Abstract: A calibration mechanism is disclosed for performing I/Q mismatch calibration operations in a wireless communication device comprising a receiver unit and a transmitter unit. During an I/Q mismatch calibration mode, a first signal and a second signal are provided from the transmitter unit to the receiver unit via a loopback path coupled between the transmitter and receiver units. A phase shift is added to the second signal that is provided to the receiver unit. A first set of I/Q measurements is determined from the first signal and a second set of I/Q measurements is determined from the second signal with the added phase shift. Transmitter and receiver I/Q mismatch parameters are calculated based on the first and second sets of I/Q measurements. The receiver and transceiver I/Q mismatch parameters are used to compensate for I/Q mismatch at the receiver and transmitter units, respectively.

Abstract: An apparatus for processing a Bluetooth signal advantageously mixes down a received RF signal to an IF signal wherein one band-edge of the spectrum of the IF signal may be approximately 0 Hz. In one embodiment, the IF signal may be digitized, decimated and filtered before being processed into a baseband signal. The baseband signal may be processed by a cordic (COordinate Rotation DIgital Computer) processor to transform the baseband signal from rectangular to polar coordinates. A phase signal from the cordic processor may be used to determine transmitted Bluetooth data symbols. The apparatus may advantageously use less area than traditional Bluetooth receivers.

Abstract: The disclosed invention presents a method and apparatus to a one dimensional prefix search problem. The problem consists looking up the best match to a word out of a table of one-dimensional prefixes. The invention addresses the problems with prior art of high power consumption, large silicon chip area for implementation and slow search speed. The prefix entries are divided in several subgroups. A function is described that can be efficiently implemented to determine which of these subgroups the presented word will find a best match in. Thus, it is necessary to search only this small subgroup of prefixes. This saves on power consumption as well as area. An efficient hardware embodiment of this idea which can search at a very high speed is also presented. The applications for this invention could include internet routing, telephone call routing and string matching.

Abstract: An apparatus and method for producing dummy data is based on timing paths co-located with the address/data paths of the memory. An output clock generator uses the dummy data. The technique for producing dummy data is particularly important for memory systems in which the output of memory cells do not normally provide large voltage swings, making them less practical for self timing approaches to dummy data generation.

Abstract: An apparatus for processing a Bluetooth signal advantageously mixes down a received RF signal to an IF signal wherein one band-edge of the spectrum of the IF signal may be approximately 0 Hz. In one embodiment, the IF signal may be digitized, decimated and filtered before being processed into a baseband signal. The baseband signal may be processed by a cordic (COordinate Rotation DIgital Computer) processor to transform the baseband signal from rectangular to polar coordinates. A phase signal from the cordic processor may be used to determine transmitted Bluetooth data symbols. The apparatus may advantageously use less area than traditional Bluetooth receivers.

Abstract: An output clock for a memory device having a read latency more than one clock cycle includes a clock generator at a central location on the device. A clock channel couples the clock generator to output structures. A timing path emulates the address/data paths in the memory, and is responsive to an address emulation signal produced by the clock generator to provide dummy data near the output structures. An output clock signal with an adjustable phase and a dummy data reference clock signal on the input of the clock channel are generated. A phase detector near the output structures, determines whether the output clock is early, late or on time with respect to the dummy data. Logic signals are produced at the phase detector, and returned to the clock generator for adjusting the relative phase of the output clock signal.

Abstract: A geometric DAC architecture includes a series of substantially identical sub-DACs, each sub-DAC having n taps. The sub-DACs are fed from a bias-DAC having m=(total number of taps needed)/n taps. The output of each of the m taps is increased geometrically at a rate of kn. The geometric DAC architecture control lines desirably require only (m+n) taps compared with (m×n) taps for the simpler more conventional approach. Further, the geometric DAC architecture requires less real estate than the simpler more conventional approach, is easy to expand because it is modular, and generates an output current that is always monotonic, regardless of errors in transistor sizes and PVT variations. The n tap control lines are coded by alternately inverting n control line inputs between sub-DACs such that any state transition associated with the geometric DAC occurs with only one bit change in each of the control lines.

Abstract: A method and apparatus generates output clock pulses, having leading and trailing edges that are adjusted in a pulse forming processor, according to the relative phase of an output clock and output data. Dynamic adjustment of the leading and trailing edges of output clock pulses improves the performance of high-speed devices significantly.

Abstract: The disclosed invention presents a method and apparatus to a one dimensional prefix search problem. The problem consists looking up the best match to a word out of a table of one-dimensional prefixes. The invention addresses the problems with prior art of high power consumption, large silicon chip area for implementation and slow search speed. The prefix entries are divided in several subgroups. A function is described that can be efficiently implemented to determine which of these subgroups the presented word will find a best match in. Thus, it is necessary to search only this small subgroup of prefixes. This saves on power consumption as well as area. An efficient hardware embodiment of this idea which can search at a very high speed is also presented. The applications for this invention could include internet routing, telephone call routing and string matching.

Abstract: A delay line for an adjustable, high speed clock generator is based on two-stage multiplexing, in which for all pairs of adjacent taps, a change from a current tap to an adjacent tap in the pair is executed by switching only one of the first stage and second stage multiplexers. Control signals are generated for the first and second stage multiplexers by logic based on bidirectional shift registers. The delay line is suitable for generation of an output clock having an adjustable phase, allowing for smooth, glitch-free adjustment over a large range of phases.

Abstract: A geometric DAC architecture includes a series of substantially identical sub-DACs, each sub-DAC having n taps. The sub-DACs are fed from a bias-DAC having m=(total number of taps needed)/n taps. The output of each of the m taps is increased geometrically at a rate of kn. The geometric DAC architecture control lines desirably require only (m+n) taps compared with (m×n) taps for the simpler more conventional approach. Further, the geometric DAC architecture requires less real estate than the simpler more conventional approach, is easy to expand because it is modular, and generates an output current that is always monotonic, regardless of errors in transistor sizes and PVT variations. The n tap control lines are coded by alternately inverting n control line inputs between sub-DACs such that any state transition associated with the geometric DAC occurs with only one bit change in each of the control lines.

Abstract: A geometric DAC architecture includes a series of substantially identical sub-DACs, each sub-DAC having n taps. The sub-DACs are fed from a bias-DAC having m=(total number of taps needed)/n taps. The output of each of the m taps is increased geometrically at a rate of kn. The geometric DAC architecture control lines desirably require only (m+n) taps compared with (m×n) taps for the simpler more conventional approach. Further, the geometric DAC architecture requires less real estate than the simpler more conventional approach, is easy to expand because it is modular, and generates an output current that is always monotonic, regardless of errors in transistor sizes and PVT variations. The n tap control lines are coded by alternately inverting n control line inputs between sub-DACs such that any state transition associated with the geometric DAC occurs with only one bit change in each of the control lines.