Abstract: A circuit for glitchless switching between asynchronous clocks includes a select circuit and enable circuits. The select circuit receives a selection signal for selecting one of the clock input signals and to generate enabling signals for activating the corresponding enable circuits on the basis of the current output signal. The feedback logic in the circuit ensures that at any given instance only one of the clock input signals is outputted so as to avoid the formation of glitches. The circuit can be applied to switches between any number of asynchronous clocks.

Abstract: A break-before-make predriver for disabling a PFET of an output driver before enabling an NFET, and vice versa. The predriver includes an input inverter, two cross-coupled inverters, and output buffers. The predriver provides enhanced break-before-make action through sizing the NFETs larger than the PFETs in the predriver's cross-coupled inverters. The input inverter, the cross-coupled inverters and the first and second output buffers are sized with respect to each other such that substantially equal break before make action is provided on both rising and falling edges. The predriver also includes level-shifting capabilities through a different voltage supply at the PFETs of the cross-coupled inverter. The predriver also includes two data output nodes for connection to the two inputs of an output driver. The predriver provides for tristate action by disabling the signal from the predriver output nodes.

Abstract: A level detector has an input circuit adapted to accept signals of multiple signal levels for detecting a specific level. The signal levels include a first signal level and a larger second signal level. Electronic components of the input circuit have reliability levels less than the second signal level. A latch circuit is coupled to the input circuit for latching a signal consistent with a detected level of an accepted signal.

Abstract: A main die and a stacked die are included in the same component package. A transmission gate (370) is implemented on the main die, and can be enabled to receive leakage current in a connection (318) between the main die and the stacked die, and to conduct the leakage current to a bonding pad (344) that is accessible external to the package. Thus, the connectivity between the main die and the stacked die can be tested after the dies are packaged. The transmission gate is disabled during high-speed testing and normal operation. The package can also include a multiplexer (364) that is enabled during high-speed testing to input and output test signals at the package level. A direction signal is used to indicate whether test signals are being input to or output from the main die.

Abstract: A signal interface circuit has a signal path for communicatively coupling host circuitry to peripheral circuitry of multiple peripherals. Communication signals in the signal path are of a peripheral signal level. The signal path has electronic components adapted for use in communicating signals between the host circuitry and the peripheral circuitry. The electronic components in the signal path have reliability limits less than the peripheral signal level. The configuration of the electronic components in the signal path allow communication of signals at the peripheral signal level.

Abstract: A multiple supply voltage device includes an input/output (I/O) network operative at a first supply voltage, a core network coupled to the I/O network and operative at a second supply voltage, and a power-on-control (POC) network coupled to the I/O network and the core network. The POC network is configured to transmit a POC signal to the I/O network and includes an adjustable current power up/down detector configured to detect a power state of the core network. The POC network also includes processing circuitry coupled to the adjustable current power up/down detector and configured to process the power state into the POC signal, and one or more feedback circuits. For reducing the leakage current while also improving the power-up/down detection speed, the feedback circuit(s) are coupled to the adjustable current power up/down detector and configured to provide feedback signals to adjust a current capacity of the adjustable current power up/down detector.

Abstract: Methods and apparatuses are presented for voltage tolerant floating N-well circuits. An apparatus for mitigating leakage currents caused by input voltages is presented which includes a first transistor having a source coupled to a positive voltage supply, and a drain coupled to a floating node. The apparatus may further include a controllable pull-down path coupled to a negative voltage supply and the first transistor, wherein the controllable pull-down path is configured to turn on the first transistor and pull-up the floating node during a first state. The apparatus may further include a second transistor having a source coupled to a gate of the first transistor, and drain coupled to the floating node, wherein the second transistor is configured to place the floating node at a floating potential during a second state.

Abstract: An electrostatic discharge (ESD) protection circuit uses two N-channel field effect transistors (NFETs) to conduct ESD current from a first to a second supply node. During the ESD event, an ESD detection circuit couples the gates of both NFETs to the first supply node through separate conductive paths. In one novel aspect, an RC trigger circuit includes a capacitance that is charged through a resistance. The resistance involves a P-channel transistor whose gate is coupled to the gate of the second NFET. During a normal power-up condition, the P-channel transistor is conductive, thereby preventing the RC trigger from triggering if the supply voltage VDD were to rise rapidly. In another novel aspect, a novel level-shifting inverter drives the second NFET. The level-shifting inverter uses a pull down resistor to avoid snap-back and also isolates the gate of the second NFET from a capacitively loaded third supply node.

Abstract: An electronic device is described. The electronic device includes a first integrated circuit (IC) and a second integrated circuit (IC). The electronic device also includes a multiplexer configured to multiplex a parallel data signal into a serial data signal, and a transmitter configured to transmit the serial data signal from the first IC to the second IC. The electronic device further includes a receiver configured to receive the serial data signal. The receiver includes a clamp circuit configured to clamp the voltage swing of an analog node within a determined range. The clamp also helps to extend the bandwidth of the receiver.

Abstract: A protection system implemented on one die of a multi-die package provides a discharge path for excess voltages incurred on one or more other die of the package. Ground paths are provided for certain circuitry in the package that have high noise-sensitivity, and ground paths are provided for certain circuitry in the package that have low noise-sensitivity relative to the high noise-sensitivity circuitry. The grounds of high noise-sensitivity circuitry of multiple die are shorted together, resulting in a common high noise-sensitivity ground. The grounds of low noise-sensitivity circuitry of multiple die are shorted together, resulting in a common low noise-sensitivity ground. A pre-designated removable path is included on the package external to the die, which shorts the common high noise-sensitivity ground and the common low noise-sensitivity ground. The removable path may be removed during manufacturing, if noise present on the shorted grounds results in unacceptable performance degradation.

Abstract: A signal driver for an interface circuit has a first stage level shifter to accept input signals and output signals at a first signal level. The signal driver also has a second stage level shifter coupled to the first stage level shifter to output signals at a second signal level. Electronic components of the first and second stage level shifter have reliability limits less than the second signal level. The first and second stage configurations of the first stage level shifter and the second stage level shifter prevents exposing the electronic components to terminal to terminal signal levels higher than the reliability limits when processing signals for output at the second signal level.

Abstract: A signal interface circuit has a signal path for communicatively coupling host circuitry to peripheral circuitry of multiple peripherals. Communication signals in the signal path are of a peripheral signal level. The signal path has electronic components adapted for use in communicating signals between the host circuitry and the peripheral circuitry. The electronic components in the signal path have reliability limits less than the peripheral signal level. The configuration of the electronic components in the signal path allow communication of signals at the peripheral signal level.

Abstract: An interface input has an input circuit adapted to receive input signal levels higher than a maximum signal level that a host circuitry's electronic components can reliably handle. The input circuit shifts the level of the input signal to a desired signal level. A keeper circuit is coupled to the input circuit and maintains trigger levels of the shifted signals consistent with the input signal level.

Abstract: A first I/O pad has a first type transistor disposed at a first end of the first I/O pad. A second I/O pad has another first type transistor disposed at a first end of the second I/O pad. The first end of the first I/O pad abuts the first end of the second I/O pad, so the first type transistor is adjacent to the other first type transistor.

Abstract: A level detector has an input circuit adapted to accept signals of multiple signal levels for detecting a specific level. The signal levels include a first signal level and a larger second signal level. Electronic components of the input circuit have reliability levels less than the second signal level. A latch circuit is coupled to the input circuit for latching a signal consistent with a detected level of an accepted signal.

Abstract: A level shifter has at least one of either a pull up or a pull down circuit. The circuit is made of electronic components with reliability limits less than a maximum signal level output by the level shifter. The level shifter also has a timing circuit coupled to at least on of either the pull up or pull down circuit. The timing circuit controls a time of application of an input signal to at least one of either the pull up or pull down circuit preventing a terminal to terminal signal level experienced by the electronic components exceeding the reliability limits.

Abstract: This disclosure describes a clock circuit for a memory controller. The described circuit uses a processor clock signal to generate an input clock signal for use during write operations to the memory, or to generate a feedback clock signal for use during read operations from the memory. The circuit is particularly applicable to mobile wireless devices that include memories that do not generate a strobe. The clock circuit may comprise a driver in series with a resistor element that generates an input clock signal for input to a memory, and a resistor-capacitor (RC) filter in series with a receiver that generates a feedback clock signal for output from the memory, wherein an input to the RC filter is tapped between the driver and the resistor element.

Abstract: A conferencing assembly for use with at least one computer, the assembly including a table top forming a table top opening, a leg support structure, a display screen supported adjacent the top surface, a switcher for controlling input to the display screen, a plurality of handsets, each hand set including a selector button usable to send a signal to the switcher thereby causing the switcher to link a computer associated with the selector button to the display, a plurality of handset cables, each handset cable having first and second ends linked to the switcher and an associated selector button, respectively, for passing signals from the selector buttons to the switcher, a take up assembly including a separate weight for each of the handset cables, the take up assembly disposed below the top member and aligned with the top opening, each handset cable linked to an associated weight, each weight applying a force tending to pull the second end of the associated handset cable into the opening.

Abstract: A digital output driver includes a pre-driver and a driver that may be implemented with thin-oxide FETs. The pre-driver generates first and second digital signals based on a digital input signal. The first digital signal has a first voltage range determined by a first (e.g., pad) supply voltage and an intermediate voltage. The second digital signal has a second voltage range determined by a second (e.g., core) supply voltage and circuit ground. The driver receives the first and second digital signals and provides a digital output signal having a third voltage range determined by the first supply voltage and circuit ground. The pre-driver may include a latch and a latch driver. The latch stores the current logic value for the digital input signal. The latch driver writes the logic value to the latch. The latch driver is enabled for a short time duration to write the logic value and is turned off afterward.

Abstract: Methods and apparatuses are presented for voltage tolerant floating N-well circuits. An apparatus for mitigating leakage currents caused by input voltages is presented which includes a first transistor having a source coupled to a positive voltage supply, and a drain coupled to a floating node. The apparatus may further include a controllable pull-down path coupled to a negative voltage supply and the first transistor, wherein the controllable pull-down path is configured to turn on the first transistor and pull-up the floating node during a first state. The apparatus may further include a second transistor having a source coupled to a gate of the first transistor, and drain coupled to the floating node, wherein the second transistor is configured to place the floating node at a floating potential during a second state.