Abstract: A reconfigurable high performance computer includes a stack of semiconductor substrate assemblies (SSAs). Some SSAs involve FPGA dice that are surface mounted, as bare dice, to a semiconductor substrate. Other SSAs involve memory dice that are surface mounted to a semiconductor substrate. Elastomeric connectors are sandwiched between, and interconnect, adjacent semiconductor substrates proceeding down the stack. Each SSA includes a local defect memory and a self-test mechanism. The self-test mechanism periodically tests the SSA and its interconnects, and stores resulting defect information into its local defect memory. The computer is configured to realize a user design and then is run. A defect is then detected. If the defect is determined to be inma part of the computer used in the realization of user design, then the computer is reconfigured not to use the defective part and running of the computer is resumed, otherwise the computer resumes running without reconfiguration.

Abstract: A reconfigurable high performance computer includes a stack of self-aligning, injection-molded plastic, insulative guide trays. Each insulative guide tray retains at least one semiconductor substrate assembly (SSA) in a lateral dimension with respect to a set of elastomeric connectors. The trays hold the SSAs and the elastomeric connectors such that the elastomeric connectors are sandwiched between, and interconnect, adjacent semiconductor substrates proceeding down the stack. The trays also hold comb-shaped power bus bar assemblies such that power bus bars contact and supply power to circuitry of the SSAs of the stack.

Abstract: A plurality of FPGA dice is disposed upon a semiconductor substrate. In order both to connect thousands of signal interconnect lines between the plurality of FPGA dice and to supply the immense power required, it is desired that the substrate construction include two different portions, each manufactured using incompatible processes. The first portion is a signal interconnect structure containing a thin conductor layers portion characterized as having a plurality of thin, fine-pitch conductors. The second portion is a power connection structure that includes thick conductors and vertical through-holes. The through-holes contain conductive material and supply power to the FPGA dice from power bus bars located at the other side of the semiconductor substrate. The portions are joined at the wafer level by polishing the wafer surfaces within a few atoms of flatness and subsequent cleaning. The portions are then fusion bonded together or combined using an adhesive material.

Abstract: A reconfigurable high performance computer occupies less than 360 cubic inches and has an approximate compute power of 0.7 teraflops per second while consuming less than 1000 watts. The computer includes a novel stack of semiconductor substrate assemblies. Some semiconductor substrate assemblies involve field programmable gate array (FPGA) dice that are directly surface mounted, as bare die, to a semiconductor substrate. Other semiconductor substrate assemblies of the stack involve bare memory integrated circuit dice that are directly surface mounted to a semiconductor substrate. Elastomeric connectors interconnect adjacent semiconductor substrates proceeding down the stack. Tines of novel comb-shaped power bus bar assembly structures extend into the stack to supply DC supply voltages. The supply voltages are supplied from bus bars, through vias in the semiconductor substrates, and to the integrated circuits on the other side of the substrates.

Abstract: A method of operating a programmable logic device, including the steps of using a full VDD supply voltage to operate one or more active blocks of the programmable logic device, and using a reduced supply voltage (e.g., ½ VDD) to operate one or more inactive blocks of the programmable logic device. The full VDD supply voltage and reduced supply voltage can be provided to the blocks of the programmable logic device through high-voltage n-channel transistors. A boosted voltage, greater than VDD, is applied to the gate of an n-channel transistor to provide the full VDD supply voltage to an active block. A standby voltage, less than VDD, is applied to the gate of an n-channel transistor to provide the reduced supply voltage to an inactive block. The inactive blocks can be determined during run time and/or design time of the programmable logic device.

Abstract: A system replicates the rapid temperature increases that are believed to cause microbump failures in certain applications of programmable logic devices (PLDs). The system configures a PLD under test with a circuit that switches a large amount of current and generates a large amount of heat when the circuit is clocked. The system monitors the temperature of the PLD and controls the switching of the circuit to achieve a predetermined temperature within a predetermined time period. The PLD is cooled, and the thermal cycling is repeated. The system detects microbump failures and communicates failure data to a computer for logging and analysis.

Abstract: A method and apparatus are provided for updating or changing configuration data stored in the PROM of a target system, the data being used to configure one or more reprogrammable logic devices such as FPGAs. In one embodiment the apparatus comprises a modem used to communicate remotely with a host system, a shadow PROM for receiving new configuration data intended for use in a target system, an interface for relaying configuration data from the shadow PROM to the target, and means for controlling the components of the update system.

Abstract: A capacitive interposer (caposer) is disposed inside an integrated circuit package between a die and an inside surface of the package. Conductive layers within the caposer constitute a bypass capacitor. In a through-hole caposer, micro-bumps on the die pass through through-holes in the caposer and contact corresponding landing pads on the package. As they pass through the caposer, power and ground micro-bumps make contact with the plates of the bypass capacitor. In a via caposer, power and ground micro-bumps on the die are coupled to power and ground landing pads on the package as well as to the plates of the bypass capacitor by power and ground vias that extend through the caposer. In signal redistribution caposer, conductors within the caposer redistribute signals between die micro-bumps and package landing pads. In an impedance matching caposer, termination structures within the caposer provide impedance matching to a printed circuit board trace.

Abstract: A method of operating a programmable logic device, including the steps of enabling resources of the programmable logic device being used in a circuit design implemented by the programmable logic device, and disabling unused or inactive resources of the programmable logic device that are not being used in the circuit design. The step of disabling can include de-coupling the unused or inactive resources from one or more power supply terminals. Alternatively, the step of disabling can include regulating a supply voltage applied to the unused or inactive resources. The step of disabling can be performed in response to configuration data bits stored by the programmable logic device and/or in response to user controlled signals. The step of disabling can be initiated during design time and/or run time of the programmable logic device.

Abstract: An integrated circuit die contains digital circuitry that emits noise (for example, in the audio frequency range) in the form of electromagnetic radiation. The integrated circuit die is provided with a shielded platform above the digital circuitry. The shielded platform has one metal plate that is coupled to an analog supply voltage source and another metal plate that is coupled to an analog ground terminal. The digital circuitry is coupled to a digital supply voltage source. A second die with noise-sensitive analog circuitry is stacked on the shielded platform and is shielded by the shielded platform from the noise. The analog circuitry is powered by the analog supply voltage source. Conductive vias in a predetermined pattern protrude through the shielded platform and provide a standardized way of connecting any one of numerous noise-sensitive second dice to the relatively noisy digital circuitry of the underlying die.

Abstract: A general purpose interface tile of a first integrated circuit includes a plurality of micropads. A second integrated circuit may be stacked on the first integrated circuit such that signals from the second integrated circuit are communicated through the micropads and the interface tile to other circuitry on the first integrated circuit. Similarly, signals from the first integrated circuit are communicated through the interface tile and the micropads to the second integrated circuit. In the event that the first integrated circuit is a programmable logic device having a programmable interconnect structure, the interface tile is part of and hooks into the programmable interconnect structure and provides a general purpose mechanism for coupling signals from the second integrated circuit to the programmable interconnect structure and/or for coupling signals from the programmable interconnect structure to the second integrated circuit.

Abstract: A supporting structure is wafer-bonded to the upper face side of a partially or fully processed device wafer. The device wafer includes a transistor having a well region that extends into the substrate material of the device wafer. The source and drain regions of the transistor extend into the well region. After attachment of the supporting structure, the device wafer is thinned from the back side until the bottom of the well region is reached. To reduce source and drain junction capacitances, etching can continue until the source and drain regions are reached. In one embodiment, all of the well-to-substrate junction is removed in a subsequent etching step, thereby reducing or eliminating the well-to-substrate junction capacitance of the resulting transistor. Resistance between the well electrode and the transistor channel is reduced because the well contact is disposed on the back side of the device wafer directly under the transistor gate.

Abstract: A series capacitor coupling (SCC) structure is controllable to capacitively couple a data input lead of the SCC structure to an output lead of the SCC, or to de-couple the data input lead from the data output lead. An SCC is controlled by a control bit stored in an associated memory cell. A multiplexer is fashioned out of a plurality of such SCC structures such that the edges of a digital signal received on a selected one of a plurality of multiplexer data input leads is coupled through the SCC structures onto an intervening node. The edges of the digital signal on the intervening node are then latched to recreate the incoming digital signal and the latched signal is output onto a multiplexer data output lead. The multiplexer is very fast and has a low leakage current in comparison to conventional transmission gate multiplexers used in programmable logic devices.

Abstract: A balanced clock tree has a coaxial structure when a piece of the tree is viewed in cross-section. A plate is capacitively coupled to the inner conductor that runs down the center of the coaxial structure. This plate is usable to AC couple into the clock signal being propagated down the clock line. A programmable structure is disclosed for doing this whereby the clock signal is capacitively coupled from the clock line onto the input lead of a latch. The latch recreates the clock signal. The latch drives the recreated clock signal onto a local clock conductor. The structure is programmable in that it either couples the clock signal onto the local conductor or not depending on the state of a configuration bit in a memory cell of the programmable structure. In one embodiment, the clock tree can be tapped without substantially affecting signal propagation characteristics of the clock tree.

Abstract: Structures that provide decoupling capacitance to packaged IC devices with reduced capacitor and via parasitic inductance. A capacitive interposer structure is physically interposed between the packaged IC and the PCB, thus eliminating the leads and vias that traverse the PCB in known structures. A capacitive interposer is mounted to a PCB and the packaged IC is mounted on the interposer. The interposer has an array of lands on an upper surface, to which the packaged IC is coupled, and an array of terminals on a lower surface, which are coupled to the PCB. Electrically conductive vias interconnect each land with an associated terminal on the opposite surface of the interposer. Within the interposer, layers of a conductive material alternate with layers of a dielectric material, thus forming parallel plate capacitors between adjacent dielectric layers. Each conductive layer is either electrically coupled to, or is electrically isolated from, each via.

Abstract: An FPGA is readily connectable to a high-speed fiber optic link by snap fitting an external fiber optic cable into an accommodating duplex fiber optic connector of a low-profile packaged FPGA integrated circuit. The low-profile packaged FPGA integrated circuit includes a die-bonded assembly disposed within a co-fired multilayer ceramic integrated circuit package. The die-bonded assembly includes the optoelectronic die, the bottom surface of which is die-bonded and electrically interconnected by micropads to the upper surface of the core of an FPGA integrated circuit die. A first optical fiber communicates light from the connector, through the package, and to a photodetector on the optoelectronic die. A second optical fiber communicates light from a laser diode on the optoelectronic die, through the package, and to the connector. In some embodiments, a micromirror device is disposed within the package to redirect light between the optoelectronic die and the optical fibers.

Abstract: A wafer of integrated circuits under test (ICUT) is tested by supplying power to the ICUTs using power and ground traces that extend between rows of the ICUTs in scribe streets. Test information is supplied to each ICUT by transmitting the test information optically onto the entire wafer. A diode on each ICUT receives the optical test information. The ICUT uses the test information to perform a self-test. Each ICUT has a diode for transmitting optical test information. All ICUTs on the wafer transmit results of the self-tests at the same time. A test device receives the optical test information and identifies the information from each of the many ICUTs, one from another. An entire wafer of ICUTs is therefore tested simultaneously without using a probe card either to power an ICUT or to supply test information to or receive test information from an ICUT.

Abstract: Structures that provide decoupling capacitance to packaged IC devices with reduced capacitor and via parasitic inductance. A capacitive interposer structure is physically interposed between the packaged IC and the PCB, thus eliminating the leads and vias that traverse the PCB in known structures. A capacitive interposer is mounted to a PCB and the packaged IC is mounted on the interposer. The interposer has an array of lands on an upper surface, to which the packaged IC is coupled, and an array of terminals on a lower surface, which are coupled to the PCB. Electrically conductive vias interconnect each land with an associated terminal on the opposite surface of the interposer. Within the interposer, layers of a conductive material alternate with layers of a dielectric material, thus forming parallel plate capacitors between adjacent dielectric layers. Each conductive layer is either electrically coupled to, or is electrically isolated from, each via.

Abstract: A tunable clock distribution system is used to minimize the power dissipation of a clock distribution network in an integrated circuit. The tunable clock distribution system provides a tunable inductance on the clock distribution network to adjust a resonant frequency in the tunable clock distribution system. The inductance is tuned so that the resonant frequency of the tunable clock distribution system approaches the frequency of the clock signal on the clock distribution network. As the resonant frequency of the tunable clock distribution system approaches the frequency of the clock signal, the power dissipation of the clock distribution network decreases. Some embodiments also provide a tunable capacitance on the clock distribution network to adjust the resonant frequency of the tunable clock distribution system.

Abstract: A capacitive interposer (caposer) is disposed inside an integrated circuit package between a die and an inside surface of the package. Conductive layers within the caposer constitute a bypass capacitor. In a through-hole caposer, micro-bumps on the die pass through through-holes in the caposer and contact corresponding landing pads on the package. As they pass through the caposer, power and ground micro-bumps make contact with the plates of the bypass capacitor. In a via caposer, power and ground micro-bumps on the die are coupled to power and ground landing pads on the package as well as to the plates of the bypass capacitor by power and ground vias that extend through the caposer.