Abstract: A subscriber-line interface circuit (SLIC) has tip and ring amplifiers connected to the tip and ring lines, respectively, of customer premises equipment (CPE). The SLIC returns the ringing signal (provided to the CPE from a power supply connected to the CPE's ring line), to ground or to battery, through the SLIC's tip amplifier. In one embodiment, the SLIC has three switches: S1 connecting the power supply to the ring line, S2 connecting the ring amp to the ring line, and S3 connecting the tip amp to the tip line. During ringing, S1 and S3 are closed to return the ringing signal to ground through the tip amp, which is preferably driven to saturation during ringing to reduce power consumption. By eliminating the fourth switch that appears in prior-art SLICs (e.g., connecting the tip line to ground), SLICs of the present invention can be smaller and therefore less expensive to implement.

Abstract: A demodulation circuit for demodulating a frequency diverse complex modulated carrier comprises an A/D converter generating a series of samples representing the modulated carrier, a mixer operating to mix the series of samples with a sine wave of one fourth the sampling frequency represented by a series of sine wave values occurring at the sampling frequency, and a decimation filter operating at a decimation factor equal to the sampling frequency divided by the frequency difference between adjacent sub-spectra for folding the sub-spectra and retaining a portion of the mixed down series of samples.

Abstract: A computer system that functions as a cordless telephone base unit is disclosed. The computer system includes a cordless telephone device that can be operative through the computer system. The cordless telephone device can function as a cordless telephone base unit with the help of an external antenna that can be attached to the computer system housing. The cordless telephone device may, for example, include a cordless telephone card installed in one of a plurality of connector slots on the computer system motherboard. The cordless telephone device is coupled to a sound device, which may be a computer sound card and may also be installed on the computer system motherboard. The cordless telephone device comprises a cordless telephone base unit, a microphone output and a speaker input to allow the cordless telephone device to be coupled to the sound device in the computer system.

Abstract: A method and apparatus is provided for impedance matching for a system capable of supporting voice and data bands. The method includes receiving an input signal having a voice and data band, filtering at least a portion of the data band of the input signal to provide a filtered signal, and adjusting the impedance of the system for the voice band in response to the filtered signal to provide an output signal.

Abstract: A communications system includes a first modem and a second modem. The first modem is adapted to modulate and demodulate data in accordance with a set of operating parameters and transmit a request to change one of the operating parameters. The second modem is coupled to the first modem and adapted to modulate and demodulate data in accordance with the set of operating parameters, receive the request to change one of the operating parameters, and send a primitive synchronization signal to the first modem. The first modem is adapted to implement the change in response to receiving the primitive synchronization signal. A method for communicating messages requiring synchronization includes receiving symbols in a modem; analyzing the symbols to identify a primitive synchronization signal; and modifying a physical layer operating parameter of the modem in response to identifying the primitive synchronization signal.

Abstract: In its many aspects and variations, a method for accessing a peripheral memory from a processor is provided. The method comprises first initiating the access. Information is then written from the processor to an operational register in a processor memory to enable the peripheral memory. The processor then processes parallel instructions for a predetermined time during which the access occurs. When the access is over, the processor reads the operational register to disable the peripheral memory. In other aspects, an apparatus programmed to perform this method and a program storage medium encoded with instructions that, when executed by a computer, perform the method are provided.

Abstract: A microprocessor including an instruction translation unit and a storage control unit is provided. The instruction translation unit scans the instructions to be executed by the microprocessor. The instructions are coded in the instruction set of a CPU core included within the microprocessor. The instruction translation unit detects code sequences which may be more efficiently executed in a DSP core included within the microprocessor, and translates detected code sequences into one or more DSP instructions. The instruction translation unit conveys the translated code sequences to a storage control unit. The storage control unit stores the code sequences along with the address of the original code sequences. As instructions are fetched, the storage control unit is searched. If a translated code sequence is stored for the instructions being fetched, the translated code sequence is substituted for the code sequence.

Abstract: The present invention comprises an improved telephone system and method that determine the identity of the callee of an incoming telephone call. A distinctive ring is selected by one or more of the users of the telephone prior to activating the feature or at a later time. Information about the individual distinctive ring signals is stored in memory inside the telephone. When an incoming call is received from an external party, the telephone determines which one of the users is the callee of the telephone call. A distinctive ring signal is then generated corresponding to the identified callee of the incoming telephone call. The distinctive ring signal identifies the callee of the incoming telephone call to the telephone users. In order to identify the callee of the incoming telephone call, the telephone system, after answering the incoming telephone call, inquires the caller for the identity of the callee. In another embodiment, a callee is identified using voice recognition techniques.

Abstract: An apparatus for detecting at least one tone having a known frequency and duration in an input signal. The input signal is input over a period of time which is divided into frame portions including at least an initial frame portion and a last frame portion. An energy signal indicative of the energy of the input signal during each frame portion is generated. A signal filter receives the energy signal and generates a noise indicator for each frame portion based on whether noise is detected in the energy signal. A dynamic threshold determiner generates an energy threshold for each frame portion. The energy threshold for the initial frame portion is generated based on a minimum expected value of the energy signal for a subsequent frame portion. The energy thresholds for frame portions subsequent to the initial frame portion are generated based on values of the energy signals during previous frame portions and the noise indicator.

Abstract: A method and apparatus are provided for generating comfort noise in a communication device. The method includes receiving a signal, scaling the signal to a preselected value, indicating whether an error occurred during transmission of the signal, and providing the scaled signal as an output signal in response to receiving the indication that the error occurred during transmission. The apparatus includes a scaler for receiving a signal and being capable of scaling the signal to a preselected value. The apparatus includes an indicator capable of indicating that an error occurred during transmission of the signal, wherein the scaled signal is provided as an output signal in response to an indication that the error occurred during transmission.

Abstract: The present invention comprises an improved telephone system and method that reduce call interruptions to a telephone, i.e., reduce interruptions caused by a caller placing a call to the telephone. If the no-call feature is enabled and a call is received by the telephone, the telephone answers the incoming telephone call in response to receiving the telephone call. The telephone then plays a message to the caller indicating that no calls are being taken. The telephone plays the message after the telephone answers the incoming telephone call. The telephone does not generate an audible ring signal in response to the telephone call received from the caller. The telephone system further comprises an exemption logic unit for allowing calls placed by certain callers to come through even when the no-call feature is enabled. The user indicates the exception parties to the no-call feature prior to receiving a call from an external party or at a later time.

Abstract: A method and apparatus is provided for adjusting DC feed control of a connection. The method includes receiving a signal from the connection and determining if the change in the signal is greater than a first preselected value. The method further includes adjusting the DC feed in response to determining that the change in the signal is greater than the first preselected value.

Abstract: A method and system for improved detection of analog signals, where the analog signals may be composed of one or more analog frequencies. In the method and system, an analog signal is received. A stream of data samples is created from the analog signal. Based on the stream of data samples, a confidence factor regarding the presence of the one or more analog signals is created. The confidence factor is created based upon a confidence factor calculated for each of the one or more analog frequency signals. The confidence factor calculated for each of the one or more analog frequency signals is calculated utilizing incremental energies associated with each of the one or more analog frequency signals.

Abstract: A line card for interfacing with a plurality of subscriber lines includes a plurality of data processors and a tone detector. Each of the data processors is associated with one of the subscriber lines. The tone detector is adapted to detect one of a plurality of activation tones on a selected subscriber line. The plurality of activation tones include a first activation tone having an active portion and a silent portion. The active and silent portions repeat periodically at a first frequency having a first period. A second activation tone has a phase reversal portion repeating at a second frequency and having a second period. The tone detector is further adapted to sequence between the subscriber lines at a predetermined interval. The predetermined interval is based on the first and second periods. The tone detector is adapted to signal the data processor associated with the selected subscriber line in response to detecting one of the activation tones.

Abstract: An amplifier having an improved output current drive capability includes an input stage and an output stage. An input of the output stage is operatively coupled to an output of the input stage. The amplifier further includes a current regeneration circuit operatively coupled to the input of the output stage in a feedback arrangement, the current regeneration circuit feeding back a current to the output circuit in accordance with a predetermined scale factor, the fed back current being proportional to an input current supplied to the output stage. The input current supplied to the output stage is dynamically adjustable by the current regeneration circuit in response to an input current requirement at the output stage.

Abstract: A method for selecting a decimation phase of a decimation filter includes determining a phase strength value for each phase of a plurality of phases. The quantity of phases corresponds to the decimation factor of the decimation filter. The phase strength value for a particular phase group may be representative of the sum of the magnitudes of a plurality of phase values in such particular phase group. The phase strength value for a particular phase group may represent the sum of the squares of a plurality of phase values in the group. The phase of the decimation filter is set to retain the phase with the greatest phase strength value and to filter, or decimate, the other phases.

Abstract: A signal processor includes an adaptive filter that generates an output signal as a function of an input signal and of weighting coefficients stored in a memory. An error detector generates an error signal as a function of the output signal. The error signal is used in adjusting the weighting coefficients. A data processor adjusts the number of weighting coefficients of the adaptive filter and system resources used for storing the weighting coefficients as a function of a characteristic of the weighting coefficients.

Abstract: A method and apparatus are provided, where the method includes defining a first portion of a memory for receiving data, providing a memory request to transfer data from a source to the first portion of the memory defined to receive the data, and transferring a portion of data from the source to the first portion of the memory according to a priority scheme that determines the sequence of the data transfer, wherein the size of the portion of the data substantially corresponds to the size of the first portion of the memory. The method also includes associating a frame with at least one corresponding memory location containing data in the first portion of the memory, transmitting at least a portion of data from the first portion of the memory within the frame, and receiving an acknowledgement in response to transmitting the data within the frame.

Abstract: A method and apparatus are provided. The method includes providing an enable signal to a configuration device for generating a preselected signal, providing the preselected signal to a peer station over a subscriber line, and adjusting a transmission path of a signal to the peer station through the subscriber line in response to the preselected signal.

Abstract: A communications system includes first and second subscriber lines, a first device, and a second device. The first device has a first negotiation unit coupled to the first subscriber line. The second device has a second negotiation unit coupled to the second subscriber line. The first negotiation unit is adapted to send a first negotiation signal on the first subscriber line. The first negotiation signal induces through cross-talk a second negotiation signal on the second subscriber line. The second negotiation unit is adapted to modify an operating parameter of the second device based on the second negotiation signal. A method for negotiating operating parameters in a communications system is provided. A first negotiation signal is transmitted from a first device coupled to a first subscriber line. The first negotiation signal is received in a second device coupled to a second subscriber line independent of the first subscriber line.