Abstract: A circuit for processing radio frequency signals. The circuit includes a substrate where the circuit can be placed. The substrate can be a meta-material and can incorporate at least one dielectric layer. A four port circuit and at least one ground can be coupled to the substrate. The dielectric layer can include a first region with a first set of substrate properties and a second region with a second set of substrate properties. Substrate properties can include permittivity and permeability. A substantial portion of the four port circuit can be coupled to the second region. The permittivity and/or permeability of the second region can be higher than the permittivity and/or permeability of the first region. The increased permittivities and/or permeabilities can reduce a size of the four port circuit and effect a change in a variety of electrical characteristics associated with the four port circuit.
Abstract: A module standard for FPGAs is provided in which power supply voltages for daughtercards are not fixed in advance. Instead programmable power supplies are provided and a method is provided in which each daughtercard can specify the required power supply voltage. Thus, unlike prior-art systems, this modular system is backward and forward compatible with FPGA chips from many process generations allowing easy upgrading as new FPGA families become available. A motherboard or baseboard for use with this invention includes a plurality of module connectors into which compatible modules or “daughtercards” can be plugged and a plurality of programmable power supplies. In a preferred embodiment there are four sets of module connectors and sixteen programmable power supplies. This allows each module to have four independently specifiable power supply voltages. A module may also connect several power supplies together in order to obtain higher current at a single voltage.
Abstract: A transceiver driver for shaping an output signal includes one or more capacitive elements designed to manipulate the current applied to the control node of the driver's output transistor. The capacitive elements may be one or more capacitors coupled to an inverter branch that provides turn-on and turn-off potential to the gate of the output transistor. The capacitive elements act to charge or discharge the transistor's gate gradual in a highly programmable way so as to make the driver substantially independent of fabrication, supply voltage, and operating temperature vagaries.
Abstract: An input buffer is discussed that inhibits semiconductor breakdown of thin gate-oxide transistors in low-voltage integrated circuits. One aspect of the input buffer includes an input stage having a gate, a drain, and a source. The gate of the input stage is receptive to an inhibiting signal, and the drain is receptive to an input signal. The input stage inhibits the input signal from being presented at the source of the input stage when the inhibiting signal is at a predetermined level. The input buffer further includes an output stage having an inverter that includes a first connection and a second connection. The first connection couples to the source of the input stage, and the second connection presents the input signal to a low-voltage flash memory device.
Abstract: In a semiconductor integrated circuit having an LVT (low threshold voltage) block and an HVT (high threshold voltage) block, a power switch controls power supply to the LVT block. An output wrapper fixes a level of an output signal from the LVT block to a predetermined level when no power is supplied to the LVT block, and an input wrapper fixes a level of an input voltage inputted into the LVT block to a predetermined level when no power is supplied to the LVT block. As a result, low current consumption can be realized and malfunctions can be prevented in a power-down mode.
Abstract: A circuit configuration for enabling a clock signal in a manner dependent on an enable signal has first and second signal paths that are fed to a NAND gate. The second signal path contains an RS flip-flop, upstream of which NAND gates are connected, which, for their part, are connected via different inverters to the input terminals for the clock signal and the enable signal, respectively.
Abstract: Controlling the slew rate of a driver circuit. According to one embodiment of the present invention an output buffer includes a driver circuit having an impedance and a pre-driver circuit to control a slew rate of the driver circuit based on the impedance of the driver circuit.
Abstract: A global clock self-timed circuit initiates a precharge pulse in response to which a domino node is precharged. A self-terminating precharge circuit coupled to the global clock self-timed circuit and the domino node terminates the precharge pulse after the domino node has been precharged.
June 30, 2000
Date of Patent:
March 11, 2003
Mark S. Milshtein, Milo D. Sprague, Terry I. Chappell, Thomas D. Fletcher
Abstract: An asynchronous SFQ logic cell that is amenable to being used in combinational logic circuits. Rather than encode each digital logic bit as one SFQ pulse, each logic bit is encoded as a series of SFQ pulses. As such, merge and join circuits can be used for elementary logic cells to form asynchronous combinational logic circuits in accordance with the present invention. Such circuits are relatively faster and denser as well as more compatible with existing synchronous SFQ logic circuits.
Abstract: A semiconductor integrated circuit device has a plurality of basic cells. The basic cells are placed in a matrix form, and are formed on a semiconductor substrate. Each of the basic cells includes a wire selection portion and a logic gate portion. The logic gate portion has a MOS transistor. The wire selection portion has a thin-film transistor serving as a transfer gate. The wire selection portion is placed over the logic gate portion via an interlayer insulating film.
Abstract: A programmable logic array is provided. The programmable logic array includes first and second logic planes. The first logic plane receives a number of input signals. The first logic plane includes a plurality of vertical transistors arranged in rows and columns that are interconnected to provide a number of logical outputs. The second logic plane also includes a number of vertical transistors arranged in rows and columns that receive the outputs of the first logic plane and that are interconnected to produce a number of logical outputs such that the programmable logic array implements a logical function.
Abstract: An active termination circuit for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. The active termination circuit includes a bottom clamping transistor having a bottom clamping transistor first node coupled to a transmission line at a transmission line node, a bottom clamping transistor second node coupled to a first potential, and a bottom clamping transistor control node coupled to a first bias voltage supply. The circuit also includes a top clamping transistor having a top clamping transistor first node coupled to the transmission line at the transmission line node, a top clamping transistor second node coupled to a second potential, and a top clamping transistor control node coupled to a second bias voltage supply.
Abstract: A backplane of a data processing system is configured to include a current boost circuit for each net. The boost circuit is coupled to a common point for the net and is triggered to provide a boost current in response to a detected change in a signal on the net. The boost circuit has the capacity to provide a considerably larger drive current than does the conventional driver on the circuit board connected to the backplane. Thus when a conventional driver starts to drive a signal on the net from one logic state to the other, the boost circuit detects the initiation of change and supplies a boost current to cause a rapid change in logic state. Preferably each terminal on the net is coupled to the common point by a trace which includes both a highly conductive portion and a portion including a damping impedance. The damping impedance is chosen to approximate the characteristic impedance of the trace coupling the terminal to the common point and the associated loading of that trace.
Abstract: A method is provided for selecting a participant to issue. The method includes signaling a domino OR gate arbitration device upon a ready request of a participant having a priority, determining within the domino OR gate arbitration device the relative priority of the participant, signaling the domino OR gate arbitration device through an any-request device upon the ready request of a higher priority participant, and issuing the higher priority participant upon determining the higher priority participant to have a priority highest among participants ready for issue. The method includes gating one of a precharge signal and an evaluate signal of the precharged domino OR gate arbitration device by the ready request of the participant. The method further includes latching a result of the domino OR gate arbitration device and a clock signal, and gating the clock signal by the ready signal of the participant.
August 20, 2001
Date of Patent:
January 28, 2003
International Business Machines Corporation
Hans M. Jacobson, Prabhakar N. Kudva, Peter W. Cook, Stanley Everett Schuster
Abstract: A wide input programmable logic system includes a plurality of logic gates that receive a plurality of row driver signals and memory cell outputs to generate a plurality of logical NOR or NAND outputs for their respective one of said row driver signals and memory cell outputs that are programmed. At least one additional stage of logic gates having a plurality of logical NAND or NOR gates receive the respective logical NOR or NAND outputs and generate a plurality of respective logical NAND or NOR outputs. At least one respective logical NOR or NAND gate receives the respective plurality of logical NAND or NOR outputs and generates an output term. The memory cell may include an electrically erasable non-volatile memory cell having a storage cell that stores a logical value and a select transistor coupled to the storage cell.
Abstract: A segmented digital-to-analog converter circuit employs a tri-level technique to provide an output current in response to a bit code. DAC slice circuits are activated in unary fashion in response to their respective control signal, which are provided by a decoder circuit in response to the high-order bits. Each DAC slice circuit provides a binary weighted current to a summing node in response to the middle-order bits. One of the DAC slice circuits is selected to direct a portion of its total current to the input of a DAC_LOW circuit, where the input current is divided to provide a divided current to the summing node in response to the low-order bits. At certain code transitions a different DAC slice circuit is selected to provide the input current, and the previously selected DAC slice circuit redirects its total current to the summing node such that differential non-linearity errors are minimized.
Abstract: An architecture and distributed hierarchical interconnect scheme for field programmable gate arrays (FPGAs). The FPGA is comprised of a number of cells which perform logical functions on input signals. Programmable intraconnections provide connectability between each output of a cell belonging to a logical cluster to at least one input of each of the other cells belonging to that logical cluster. A set of programmable block connectors are used to provide connectability between logical clusters of cells and accessibility to the hierarchical routing network. An uniformly distributed first layer of routing network lines is used to provide connections amongst sets of block connectors. An uniformly distributed second layer of routing network lines is implemented to provide connectability between different first layers of routing network lines. Switching networks are used to provide connectability between the block connectors and routing network lines corresponding to the first layer.
Abstract: A clipping and quantization technique is described for producing clipped numbers in a range of 0 to N−1 (from unclipped numbers in a range of −0.5N to (1.5N−1)), where N is 2m and m is the bit length of the desired clipped and quantized number. The most significant bit of the unclipped data value indicates whether an overflow of the permitted range has occurred and that clipping is required. The next most significant bit (m−1th) indicates which saturated value should be adopted. These properties of the unclipped data value may be exploited to generate the desired clipped and quantized numbers using logical left shifting and conditionally executed saturating instructions executing upon a general purpose processor 24. The shifting operations performed to achieve saturation operation may simultaneously yield quantization.
Abstract: Method for adjusting the filter characteristic of a microwave ceramic filter which has coupled ceramic resonators, that are ceramic resonators configured in a ceramic body, varies the distance between input/output connections and a grounding connection.
Abstract: A CMOS circuit maintains a constant slew rate over a range of environmental or process conditions. The circuit includes an output stage having a slew rate that is a function of the switching characteristic of the output stage and a bias current. A current adjustment stage adjusts the bias current in view of the switching characteristic to maintain a substantially constant slew rate. The slew rate of the output stage may be tuned to a desired level. A clamp may also be used to limit the voltage variations at the output stage.