Abstract: A complex filter such as the channel select filter in a radio transceiver is implemented using a transconductance/C topology to benefit from the ability to tune such filters and thereby stabilize the output transfer function of the filter over variations in temperature, power supply voltage and process. The topology is based on an active R/C biquadratic topology to achieve the additional benefit of independently controlled stages. The problem created by the R in the output impedance is can be overcome by separately tuning the R value along with the transconductance/C ratio, by implementing the R as a transconductance amplifier having common mode feedback, or by implementing the transconductance amplifiers of the topology using Nauta transconductors, and unbalancing the common mode circuit of the Nauta transconductor to achieve a differential resistance that can be used to implement the R in the output impedance.

Abstract: A low noise transconductance cell includes a resistor and a differential circuit pair having two equivalent half-circuits. Each half-circuit includes a feedback loop coupled to the resistor. The feedback loop includes an input transistor coupled to an inverting gain stage. The inverting gain stage is coupled to an output transistor which in turn is coupled to the input transistor and the resistor. In a low noise transconductance cell, a bias current source is coupled to the center of series connected resistors. In a high swing transconductance cell, a first bias current source is coupled to the left terminal of a resistance stage and a second bias current source is coupled to the right terminal of the resistance stage. The resistance stage can include a single resistor or a plurality of resistors.

Abstract: A decoder having a memory structure which receives and stores potential symbols, with each of the potential symbols having a unique pointer associated therewith. One of the potential symbols is a most likely symbol. The most likely symbol is selected using a pointer selector which processes the unique pointers according to a predetermined selection operation and selects the most likely pointer which, in turn, is uniquely associated with the most likely symbol. The most likely pointer then is used to produce the most likely symbol. The pointer selector is a shuffle exchange network and the predetermined selection operation is a shuffle-exchange operation. The decoder can be used in systems that conform to IEEE Standard 802.3ab, e.g., gigabit Ethernet systems. The potential symbols are four-dimensional, 12-bit symbols having eight symbol states. The memory structure and pointer selector can be constituent of a maximum likelihood decoder, for example a trellis decoder, more specifically a Viterbi decoder.

Abstract: System for measuring a thickness of a circuit component on a printed circuit board (PCB). The system includes a first circuit, a power plane, a power strip, a calibration strip, a temperature sensor, and a second circuit. The power plane is coupled to the first circuit. The power strip is for providing power to the power plane and is disposed in the PCB connected to the power plane. The power strip has at least two vias. The calibration strip has a predetermined width and is disposed in said PCB. The calibration strip has at least two vias for measuring a voltage drop. The temperature sensor is coupled to the calibration strip and configured to measuring a temperature of the calibration strip. The second circuit is coupled to the temperature sensor and configured to determine the thickness of the calibration strip based on at least the temperature of the calibration strip.

Abstract: A one-time-programmable (OTP) module includes OTP memory and OTP input/output (I/O) that performs error correction operations. The OTP module may be used in a data communications system. The error correction operations operate according to one of a plurality of supported coding schemes. In one embodiment, the error correction operations are based upon Hamming code operations. The coding scheme employed by the error correction operations is set by a code control input. The code control input is chosen based upon the inherent quality of the OTP memory. The OTP module may thus be incorporated into any of a variety of processes, each of which has its own OTP memory quality.

Abstract: A method and apparatus for storing data, the method including the steps of generating a glitchless fractional clock pulse in a circuit and transmitting the glitchless fractional clock pulse from the circuit to a data storage element. The data storage element thereafter stores data in the storage element upon receiving the glitchless fractional clock pulse. The apparatus for storing data includes at least one storage element having a data input, a storage enable input, and a data output, and at least one logic circuit having an activating input, an clock input, and a logic output. The at least one logic circuit generates a glitchless fractional clock pulse on the logic output, wherein the logic output is connected to the storage enable input of the storage element and operating to enable the at least one storage element to store data resident on the data input at an optimally stable time.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, and graphics input. The chip blends graphics and video information by various graphics windows using alpha values for the windows, alpha values per pixel, or both. The chip calculates a composite alpha value based on the window's alpha values and the alpha values per pixel. Blended graphics and video may then be composited using the composite alpha value.

Abstract: A method and apparatus are disclosed for efficiently doubling a first frequency of a first clock signal. A second clock signal at a second frequency is generated by dividing the first frequency of the first clock signal by two, such that the second frequency is half of the first frequency and a duty cycle of the second clock signal is 50%. Also, a set of phase-delayed clock signals is generated in response to the second clock signal such that the set of phase-delayed clock signals are delayed in phase with respect to the second clock signal. Further, the set of phase-delayed clock signals is combined to generate a third clock signal at a third frequency, such that the third frequency is twice that of the first frequency and a duty cycle of the third clock signal is 50%.

Abstract: A system comprises a plurality of nodes, each node comprising one or more coherent agents coupled to an interconnect. Ownership of a coherency block accessed by a transaction on the interconnect is transferred responsive to transmission of the address on the interconnect. The system further includes a second interconnect to which the plurality of nodes are coupled, wherein ownership of a coherency block is transferred on the second interconnect responsive to a transmission of the data comprising the coherency block on the second interconnect. A first node of the plurality of nodes issues a coherency command on the second interconnect to fetch the coherency block in response to the transaction on the interconnect within the first node, whereby ownership transfers within the first node prior to ownership transferring from another one of the plurality of nodes to the first node.

Abstract: An apparatus for providing bias voltages for input/output (I/O) connections on low voltage integrated circuits. In one embodiment, the invention comprises an I/O pad, a pull-down transistor device that has a protective transistor coupled to said I/O pad, and a pull-up transistor device that has a second protective transistor, coupled to said I/O pad. A first switch coupled to the first protective transistor is responsive to a first supply voltage, a second supply voltage, and a reference voltage. Likewise, a second switch coupled to the second protective transistor is responsive to the first supply voltage and the reference voltage. A first self-bias circuit is also coupled to the first switch, wherein said the self-bias circuit uses a voltage at said I/O pad to bias the first protective transistor when both of the first and second supply voltages are powered off.

Abstract: A method and system for connecting multiple initiators to a storage area network (SAN) via a Fibre channel fabric using a single N_port fibre channel switch. The multiple initiators are associated with a common domain identification (DID), each initiator having a unique source identification (SID). The method includes initiating a communication exchange between at least one of the initiators and the SAN, the exchange including transmission of a command frame. The method also includes monitoring the initiated exchange communication exchange, and replacing the unique SID of one of the initiators with an SID of the fibre channel switch.

Abstract: The present invention enables the coupling and decoupling of multiple processing devices to a network without disrupting the network. In an embodiment, the invention provides a switch having a network port and several initiator ports each configured for coupling to a processing device. The switch is configured to route data from the network port to the initiator ports and from the initiator ports to the network port. A management agent facilitates operation of the switch by processing port initializations, replying to device registration requests, and processing predetermined unsolicited discovery commands. During operation, the management agent enables configuration changes caused, for example, by the coupling and/or decoupling of processing device to initiator ports. Each processing device coupled to one of the initiator ports operates without knowledge of the management agent, as if coupled directly to the network.

Abstract: A method and system for allocating exchange identifications (IDs) in a fibre channel switch for fibre channel aggregation. The method included determining a number (m) of N_ports present in a back end of the switch, and distributing available exchange IDs across the number (m) of present N_ports. Each exchange ID includes (j) bits and (n) bits are used to identify each of the present backend ports, where m?2n.

Abstract: The present invention enables the coupling and decoupling of multiple processing devices to a network without disrupting the network. In an embodiment, the invention provides a switch having a network port and several initiator ports each configured for coupling to a processing device. The switch is configured to route data from the network port to the initiator ports and from the initiator ports to the network port. A management agent facilitates operation of the switch by processing port initializations, replying to device registration requests, and processing predetermined unsolicited discovery commands. During operation, the management agent enables configuration changes caused, for example, by the coupling and/or decoupling of processing device to initiator ports.

Abstract: The present invention includes operational amplifier for an active pixel sensor that detects optical energy and generates an analog output that is proportional to the optical energy. The active pixel sensor operates in a number of different modes including: signal integration mode, the reset integration mode, column reset mode, and column signal readout mode. Each mode causes the operational amplifier to see a different output load. Accordingly, the operational amplifier includes a variable feedback circuit to provide compensation that provides sufficient amplifier stability for each operating mode of the active pixel sensor. For instance, the operational amplifier includes a bank of feedback capacitors, one or more of which are selected based on the operating mode to provide sufficient phase margin for stability, but also considering gain and bandwidth requirements of the operating mode.

Abstract: Interchangeable integrated circuit building blocks include functionally equivalent integrated circuit building blocks, having similar footprints, and having one or more dissimilar features or operational characteristics. The functionally equivalent integrated circuit building blocks are interchangeable in a design layout without having to re-place and re-route. The functionally equivalent integrated circuit building blocks are optionally interchangeable on a building block by building block basis. One or more detection features are optionally included in one or more of the interchangeable integrated circuit building blocks. The detection features facilitate detection of the interchangeable integrated circuit building blocks. Area, space, and/or width design rule checks are optionally focused at junctions of detected integrated circuit building blocks.

Abstract: A digital high frequency power detection circuit includes a peak detecting circuit and a peak computing circuit. The peak detecting circuit is operably coupled to detect a peak value of a high frequency signal and includes an amplifier, transistor, and capacitor. The amplifier has a 1st input, 2nd input and an output, where the 1st input is operably coupled to receive the high frequency signal. The transistor has a gate, a drain, and a source, where the gate is coupled to the output of the amplifier, the source is coupled to a supply voltage, and the drain is coupled to the 2nd input of the amplifier. The capacitor is operably coupled to the drain of the transistor and to a reference potential. The voltage imposed across the capacitor represents the peak value of the high frequency signal. The peak computing circuit is operably coupled to generate a digital peak value from the peak value.

Abstract: A random number generator circuit includes a primary circuit configured to generate a value within a first range and a secondary circuit configured to generate a value within a second range. A detector circuit detects whether or not the value from the primary circuit is within the desired output range for the random number generator circuit, and selects either the value from the primary circuit or the value from the secondary circuit in response. The second range is the desired output range and the first range encompasses the second range. In one embodiment, the primary circuit has complex harmonics but may generate values outside the desired range. The secondary circuit may have less complex harmonics, but may generate values only within the desired range. In one implementation, the random number generator circuit is used to generate a replacement way for a cache.

Abstract: A method for calibrating a phase locked loop begins by determining a gain offset of a voltage controlled oscillator of the phase locked loop. The processing then continues by adjusting current of a charge pump of the phase locked loop based on the gain offset.

Abstract: A power amplifier includes a transconductance stage, a cascode stage, and a connector. The transconductance stage is operable to receive an input voltage signal and to produce an output current signal. The cascode stage communicatively couples to the transconductance stage and is operable to receive the output current signal and to produce an output voltage signal based thereupon. The cascode stage includes a Metal Oxide Silicon (MOS) transistor and a corresponding parasitic bipolar transistor formed in parallel therewith in a semi conductive substrate. The MOS transistor has a drain, a gate, and a source. The corresponding parasitic bipolar junction transistor has a collector corresponding to the drain, an emitter corresponding to the source, and a base corresponding to the semi conductive substrate. The connector couples the base of the corresponding parasitic bipolar junction transistor to the source of the MOS transistor.