Abstract: A method and disk drive for calibrating a phase of a clock in the disk drive. The phase of the clock in the disk drive is changed such that a rate of change for the phase is substantially constant. A pattern of data is written to a magnetic material in the disk drive after the rate of change for the phase becomes substantially constant and while changing the phase of the clock. A selected phase of the clock at which the pattern of data that is written on the magnetic material has a desired quality is identified using the rate of change for the phase, a first point in time at which a timing mark on the magnetic material is read, a second point in time at which the timing mark is read, and a third point in time at which the pattern of data has the desired quality.

Abstract: A method and disk drive for calibrating a phase of a clock in the disk drive. The phase of the clock in the disk drive is changed such that a rate of change for the phase is substantially constant. A pattern of data is written to a magnetic material in the disk drive after the rate of change for the phase becomes substantially constant and while changing the phase of the clock. A selected phase of the clock at which the pattern of data that is written on the magnetic material has a desired quality is identified using the rate of change for the phase, a first point in time at which a timing mark on the magnetic material is read, a second point in time at which the timing mark is read, and a third point in time at which the pattern of data has the desired quality.

Abstract: The portion of TDMA frames otherwise containing the sync word is eliminated for one or more data frames at the end of a TDMA data burst to provided added bandwidth for data payload or for a reduced bandwidth. Once a communication channel has been established and is in steady state mode (after receipt of one or more frames), the sync word is eliminated from the remaining frame structure. Drift of a local clock with respect to an incoming data stream is monitored using an oversampled or multiplied master clock to provide suitable resolution to determine an approximate position of an active edge of the master clock with respect to a bit or symbol being clocked. Any drift from center results in an adjustment of the local master clock. In a preferred embodiment, the drift is measured in a last bit or symbol of a received TDMA burst, and the master clock is adjusted to re-center the local master clock with respect to that last bit.

Abstract: In a digital cordless telephone system, a different speech coding scheme is used in the audio path from the base unit to its remote handset than that which is used in the audio path in the opposite direction from the remote handset to the base unit. It is found that this unbalanced coding scheme optimizes overall system cost and performance. In particular, two different types, quality and/or bit rates of speech encoders are implemented in opposite directions of the same full-duplex audio path, providing an unbalanced coding in a digital cordless telephone. Implementation of different types of speech encoders in a common full duplex path optimizes system cost and performance. It is recognized by the invention that the communications link in a first direction from a base unit to its remote handset in a digital cordless telephone system potentially requires better codec and audio performance than the communications link in the opposite direction from the remote handset to base unit.

Abstract: A method and apparatus for converting a full-rate digital clock circuit to a fractional-rate clock circuit. The combinatorial and sequential functions of the full rate design are duplicated, with a first combinatorial function responsive to even input logic vectors and a second combinatorial function responsive to odd input logic vectors. Output vectors from the first and the second combinatorial function are provided as input vectors to the respective first and second sequential function, which operate at a fractional clock rate and provide the output block vectors.

Abstract: A frequency hopping spread spectrum cordless telephone system which arranges a swap table. The method and apparatus scans the electromagnetic interference energy content of the frequencies listed in the swap table, for example, when the base unit and hand-held unit are not in use. A controller thereafter arranges the frequencies in the swap table according to their respective electromagnetic interference energy content. During normal operation, upon detection of a degraded active or hop frequency, the controller selects the swap frequency with the lowest electromagnetic interference energy content, which preferably is in the first position in the swap table, to replace the degraded hop frequency.

Abstract: A method and apparatus for transferring convenience feature data (e.g., speed dial numbers, etc.) from one telephone to another local telephone within the same home or small office. In particular, the telephone includes a memory located within a corded or cordless telephone configured for storing data, and a transfer module configured to transfer requested data between the memory and a target device in response to a transfer request. The corded telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, or a Bluetooth module to establish a communication path between the corded telephone and the target device. The cordless telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, a radio frequency (RF) transceiver, or a Bluetooth module to establish a communication path between the cordless telephone and the target device.

Abstract: A timing recovery circuit and method which determines whether a sample point in a generated bit sequence is early or late based on binary logic which is already available used in generating a bit sequence by comparing energy magnitudes of adjacent bits. The waveform of an input symbol is correlated against reference waveforms. When the incoming waveform does not perfectly match a reference waveform, symbol energy less than maximum is output indicating that the timing of the sampling points is either early or late. Symbol energy magnitudes between adjacent bits are then compared. Using the bit pattern of the generated bit sequence and the results of comparisons of energy magnitudes of adjacent bits, it is determined whether the timing of the sampling points is early or whether it is late.

Abstract: Systems and methods utilize cradle contacts for completing diagnostic tests of rechargeable devices, such as cordless telephones. A cordless telephone handset or base is placed into a test fixture. Once the handset or base is cradled, diagnostic message signals are transmitted through cradle contacts in the test fixture and handset/base. The message signals may be made up of ASK signals. The beginning and end of each test may be identified by a code or codes embedded in a message signal. The use of cradle contacts to complete diagnostic tests alleviates problems associated with use of internal test access ports to carry out such tests.

Abstract: The portion of TDMA frames otherwise containing the sync word is eliminated for one or more data frames at the end of a TDMA data burst to provided added bandwidth for data payload or for a reduced bandwidth. Once a communication channel has been established and is in steady state mode (after receipt of one or more frames), the sync word is eliminated from the remaining frame structure. Drift of a local clock with respect to an incoming data stream is monitored using an oversampled or multiplied master clock to provide suitable resolution to determine an approximate position of an active edge of the master clock with respect to a bit or symbol being clocked. Any drift from center results in an adjustment of the local master clock. In a preferred embodiment, the drift is measured in a last bit or symbol of a received TDMA burst, and the master clock is adjusted to re-center the local master clock with respect to that last bit.

Abstract: A multiple handset cordless telephone includes a Caller ID/handset association table to identify a desired intended handset to receive an incoming call before the call is answered. When a match is made as between received call related information and a pre-stored entry in the Caller ID/handset association table, one or more intended handsets are provided with the subsequent ring signals and/or the subsequent voice conversation. If no match is found the cordless telephone operates otherwise in conventional fashion, i.e., all handsets ring in response to the incoming call, and any or all of the handsets may join the conversation at any time.

Abstract: A method and apparatus for transferring convenience feature data (e.g., speed dial numbers, etc.) from one telephone to another local telephone within the same home or small office. In particular, the telephone includes a memory located within a corded or cordless telephone configured for storing data, and a transfer module configured to transfer requested data between the memory and a target device in response to a transfer request. The corded telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, or a Bluetooth module to establish a communication path between the corded telephone and the target device. The cordless telephone utilizes a DTMF generator/receiver, a demodulation/modulation module, a radio frequency (RF) transceiver, or a Bluetooth module to establish a communication path between the cordless telephone and the target device.

Abstract: A glitchless clock switch in accordance with the principles of the present invention avoids the need to directly synchronize clock selection signals with the source clock. Instead, clock switching control signals are generated with relation to Finite-State-Machines (FSMs) for each clock signal. Thus, the cycle relationship of the different clock sources do not affect the clock switching process. The FSM for each clock has three states: ON, STOP, and IDLE. During the switching process, each clock signal enters its respective IDLE state. Detection of the ALL_IDLE state is synchronized with a directly derived signal from the newly selected clock. Any glitches in the switching process are isolated to the control of the synchronization of the ALL_IDLE state, which does not affect the output clock signal.

Abstract: A method of transmitting a voice communications signal includes the steps of sampling the signal and creating digital representations of the samples. The digital representations are speech-coded to create speech-coded data which is converted to analog symbols. A carrier in the 46-49 MHz band is modulated by the analog symbols and transmitted. A method of receiving a voice communications signal includes the steps of receiving a modulated carrier in the 46-49 MHz band and demodulating the modulated carrier to recover analog symbols. The analog symbols are converted to digital samples, which are then converted to speech-coded data. The speech-coded data are decoded to produce digitized samples, which are converted to analog samples and filtered to produce the voice communications signal. A cordless telephone system according to the invention includes a handset and a base unit.

Abstract: A cordless telephone base unit includes a registration unit adapted to selectively register with a handset according to at least one predefined criterion, a call handling unit adapted to handle an incoming call when the handset is registered with the registration unit, and a call forwarding unit adapted to forward an incoming call to a forwarding number when the handset is not registered with the registration unit.

Abstract: In a first embodiment according to the invention, a cordless telephone handset of a cordless telephone system includes a user input unit, a signal processor and an output driver. The signal processor is coupled to the user input unit. The signal processor processes user input received via the user input unit. The output driver receives processed information from the signal processor and selectively outputs the processed information to at least one of a plurality of output devices. For example, in one embodiment the user input unit is a keypad, and the signal processor selectively processes the user input as telephone control information and as television control information. In a second embodiment according to the invention, a method of receiving an incoming call in a cordless telephone includes the steps of receiving an incoming call telephone signal, and outputting a television control signal in response to the incoming call telephone signal.

Abstract: A clock circuit for providing an integrated circuit with a high accuracy, crystal oscillator clock which interfaces to an "off-chip" crystal to provide a high accuracy clock signal while an internal, low power oscillator provides a low power clock source. Either clock may be selected to drive a programmable processor under program control. When high accuracy and stability are required, the crystal oscillator may be chosen as the processor clock, and when lower power is desired, the low power oscillator may be chosen as the processor clock while the high accuracy clock is disabled. The high accuracy oscillator is used to clock a first timer circuit, while the low power oscillator is used to clock a second timer circuit. The second timer circuit output, in turn, is synchronized to the processor clock so that the programmable processor can utilize the second timer circuit even when the processor clock is asynchronous to the second timer circuit.