Abstract: In an integrated circuit having input circuitry whose positive and/or negative input signals are gated by one or more clocked input switches, the switch clock signal CLK_SW used to clock the input switch(es) is automatically generated based on the higher of the IC's power supply voltage VDD and the positive input signal voltage Vplus. In one embodiment, a clock level shifter shifts an input clock signal CLK_VDD from the VDD voltage domain to generate a level-shifted clock signal CLK_VPLUS in the Vplus voltage domain. Based on a control signal VSEL, a clock selector selects either the input clock signal or the level-shifted clock signal to be the switch clock signal. An over-voltage detector generates both the logic state and the voltage domain of the control signal based on the higher of VDD and Vplus, such that the input switches are appropriately clocked even during over-voltage conditions in which Vplus>VDD.

Abstract: A de-mapping circuit for de-mapping input words of a first length into output words of a second length different from the first length. In one embodiment, the circuit includes a word register of the first length and temporary registers of the second length. The word register successively stores each of the inputs words in response to cycles of a clock. The temporary registers temporarily store the output words. Multiplexers configured by address signals select bits from stored input words and store the selected bits into the temporary registers to form temporarily stored output words.

Abstract: In one embodiment, a programmable logic device includes a memory and an input/output (I/O) interface adapted to enter a variable response mode responsive to an assertion of a control signal. The I/O interface is operable in the variable response mode to respond to a read command from an external device by retrieving data from the memory and to shift dummy data to the external device until an internal data ready signal is asserted.

Abstract: In one embodiment, an integrated programmable device has a plurality of current sense amplifiers for reading data from non-volatile memory and a reference generator that provides common bias reference voltages to the sense amplifiers. The sense amplifiers can read data from the non-volatile memory at low power supply voltage levels (e.g., 750 mV) relative to the nominal supply level (e.g., 1.2V). Each sense amplifier has a trans-impedance amplifier that converts a memory bit-line current into a voltage level indicative of whether a selected memory cell is programmed or erased. The trans-impedance amplifier has a current mirror with a high-threshold regeneration device that lowers the sense amplifier's range of operating voltages. Each sense amplifier also has a level-shifted inverter that further lowers the sense amplifier's operating voltage range.

Abstract: In one embodiment, a hybrid output buffer having both an H-bridge mode and a CML mode of operation includes a plurality of transistor switches arranged between an upper rail and a bottom rail. A first pair of the transistor switches couples between the upper rail and respective output nodes. A pair of resistors couples between the output nodes and a central node. During H-bridge mode, the hybrid output buffer controls a potential of the upper rail responsive to a feedback signal proportional to a difference between a potential of the central node and a common-mode voltage.

Abstract: In one embodiment, an integrated circuit includes a pin and a current source for driving current through the pin into an external resistor such as a resistor on a circuit board to generate a pin voltage. The integrated circuit includes an analog-to-digital converter for converting the pin voltage into a digital value, such as an address for the integrated circuit.

Abstract: In one embodiment, an integrated circuit chip has an input/output (I/O) interface and programmable fabric. The I/O interface restricts access to scan testing of the chip by requiring (1) a specific scan-testing instruction, (2) a specific manufacturing key, and (3) a specific fabric pattern value from a specific set of registers in the programmed fabric. In addition or alternatively, the I/O interface has circuitry that enables scan testing of most of the logic of the I/O interface itself, including the logic being driven by the JTAG TAP state register.

Abstract: In one embodiment, a bandgap reference circuit is designed with three trimmable elements to generate a temperature-independent bandgap reference voltage VBG: a VBG adjustment resistance ?R1, a VBG slope adjustment resistance ?R2, and a curvature compensation adjustment voltage VCU. Instances of the bandgap reference circuit can be trimmed in two phases: a characterization phase during which a triple-trim process determines design-specific trim values for the VBG slope adjustment resistance ?R2 and the curvature compensation adjustment voltage VCU and a production phase during which a single-trim process determines instance-specific values for the VBG adjustment resistance ?R1. Since the characterization phase can be applied to a relatively small number of instances of the bandgap reference circuit, the two-phase trimming technique is suitable for efficient mass production and high production yield.

Abstract: In one embodiment, a loss-of-signal detector is provided that is immune to variations in common mode voltage for a received differential input signal. The loss-of-signal detector is configured is to use a reference voltage that depends upon the common mode voltage.

Abstract: In one memory array embodiment, in order to compensate for bit-line leakage currents by OFF-state bit-cell access devices, a leakage-current reference circuit tracks access-device leakage current over different process, voltage, and temperature (PVT) conditions to generate a leakage-current reference voltage that drives a different leakage-current abatement device connected to each different bit-line to inject currents into the bit-lines to compensate for the corresponding leakage currents. In one implementation, the leakage-current reference circuit has a device that mimics the leakage of each access device configured in a current mirror that drives the resulting leakage-current reference voltage to the different leakage-current abatement devices.

Abstract: Various techniques are provided to configure embedded hardware resources of a programmable logic device (PLD). In one example, a method includes receiving configuration information for a plurality of hardware modules of an embedded hardware block of a PLD. The configuration information is received from a user of a computer system external to the PLD. The method also includes generating a plurality of models of the hardware block. The method also includes merging the generated models into a combined model of the hardware block. The combined model includes the configuration information received for the hardware modules of the hardware block. Related systems and additional techniques are also provided.

Abstract: A margin circuit for controlling skew between first and second signals in order to determine margin, includes a variable delay circuit and a margin controller. Based on a current code value, the delay circuit applies a delay to the second signal to generate a delayed second signal. The margin controller generates the current code value for the variable delay circuit to be any one of a plurality of available code values. In one embodiment, the margin circuit is a write margin circuit that generates a first clock signal and a delayed second clock signal used to generate transmit (TX) clock and data signals having a non-zero phase offset between them. In another embodiment, the margin circuit is a read margin circuit that applies a phase offset between receive (RX) clock and data signals to enable the RX clock signal to be used to recover data from the RX data signal.

Abstract: To protect victim bondwires in a packaged electronic component from crosstalk induced by noisy aggressor bondwires, shielding bondwires are configured between the victim bondwires and the aggressor bondwires. The shielding bondwires, on either side of the victim bondwires, are connected to the same reference voltage on the package side of the component and to each other on the die side of the component, e.g., via a metal connection mounted on the die. As configured in one embodiment, the shielding bondwires and metal connection form a two-dimensional Faraday cage that shields the victim bondwires from crosstalk induced by the aggressor bondwires.

Abstract: In one embodiment, an integrated programmable device has a plurality of current sense amplifiers for reading data from non-volatile memory and a reference generator that provides common bias reference voltages to the sense amplifiers. The sense amplifiers can read data from the non-volatile memory at low power supply voltage levels (e.g., 750 mV) relative to the nominal supply level (e.g., 1.2V). Each sense amplifier has a trans-impedance amplifier that converts a memory bit-line current into a voltage level indicative of whether a selected memory cell is programmed or erased. The trans-impedance amplifier has a current mirror with a high-threshold regeneration device that lowers the sense amplifier's range of operating voltages. Each sense amplifier also has a level-shifted inverter that further lowers the sense amplifier's operating voltage range.

Abstract: In one embodiment, multiple (serializer-deserializer) SERDES channels are aligned by selectively slipping one or more of the incoming serial data streams one bit at a time prior to deserialization. Within each SERDES channel, a slip circuit slips the corresponding serial data stream by one bit (i.e., one unit interval (UI)) by extending the high portion of the duty cycle of a corresponding clock signal. The high portion of the clock signal is extended using a 3-to-1 mux that selects a fixed high signal, such as the high power supply rail, as an intermediate mux output signal whenever transitioning between two different applied clock signals that are offset from one another by one UI. In this way, the slip circuit avoids glitches that might otherwise result from switching directly between the two clock signals.

Abstract: In one embodiment, a core logic section of an integrated circuit is switched to be powered by a standby mode power voltage lower than a normal mode power voltage when the circuit is switched into a standby mode. The standby mode power voltage, however, is too low relative to normal ground to drive a transition logic section of the circuit. A special ground bus is provided in the transition logic section. The special ground bus is pulled down to a voltage below normal ground (i.e., a negative voltage) when the circuit is switched to the standby mode.

Abstract: A ball-grid-array (BGA) package is disclosed that includes traces within a BGA substrate. At least one of the traces is configured to match a low-impedance load presented by a BGA substrate pad and associated circuitry on a flip-chip die to an impedance of a circuit board trace. Each configured trace includes a relatively narrow section coupling to a tapered section that widens from the relatively narrow section to join a relatively wider trace section.

Abstract: In one embodiment, a phase locked loop (PLL) circuit in a device includes selectable feedback paths and a multiplexer. An internal feedback path is adapted to pass a first input clock signal to the PLL circuit during a low power operation mode of the device and an external feedback path is adapted to pass a second input clock signal to the PLL circuit during a normal operation mode of the device. The multiplexer is provided for selecting between the internal and external feedback paths.

Abstract: In one embodiment, an integrated circuit design tool is provided that includes a main window graphical user interface (GUI) and several tool GUIs. Cross probing of features from a source tool GUI to a target tool GUI occurs by the source tool GUI transmitting a probe request to the main window GUI; wherein the probe request identifies one or more cross-probed features for the target tool GUI. In response, the main window GUI commands a plug-in installation of the target tool GUI if the target tool GUI has not yet been instantiated. The main window GUI transmits a notification of the probe request to the target tool GUI. In response, the target tool GUI displays the cross-probed features.

Abstract: In one embodiment, a voltage discharge (VD) system has a slow VD subsystem that provides two concurrent discharge current paths to at least begin to discharge both positive and negative voltages: a first path from the positive-voltage node to ground and a second path from the positive-voltage node to the negative-voltage node. In addition to this relatively slow VD subsystem, the VD system can also have a conventional fast VD subsystem that is turned on after the slow VD subsystem has reduced the positive and negative voltages to some degree (e.g., half of each charge removed). Such a VD system can eliminate dangerous overshoot conditions, even when control-signal skew is present.