiving the signal and generating acquisition data. The steady state processing system can receive the acquisition data from the signal acquisition system and use the acquisition data to acquire the signal.

Abstract: A driver controller comprising a state machine for controlling transitions between a plurality of states. An output switch for providing a low impedance path to ground during transition periods. An output stage for decoupling output signal from driver amplifier during the transition periods.

Abstract: Multi-level cell (MLC) flash memory has become widely used due to their capacity to store more information in the same area as a single-level cell (SLC) flash memory. This makes MLC flash memory very attractive for storing media. Flash has also traditionally been used in electronic devices for firmware, but MLC flash is less reliable than SLC flash. For critical memory operations, MLC flash memory can be made as reliable as SLC flash by mapping one binary value to an MLC state corresponding to the highest threshold voltage and the other binary value to the MLC state corresponding the lowest threshold voltage when writing to the MLC flash, and by mapping all MLC states with corresponding threshold voltages above a central cutoff threshold voltage to one binary value and by mapping all MLC states with corresponding threshold voltages below a central cutoff threshold voltage to the other binary value.

Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: Laser printers are plagued with an assortment of alignment issues. In color laser printers the issues are exacerbated. Variations in distance from the mirror to the drum can lines in different color planes to vary in size. Variations in angles in the facets of the mirror can cause alignment issues between lines. Even lack of synchronization between the dot clock and start of line indication can cause misalignment between rows. In addition, a cosine distortion occurs due to the non-constant linear velocity of the laser scan of a single line. A very high speed master clock can drive the laser scanning unit. By using a very high speed clock, the control circuitry has the resolution to compensate for many of these distortion types, by appropriately counting clock cycles and indicating such to the laser modulator.

Abstract: An apparatus for detecting and controlling current. A current detector for generating a first value that represents an amount of current being delivered to a device. A current limit circuit for generating a second value that represents a maximum permitted current level from a current source. A current controller for controlling the amount of current drawn by the device if the first value exceeds the second value.

Abstract: A satellite signal demodulator is configured to use frequency-based channel scanning to sense the presence of a channel and to obtain the frequency profile of the channel. Once the channel is identified and the profile is obtained, channel extraction is used to identify the frequency parameters for a given channel. A coarse parameter estimation is performed to obtain a coarse estimate of the symbol rate (SR) and the center frequency (fc) of the channel. The coarse estimation can then be followed by a fine estimation of the symbol rate and center frequency (fc), using a bit tracking loop (BTL) lock indicator.

Abstract: A novel system (method and apparatus) for printing compressed digital images with rotation, wherein the image is rotated as an integral part of the decompression process. Furthermore, the system is configured so that selected sections of the image can be printing even as other sections of the image are still being processed. As a result, the new approach reduces system memory requirements, avoids reductions in image quality and minimizes printing delays.

Abstract: Poly-phase filters are used to offer an efficient and low complexity solution to rate conversion. However, they suffer from inflexibility and are not easily reconfigured. A novel design for rate converters employ poly-phase filters but utilize interpolation between filter coefficients to add flexibility to rate conversion. This interpolation can be implemented as an interpolation of the poly-phase filter results. Additional approximations can be made to further reduce the amount of calculations required to implement a flexible rate converter.

Abstract: An apparatus for providing real-time calibration for two or more microphones. A calibrator for receiving a left microphone signal and a right microphone signal and generating phase difference data. A phase and amplitude correction system for receiving one of the left microphone signal or the right microphone signal the phase difference data and generating calibration data for a beamformer. The beamformer receiving the calibration data, the left microphone signal and the right microphone signal and generating a monaural beamformed signal.

Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: Consumer infrared (CIR) systems typically are used in remote control systems. Most CIR systems expect a known carrier frequency and encoding scheme. However, there are many applications of a universal CIR receiver which can receive and decode CIR signals regardless of the carrier frequency or encoding scheme. A CIR receiver circuit is disclosed which can both decompose a received CIR signal into run length representation and detect the carrier frequency. The result can then be supplied to a host device for further processing, interpretation and/or actions.

Abstract: A circuit for providing a reference voltage can be widely used in audio applications. However, at startup an abrupt start in the reference signal can cause undesirable audible artifacts. A circuit employing feedback of a reference voltage to control the charging of a capacitor which provides the reference voltage can be used to provide a smooth startup to the reference voltage. The circuit contains a differential pair for steering a fixed current source from one path to another as the reference voltage increases. The steered current can then be mirrored into one or more current mirrors where the newly mirrored current can be squeezed to zero when the difference between a desired reference voltage and the reference voltage approaches zero. This newly mirrored current can be used to charge a capacitor which is used to provide the reference voltage.

Abstract: Stations in standby mode periodically wake up to check for buffered data at the access points. Traditionally, the information is available by checking the periodic beacon frame for a traffic indication map (TIM). Unfortunately, the length of beacons has steadily increased with the progression of the various wireless standards requiring stations to wake up for longer periods to merely check for buffered data. Several approaches are disclosed which address this shortcoming, including the broadcast of TIM frames, the partial reception of beacon frames and the use of an embedded TIM frame within a beacon frame.

Abstract: Broadcast and multicast (BM) systems have not been reliable in the wireless local area networks. Higher bandwidth and more reliable BM transmissions are necessitated by video and audio applications. A class of BM reliable frames is transmitted at a higher rate. The access point performs some rudimentary collision avoidance to enhance reliability, and individual stations are given the ability to send feedback to the access point regarding the quality of the transmission.