Abstract: Modern fiber optic networks typically transfer data using encoding in which the clock is transmitted along with the data, for example in NRZ format. In order to use the clock to process the data, the clock signal must be extracted from the data signal. Because the data and clock may travel through different circuit paths they may have different propagation delays and a phase offset between the clock and data may result. Data and clock phase offsets are more problematical as data transmission speed increases. Furthermore the data/phase offset is typically not constant and may change with a variety of variables. To compensate for the changing offset, one or more variable delays are inserted in the phase detector circuitry. The timing of the variable delay is controlled by a bang-bang phase detector, such as an Alexander phase detector, which determines if the clock is leading, lagging, or in phase with the data.

Abstract: An improved echo canceler training technique may be employed by a digital server modem in a PCM modem context, such as a V.90 modem system. The disclosed echo canceler training technique establishes the digital impairments within the echo path by transmitting a training signal from a transmitter located at the digital server modem. The echo signal generated in response to the training signal is received by the digital server modem and appropriately analyzed to accurately model the echo path. The echo canceler resident at the server modem is than suitably trained to compensate for the modeled echo path. In the preferred embodiment, the echo canceler training signal is also used during in the context of downstream digital impairment learning by the analog client modem. In the context of the echo canceler training, the server modem does not rely upon any processing or analysis performed by the client modem; the server modem trains its echo canceler without receiving any information from the client modem.

Abstract: A multi-task structure for a software modem including a plurality of self-contained executable entities. The executable entities include at least a controller and a data pump with the controller operating as an interface between an operating system driver and the data pump when signals are passed from the operating system driver to the data pump. In addition, the data pump includes at least a scheduler and a hardware driver, the scheduler interacting with additional self-contained executable entities and enabling the data pump to operate using one or more individual ones of the additional self-contained executable entities according to the signals passed from the controller to the data pump.

Abstract: A communication system for monitoring and/or controlling communication parameters of a communication device. The communication system monitors a communication channel that is created when the communication device connects to a network, controls the communication device as it operates on the network, and configures the communication device. The communication device is commonly a modem and is communicatively coupled to the network to carry out ongoing communications between the modem and the network through the communication channel. Further, a software module is associated with the modem, and the software module accesses the internal settings of the modem via the communication channel (if necessary) and performs operations such as monitoring, controlling, and configuring the modem (or other communication device) using the internal settings of the modem.

Abstract: Method for fabrication of on-chip inductors and related structure are disclosed. According to one embodiment, inductors are formed by patterning conductors within a certain dielectric layer in a semiconductor die. Thereafter, the entire dielectric layer in the semiconductor die is subjected to a blanket implantation or sputtering of high permeability material. According to another embodiment, a first area in a semiconductor die is covered, for example, with photoresist. A second area in the semiconductor die includes a patterned conductor which is to be used as an inductor. The patterned conductor is also covered, for example, with photoresist. The second area, excluding the covered patterned conductor is subjected to implantation or sputtering of high permeability material. According to yet another embodiment, a first area of a semiconductor die is covered, for example, with photoresist. A second area in the semiconductor area includes a patterned conductor which is to be used as an inductor.

Abstract: Various exemplary aspects of the present invention provide methods and apparatus for powering down the line driver to a state that reduces power dissipation without affecting the overall impedance of the line driver. More particularly, a power down state for line drivers and the like is suitably provided that saves power when no transmission is required. The power down mode suitably provides line termination for received data. According to various aspects of an exemplary embodiment, output devices are configured at power down such that a low impedance is maintained.

Abstract: A power amplifier for use in a wireless communication system operates like a quadrature mixer with conversion gain. The amplifier includes a local oscillator that generates two reference signals 90° out of phase with respect to each other. Four quadrature mixer elements receive signals representing the in-phase and quadrature components of a baseband signal. Each quadrature mixer amplifies the in-phase or the quadrature component of the baseband signal while upconverting with the corresponding reference signal.

Abstract: A cordless telephone system connectable to the public switched telephone network having a base station and one or more handsets communicating with the base station by an RF link using a time division duplex direct sequence spread spectrum quadrature modulation technique, having a gain imbalance compensation system for balancing the gain between the I and Q channels. Gain imbalance estimation is performed as part of a calibration cycle when the handset is in the cradle of the base station. The controller of the unit causes another unit to send a data signal with a frequency error. The baseband receiver performs the operation |I|−|Q|, which is an indication of gain error. The results are stored in an accumulator over a set period of time. The controller reads the accumulator and uses an iterative process, increasing or decreasing the gain link compensation until no gain imbalance error is obtained.

Abstract: A signal detector is provided in which correlation analyses of multiple segments of a received signal from separate and distinct periods of time are combined to improve the detection capability of the signal detector. In one embodiment, the signal detector is part of a GPS receiver.

Abstract: A cellular phone for a mobile communications system includes a dual band transmitter which operates at a first radio frequency band and a second radio frequency band. The dual band transmitter includes two amplifiers. The first amplifier has a first input for a first signal at the first radio frequency band, and a first output for an amplified first signal. The first output is connectable to the antenna via a first signal path. The second amplifier has a second input for a second signal at the second radio frequency band and a second output for an amplified second signal. The second output is connectable to the antenna via a second signal path. A filter module is associated with the first and second signal paths and configured to receive a control signal which controls the filter module to have one of a first and second cut-off frequencies.

Abstract: A communications device configured to receive FSK-encoded CLASS caller ID information is also configured to exchange FSK-encoded data with a peer device over a channel previously established between the two devices. In one embodiment, the channel is a voice channel previously established between the two devices.

Abstract: A method and apparatus for estimating signal quality in a direct sequence spread spectrum communication system such as a digital cordless telephone. The method and apparatus beneficially uses data that already available from a window-tracking function used to maintain a demodulation window around the correlation data coming from the system's matched filters. The window-tracking function outputs an in-window peak value and out-window peak value for each bit interval. The signal quality is rapidly and effectively estimated by accumulating the difference between the in-window peak correlation value and the out-window peak correlation value over a period time, preferably for one frame.

Abstract: An ATM system transmits different types of cells (data, forward resource management (RM) and backward RM) from station A through switch(es) to station B. Different fields in an Available Bit Rate (ABR) table provide controls over the rate of such cell transmissions. First particular field values in such table control the selection of successive ones of cell decision blocks which determine the type of cell to be transmitted. Second particular field values in such table control the selection of one of a plurality of entries in an exponent table which also provides other parameter values controlling the generation of an explicit rate. Third particular field values in the ABR table control the selection of an individual one of a plurality of rate decision blocks each indicating an individual rate of cell transmission from the station A to the station B.

Abstract: An analog offset cancellation technique is based on the observation that the voltage developed across an inductor is proportional to the time derivative of the current passing through the inductor. An input voltage that may contain an undesired DC offset voltage is converted to a current that is representative of the input voltage. The resulting input current is passed through an inductor and the voltage generated across the inductor is used as the new input voltage. Because the voltage developed across the inductor is equal to the time derivative of the current passing through the inductor, the resulting voltage, the new input voltage, is independent of any DC components.

Abstract: The invention is directed to multi-line data exchange systems. The invention comprises one or more telephony devices, each coupled to one or more telephone communication lines, such as a standard telephone line, T1 line, T3 line, coaxial cable, or fiber optic line. The telephony devices are equipped with data communication interfaces. These interfaces allow the telephony devices to operate on more than one telephone communication line. The telephone communication lines operate on several bandwidths, including an audio bandwidth. The telephony devices can communicate among themselves apart from the audio bandwidth of the telephone communication lines. When another telephony device is activated or ceases use on one of the telephone communication lines, the telephony devices detect this event and communicate information on the usage of the telephone communication line on the telephone communication lines at a bandwidth other than the audio bandwidth used in voice communications.

Abstract: The present invention provides an efficient method of forwarding and sharing information between functional units and register files in an effort to execute instructions. A digital signal processor includes a plurality of register blocks for storing data operands coupled to a plurality of data path units for executing instructions. Preferably, each register block is coupled to at least two data path units. In addition, the processor preferably has a plurality of forwarding paths which forward information from one data path unit to another. A scheduler efficiently forwards instructions to data path units based on information regarding the configuration of the processor and any restrictions which might be imposed on the scheduler.

Abstract: A signal detector is provided in which complex samples of a received signal are multiplied by data representative of a hypothesis, and the resulting product data is coherently integrated over a desired duration to provide correlation data representative of the level of correlation between the hypothesis and the signal. In one embodiment, the signal detector is part of a GPS receiver.

Abstract: A communications device includes a direct-conversion receiver for a radio frequency (RF) signal which is configured to receive the RF signal during defined time slots. A first input receives the RF signal and a first output outputs a baseband signal derived from the RF signal. A mixer module is configured to receive the RF signal and a local signal which is generated by a local oscillator. The mixer module generates an output signal which includes the baseband signal and an offset component. An amplifier module is connected between the first output and the mixer module, and includes a feedback loop which has in a backward path, a track-and-hold circuit. The track-and-hold circuit is configured to track the offset component during a first time slot and to hold a value of the offset component at an end of the first time slot until a subsequent second time slot begins. This held value is applied during the second time slot to the output signal in order to provide for fast compensation of the offset component.

Abstract: Method and apparatus for plasma etching both metal and inorganic dielectric layers in a single chamber during deep sub-micron semiconductor fabrication. Fluorine based chemistries, or a mixture of fluorine and chlorine based chemistries, are used to etch the inorganic dielectric layer. A switch is then made to chlorine based chemistries, within the same etching chamber, which are utilized to etch the metal layer. Overetching may also be performed with chlorine based chemistries to clear any residuals.

Abstract: A preferred embodiment of a symmetric multiprocessor system includes a switched fabric (switch matrix) for data transfers that provides multiple concurrent buses that enable greatly increased bandwidth between processors and shared memory. A Transaction Controller, Transaction Bus, and Transaction Status Bus are used for serialization, centralized cache control, and highly pipelined address transfers. The shared Transaction Controller serializes transaction requests from Initiator devices that can include CPU/Cache modules and Peripheral Bus modules. The Transaction Bus of an illustrative embodiment is implemented using segmented buses, distributed muxes, point-to-point wiring, and supports transaction processing at a rate of one transaction per clock cycle.