An impedance warping circuit (IWC) and technique for compensating the effect of a blocking capacitor within a transformer of an interface circuit for passing plain old telephone service (POTS) band and asynchronous digital subscriber line (ADSL) band signals on signals having frequencies in the POTS band. The IWC does not significantly affect the performance of the interface circuit in the ADSL band. The IWC synthesizes impedance to compensate the frequency-dependent deviation in the termination...

A programmable logic device (PLD) having a programmable routing structure that employs non-static memory cells, such as dynamic random access memory (DRAM) cells, to control configurable circuit elements, such as pass-transistors and/or MUXes. In a representative embodiment, each DRAM cell is connected to its corresponding configurable circuit element using a buffer adapted to stabilize the output voltage generated by the cell and offset the effect of charge leakage from the cell capacitor. In a...

A general test application scheme is proposed for existing scan-based BIST architectures. The objective is to further improve the test quality without inserting additional logic to the Circuit Under Test (CUT). The proposed test scheme divides the entire test process into multiple test sessions. A different number of capture cycles is applied after scanning in a test pattern in each test session to maximize the fault detection for a distinct subset of faults. A procedure is presented to find the...

A turbo encoder includes a memory for temporarily storing an incoming data sequence and an interleaved address generator (IAG) designed to generate a sequence of addresses corresponding to the interleaved data sequence. The IAG performs calculations based on the length of the incoming data sequence and is able to generate a first interleaved address by (or before) the time the incoming data sequence has completely shifted into the memory. As a result, the encoder begins to output encoded data su...

A capacitor cancellation method and apparatus for use in an interface circuit having a transformer blocking capacitor. The method includes sensing a voltage across the transformer blocking capacitor and generating a cancellation signal to compensate for the effect of the transformer blocking capacitor. The apparatus includes a sensor to sense a differential voltage across the transformer blocking capacitor to develop a capacitor signal and an amplifier to amplify the capacitor signal to obtain a...

A method for locating a mobile unit without synchronizing base-stations is provided. A triangulation scheme where distances between a plurality of base-stations and a mobile unit (herein termed mobile) are calculated by measuring at least three round-trip-delay-values wherein each round-trip-delay-value corresponds to transmission of a downlink signal from each base-station to the mobile unit and transmission of an uplink signal, in response to the downlink signal, from the mobile unit to each b...

A phase-modulated signal such as a quadrature phase-shift-keyed (QPSK) signal in a wireless communication system is demodulated by frequency demodulating the phase-modulated signal. The phase-modulated signal is separated into first and second copies, the first copy is phase demodulated to generate demodulated symbols, and the second copy is frequency demodulated to generate, e.g., a measure of the instantaneous frequency of the phase-modulated signal. The instantaneous frequency measure is proc...

A duobinary modulator and a method of modulating an optical signal so as to be coded in a duobinary manner, using optical modulating specifically adapted for this purpose is provided. Two input electrical signals are respectively input to two binary encoders. The binary encoders encode the input electrical signals and generate a pair of encoded binary signals which are then input to an analog amplifier. The analog amplifier amplifies the encoded binary signals and generates a pair of duobinary s...

An improved method and apparatus for connecting various function modules located within a computer or communications system are proposed. In accordance with the principles of the present invention, a port manager controller (PMC) has a direct interface to each of the function modules and to a host component such as a system memory or a CPU. The PMC replaces both the local bus and the arbitrator of prior art systems. All the requests by function modules to access the host component are first proc...

Method for automatically determining whether a communication trunk is operating properly without having to take the trunk out of service and without the need of a craftsperson to initiate the testing of the communication trunk. The communication trunk is tested for continuity and integrity on a periodic or aperiodic basis.