Abstract: A pull-up circuit comprises an operational amplifier which forms part of a feedback circuit, acting to bring a pull-up circuit output equal to a reference voltage input. The pull-up circuit may form part of a USB transceiver for incorporation in a USB Device. When the supply voltage of the USB Device is sufficiently high, it is used to provide the required pull-up voltage, with the feedback circuit including the operational amplifier the USB Device is not high enough to provide the required pull-up voltage. In that case, the USB bus voltage is used to generate the reference voltage which is used as an input to the feedback circuit.

Abstract: This invention provides an interface circuit for detecting that a DQS signal from a DDR SDRAM is at an intermediate potential. An interface circuit is connected to at least a signal line which transmits the DQS signal from the DDR SDRAM and reaches an intermediate potential VM when the signal attains an inactive state. The interface circuit has a comparing portion for comparing the potential of the DQS with a threshold potential VREFH which is a potential that is different from the intermediate potential VM.

Abstract: A voltage driver circuit comprises a first transistor having a control terminal and first and second terminals. A second transistor has a control terminal and first and second terminals and generates a drive voltage at the second terminal thereof. First and second current sources bias the control terminals of the first and second transistors with first and second variable current signals, respectively. A capacitance couples the second terminal of the first transistor with the control terminal of the second transistor.

Abstract: A bi-directional buffer is connected between a first node and a second node, wherein the first node is connected by a first pull-up resistor to a first voltage supply rail, and the second node is connected by a second pull-up resistor to a second voltage supply rail. In an embodiment, the bi-directional buffer is enabled when a voltage of the first node does not exceed a first threshold voltage, and/or a voltage of the second node does not exceed a second threshold voltage. However, when the voltage of the first node exceeds the first threshold voltage, and the voltage of the second node exceeds the second threshold voltage, the bi-directional buffer is disabled, which disconnects the first and second nodes. This allows the first node to be pulled up to the first voltage supply rail, and the second node to be pulled up to the second voltage supply rail.

Abstract: An energy-saving circuit and method using charge equalization across complementary nodes reduces power consumption in memory circuits and other circuits such as wide multiplexers having complementary high-capacitance nodes. A change detection circuit detects a state change to be applied to the bitlines, and generates a pulse if a state change is to be applied. A pass gate connected between the nodes is activated in response to the pulse to equalize the charge on the bitlines. The driver circuit enable inputs are also delayed, so that the bitlines are not driven until after the charge has been equalized and the pass gate disabled. In one embodiment, the driver circuits are only enabled momentarily by a pulsed output of the change detector and keeper circuits are employed to retain the bitlines in their asserted states.

Abstract: An address transition detector circuit includes an input node, an output node, a bandgap reference node, and Pbias and Nbias nodes having voltages derived from the bandgap reference node. First through fifth cascaded inverters are each powered by a p-channel and n-channel MOS bias transistors having their gates coupled respectively to the Pbias node and the Nbias node. The input of the first inverter is coupled to the input node. First and second capacitors are coupled respectively to ground from the outputs of the first and fourth cascaded inverters. A NAND gate has a first input coupled to the input node, a second input coupled the output of the fifth cascaded inverter, and an output coupled to the output node.

Abstract: To provide a transmission circuit which can adequately perform a fast data transmission even to a receiving circuit of a host controller or a device controller with a low sensitivity. A transmission circuit transmitting a signal through first and second signal lines that form a differential pair and includes a first terminating resistor terminating the first signal line, a second terminating resistor terminating the second signal line and a terminating resistance control circuit generating a control signal for controlling terminating resistance values of the first terminating resistor and the second terminating resistor. A first resistor takes a first resistance value if a first control signal is active, a nth resistor takes a nth resistance value if a nth control signal is active, the first-nth resistors are coupled, one end of the coupled first-nth resistors is coupled to a reference potential and the other end is coupled to the first signal line or the second signal line.

Abstract: An integrated circuit includes a current mirror circuit for providing a current at an output end, a power-down switch coupled to the output end of the current mirror circuit for controlling access of the current generated by the current mirror circuit based on signals received at a control end of the power-down switch, and a compensating unit coupled to a bias end of the current mirror circuit and the power-down switch for stabilizing voltages at the bias end of the current mirror circuit.

Abstract: A method and circuit of a biased input buffer is described to maximize the quality in the output signals. The input buffer includes a first stage for receiving differential input signals and generating differential internal signals as biased in response to an averaging of the differential internal signals. The input buffer further includes a second stage coupled to the differential internal signals and configured to generate differential output signals. A memory device includes a memory array with the respective input buffer. Differential input signals are received and differential internal signals are generated as biased in response to an averaging of the differential internal signals. Differential output signals are generated in a second stage from the differential internal signals.

Abstract: A wireline transmission circuit includes a first circuit that produces a first variable current, a second circuit that produces a first static current, a trans-impedance amplifier that outputs a first analog signal at a first output node in response to the first variable current and the first static current received at a first input node, and a first feedback resistor connected to the first input node and the first output node.

Abstract: A transmission system, circuit and method are provided herein for converting differential signals into low duty cycle distortion, single-ended signals that are insensitive to variations in PVT and input common mode voltage. In one embodiment, the signal translation circuit includes an input stage for receiving a pair of differential input signals and producing one or more differential output signals; an intermediate stage for combining the one or more differential output signals into a pair of complementary signals from which a common mode voltage is detected; and an output stage for generating a single-ended output signal that switches from a first value to an opposite value when one of the complementary signals is substantially equal to the common mode voltage.

Abstract: The terminating impedance of a networked device in a wired communication channel is controlled to avoid an impedance discontinuity when power is applied and removed from the node or other event occurs that would change the impedance of the signal interface. When the node transmits or receives signals using the communication channel, the transmit or receive device presents a matched termination to the channel. When power is removed or the device is reset, the transmit and receive circuitry is not operational and the matched impedance is therefore maintained by a separate device. The impedance may be varied slowly from a match to a high impedance to allow other devices in the network to adapt to the change in multipath environment that results from the impedance change. Alternatively, the signal interface can be switched to a passive static impedance that is maintained while power is off or the disrupting event occurs.

Abstract: A differential transmission line driver with supplemental current sources that overcome switching anomalies and EMU issues when the logic state of the driver is switching. During a logic transition, a current source, that is directed to the output of the driver, may be prevented from delivering its current. The present invention provides a supplemental current that is active during this transition period to supply the missing current. The present disclosure also details a common mode circuit that maintains a stable common mode output level to help control EMI issues when the power supply for the driver changes.

Abstract: A high speed data communication system uses a single-ended bus architecture with a reference signal extracted from a differential periodic signal that is transmitted along with single-ended data. By using a periodic signal such a clock signal with approximately 50% duty cycle, a much more stable and accurate reference signal is established for receiving single-ended data.

Abstract: An electronic circuit for providing a logic gate function includes a differential signal input, a combining stage, a discriminating stage and a differential signal output. The discriminating stage includes four transistors each having first electrodes and second electrodes and a respective gate electrode. The first electrodes of the four transistors are connected to a common node. The combining stage is arranged to convert differential input signals into gate signals applied to the gate electrodes of some of the four transistors respectively.

Abstract: An input network is provided within an integrated circuit for interfacing with signals produced by an external CML driver apparatus. The input network includes an input for receiving the signals, and this input is coupled to a terminating impedance, a DC attenuator and an AC attenuator. A common-mode correction loop is coupled to the AC attenuator and the DC attenuator for rejecting common-mode noise generated by the CML driver apparatus. The common-mode correction loop can also provide a common-mode voltage suitable for facilitating high-speed operation of low-voltage devices in the internal data path of the integrated circuit. An amplifier can be provided to compensate for signal attenuation in the input network.

Abstract: A bus communication system contains a pair of communication conductors and a driver. The driver contains a plurality of pairs of controlled current source circuit, each pair comprising current source circuits of a first and second, mutually opposite polarity, and a control circuit for matching currents drawn by the current sources in each pair. The current source circuit of the first polarity have outputs coupled to a first one of the communication conductors, the current source circuits of the second polarity have outputs coupled to a second one of the communication conductors. A delay line is provided, with taps coupled to control inputs of the current sources of the first and second polarity, so that the pairs are switched on successively with mutual delays between successive pairs, as determined by the delay line.

Abstract: To provide a transmission circuit which can adequately perform a fast data transmission even to a receiving circuit of a host controller or a device controller with a low sensitivity. A transmission circuit transmitting a signal through first and second signal lines that form a differential pair and includes a first terminating resistor terminating the first signal line, a second terminating resistor terminating the second signal line and a terminating resistance control circuit generating a control signal for controlling terminating resistance values of the first terminating resistor and the second terminating resistor. A first resistor takes a first resistance value if a first control signal is active, a nth resistor takes a nth resistance value if a nth control signal is active, the first-nth resistors are coupled, one end of the coupled first-nth resistors is coupled to a reference potential and the other end is coupled to the first signal line or the second signal line.

Abstract: An output driving circuit has a first and second differential output nodes connected to a first and second external output terminals, respectively. A capacitance connection circuit is connected between the first and second differential output nodes. The capacitance connection circuit connects a capacitance between the first and second differential output nodes. The capacitance connection circuit then adjusts the value of the capacitance in accordance with a control signal.

Abstract: An electronic data processing circuit uses current mode signalling on a communication conductor, wherein a receiver supplies current to the communication conductor to try and keep a voltage on the conductor constant and measures the current that is needed to do so. A transition coding circuit is coupled between a data source circuit and the communication conductor, for driving the communication conductor in a first state in pulses in response to transitions in the logic signal and in a second state outside the pulses. The level that is used for indicating no change is selected so the current that needs to be supplied by the receiver is smaller when no change is signalled than when a change is signalled. Preferably only a nearly zero quiescent current is needed when there is no change.

Abstract: A low voltage positive emitter coupled logic (LV-PECL) buffer fabricated in the complimentary oxide metal silicon (CMOS) process. The LV-PECL buffer in CMOS is operable for a wide frequency range from DC to frequencies as high as 800 MHZ in 0.5 um process. Synchronized feedforward logic is utilized without the need for a feedback loop. N-MOSFET's, which are faster than P-MOSFET's, are used for the implementation of switched current sources. The switched current sources deliver a pull-up current variable in time and as a result have more than two values. The pull-up current is sharply increased in value during the output waveform transition times in an impulse manner.

Abstract: Since voltages of two input terminals of an output unit having an online download function are decided by voltages which are not correlative to each other, a value of an incoming current on the start-up becomes large. The present invention solves the problem of turning-on of a parasitic transistor due to a transitional minus potential even when the voltage of the output unit on a stationary state is set to 0 V in order to reduce the incoming current. In this invention, a switch is turned on and off by a download switching digital signal, and an input from a delay circuit for charging and discharging a condenser in the delay circuit whose one end is connected to a reference potential is input to one of the input terminals of the output terminal while the reference potential is applied to the other input terminal of the output unit. Thus, an input error in the output unit is reduced to prevent an excessive incoming current.

Abstract: A data input buffer for use in a semiconductor device, including: a detection unit for receiving a reference voltage signal and an input data signal through a first input terminal and a second input terminal respectively in order to detect a voltage level of the input data signal based on a result of comparing the input data signal with the reference voltage in response to a clock enable signal inputted through a third input terminal; and a noise elimination unit connected between the first input terminal and the third input terminal for eliminating a noise of the reference voltage signal.

Abstract: In one embodiment, a decision feedback equalizer helps mitigate intersymbol interference in a bi-directional signaling environment. In the particular embodiment, the decision feedback equalizer includes a voltage-to-current converter to source a received differential current to first and second node, a latch to provide logic signal when comparing currents sourced to the first and second nodes, a memory unit to store the logic signals, and a mapping circuit to source first and second feedback currents to the first and second nodes. This embodiment further includes a transmitter to transmit data over a transmission line during receiving, and a digital-to-analog converter to provide a differential current to the first and second nodes to substantially cancel that part of the received differential currents contributed by the transmitter.

Abstract: A method and apparatus for a low jitter predriver for differential output drivers. In one embodiment, the predriver comprises a pull-up circuit having at least one pull-up device of a first device type and a pull-down circuit having at least one pull-down device of the first device type In one embodiment, the pull-up circuit and the pull-down circuit to charge an output node and a complement output node in opposite directions to generate a differential predriver signal pair. Accordingly, using the pull-up and pull-down circuits, the predriver circuit generates differential output signals. In one embodiment, the pull-up device and the pull-down device comprise N-channel metal oxide semiconductor (NMOS) devices. Other embodiments are described and claimed.

Abstract: A high speed data communication system uses a single-ended bus architecture with a reference signal extracted from a differential periodic signal that is transmitted along with single-ended data. By using a periodic signal such a clock signal with approximately 50% duty cycle, a much more stable and accurate reference signal is established for receiving single-ended data.

Abstract: A receiver circuit (12) includes a first gate (24) that receives an input signal (VIN0, VIN1) and has an output (32, 34) for providing an output signal (VG0, VG1). A shifting circuit (20) is coupled for shifting the common mode potential of the input signal to produce a shifted signal (VSH0, VSH1). A second gate (22) has an input (27, 28) that receives the shifted signal and an output coupled to the output of the first gate.

Abstract: A chip to chip interface comprises a driver configured to provide a first signal in response to a change in first data at one edge of a clock signal and a second signal in response to a change in second data at another edge of the clock signal. The chip to chip interface comprises a receiver configured to receive the first signal and the second signal and toggle a first bit in response to the first signal and toggle a second bit in response to the second signal.

Abstract: A multi-threshold complementary metal-oxide semiconductor (MTCMO) bus circuit reduces bus power consumption via a reduced circuit leakage standby and pulsed control of standby mode so that the advantages of MTCMOS repeater design are realized in dynamic operation. A pulse generator pulses the high-threshold voltage power supply rail standby switching devices in response to changes detected at the bus circuit inputs. The delay penalty associated with leaving the standby mode is overcome by reducing cross-talk induced delay via a cross-talk noise minimization encoding and decoding scheme. A subgroup of bus wires is encoded and decoded, simplifying the encoding, decoding and change detection logic and results in the bus subgroup being taken out of standby mode only when changes occur in one or more of the subgroup inputs, further reducing the power consumption of the overall bus circuit.

Abstract: Described is a system for trimming the value of an electronic component. The system comprises: at least one trimming component, each trimming component having an associated switch for selectively connecting that trimming component to the electronic component in response to a corresponding bit in a control vector. A comparator is included for generating an output bit having a first value if a net value of the electronic component and any connected trimming components differs from a desired value. A controller connected to the switches and the comparator generates the control vector in dependence on the output of comparator, the controller comprising a shift register for sequentially receiving successive output bits from the comparator; wherein the control vector comprises the contents of the shift register and wherein a bit of said first value in control vector effects switching of the corresponding switch.

Abstract: When a potential of a power supply line varies according to a flowing current, the gate-source voltage Vgs of a transistor also varies, leading to variations in the constant current between each source follower. In order to solve this problem, a potential Vb of the gate terminal of a transistor as a constant current source is changed in the same manner as a power supply line Vss which is connected to the source terminal of the transistor. Therefore, variations in the constant current are suppressed and variations in the output of the source followers are thus suppressed. In addition, by connecting the circuit having source followers to the output side of a signal line driver circuit, it can be prevented that luminance unevenness of a striped pattern is recognized in a display portion of a semiconductor device.

Abstract: A bus interface is described, in particular in motor vehicles, for connecting a bus device to a bus using a pair of complementary bus lines, including a first driver circuit whose input is connected to the bus device and whose output is connected to the first bus line of the pair of complementary bus lines, and a second driver circuit, which is complementary to the first driver circuit and whose output is connected to the second bus line of the pair of complementary bus lines, the input of the second driver circuit being connected to the output of the first driver circuit.

Abstract: The invention relates to a semiconductor memory device and, more particularly, to an interface system for a semiconductor memory device. The interface includes a transmitter capable of encoding first and second input signals as a plural-bit symbol signal responsive to first and second clocks, respectively, the first clock being out of phase from the second clock. And the interface includes a receiver capable of generating first and second output signals by decoding the symbol signal responsive to third and fourth clocks, respectively. Other embodiments are illustrated and described.

Abstract: A low voltage different signaling (LVDS) includes an LVDS transmitter and an LVDS receiver. The LVDS transmitter includes a feedback compensation circuit, which adjusts and stabilizes the analog image signal to be transmitted to the LVDS receiver according to the voltage difference of the analog image signal and a base signal. The feedback compensation circuit includes a voltage-to-current converting circuit and a pair of current mirror circuits.

Abstract: In the process of transferring a clock signal and a plurality of data signals which are in synchronization with the clock signal, a driving pulse width of a driver switch is feedback-controlled by a clock transmission system (12), whereby the clock signal is transmitted at a small amplitude. A control signal having the pulse width is used for controlling the driver switch in each data transmission system (13), whereby transfer of each data signal at a small amplitude is realized at the same time. Further, in a clock reception system (10), the control signal having the pulse width is used in delay control of a clock delay circuit, whereby an optimum latch timing of received data in each data reception system (11) is realized.

Abstract: A high speed low power data transfer bus circuit that reduces bus power consumption by imposing a limited, controlled voltage swing on the associated data bus. In one embodiment, an inverter is coupled with a pMOS pass transistor and an nMOS discharge transistor, and the combination is coupled with a data bus. The discharge transistor and pass transistor can be programmed to provide a preselected bus operational characteristics. In another embodiment, multiple nMOS discharge transistors can be coupled to the data bus via the pass transistor, with each of the discharge transistors being selectively programmed to provide additional preselected bus operational characteristics, multiple, programmable discharge transistors, thus selectably imposing encoded and multilevel logic signals on the data bus. In another embodiment, a bidirectional data transfer bus circuit couples two data busses while imposing a limited, controlled voltage swing during the transfer.

Abstract: A method is described for transmitting signals on a pair of lines, whereby the signals pass alternately from a low level to a high level. The signals on one line of the pair transmit a complementary level of signals to the other line of the pair, whereby signal drivers are used in a manner to affect an exchange in the levels of the transmitted signals. First, the signal drivers that send complementary levels of signals to the two lines are isolated from the lines. Second, the lines are short-circuited so that an identical intermediary potential between the low-level and the high-level signal, is applied. Third, the short-circuit is removed and the signal drivers are connected so that inversely complementary levels of signals can be sent to both lines.

Abstract: An electronic circuit includes a selectively configurable differential signal interface and a selection control input for selecting one of a plurality of standard differential signal interfaces for configuration of the differential signal interface. The selection control input selects one of the following plurality of standard differential signal interfaces: reduced swing differential signaling (RSDS), low voltage differential signaling (LVDS), mini low voltage differential signaling (mini-LVDS), and bussed low voltage differential signaling (BLVDS), for configuration of the differential signal interface. The electronic circuit may also include a plurality of selectable voltage sources (611, 612, 613) and a plurality of selectable current sources (614, 615, 616, 617), for selecting, in response to an input signal at the selection control input, at least one of an operating D.C. voltage, a standard differential signal voltage, and a standard differential signal current for the differential signal interface.

Abstract: A method is described that involves driving a first current through a line and a termination resistance so that a logical value on the line changes from a first logical value to a second logical value. The method also includes holding the second logical value on the line by driving a second current through the line and the termination resistance where the second current less than the first current. An apparatus is described that includes a driver that drives a first current through a line and a termination resistance so that a logical value on the line changes from a first logical value to a second logical value. The driver holds the second logical value on the line by driving a second current through the line and the termination resistance. The second current is less than said first current.

Abstract: Data processing circuit including a single rail bus having a single rail line, a dual rail bus having a first dual rail line for data bits and a second dual rail line for inverted data bits, and a converter for converting signals on the single rail bus into signals on the dual rail bus and vice versa. The converter has a read driver for transferring signals on the first dual rail line to the single rail bus when the read driver is active, a write driver for transferring the signals on the single rail bus to the first dual rail line when the write driver is active, a producer for producing the signals on the second dual rail line from the signals on the first dual rail line when the write driver is active, and a controller for controlling the drivers so that at most only one driver is active.

Abstract: A multi-device system and method for controlling voltage peaking of an output signal transmitted between input and output circuits of integrated circuit devices utilizes various electrical elements that can be adjusted after the fabrication of the integrated circuit devices to change the impedance of the input and output circuits. These adjustable electrical elements include one or more pass transistors in the input circuit whose on-resistances can be changed by adjusting a control signal supplied to the pass transistors. The adjustable electrical elements may also include one or more of the following: an adjustable current source, an adjustable resistor and a resistance-adjustable transistor operated as an adjustable resistor.

Abstract: In a driver circuit having a plurality of drivers for driving signals in parallel, the drivers are each connected to an input signal line for receiving a respective input signal and to an output signal line for outputting a respective driven output signal. An output signal line of one of the drivers may be connected, via a switch or switching means, to an output signal line of another of the drivers. A control circuit is connected to one of the drivers and is used to drive the switch or switching means in such a manner that the switching means can be activated, for charge equalization, by the control circuit following a driving operation in one of the drivers. A respective associated memory circuit, by which an associated logic circuit for driving one of the switch or switching means is connected to the relevant output signal line, is connected to the respective output signal line. Overall power consumption of the driver circuit can be minimized.

Abstract: A data transmission system includes a first bus; a first bus master coupled to the first bus; a second bus master coupled to the first bus; a bus arbiter coupled to the first and second bus masters to provide an authorization of bus master operation to the first and second bus masters selectively; and a bus request holding circuit, which is coupled between the second bus master and the bus arbiter. The bus request holding circuit holds a bus request signal supplied from the second bus master for an appropriate period of time in response to a signal from the first bus master.

Abstract: A simultaneous bi-directional signal transmission system includes a first semiconductor device, a second semiconductor device, and one or more transmission lines. The first semiconductor device includes a first output MUX which receives first binary data and converts the first binary data into a first signal having one of at least four levels; a first transmitter which is connected to the first output MUX and outputs the first signal via the transmission line to the second semiconductor device; a first receiver which compares one or more reference voltages selected by the first signal with a third signal input via the transmission line and outputs the comparison result; and a first input encoder which detects the second binary data based on the comparison result output from the first receiver.

Abstract: A termination scheme for the I/O circuitry of a programmable device, such as a field-programmable gate array (FPGA), has programmable resistors switchably connected between reference voltages and two of the device's I/O pads and additional programmable resistors switchably connected between the two I/O pads. By appropriately controlling the reference voltages and the resistance levels, a single implementation of the termination scheme can be used to conform to a relatively wide variety of symmetric and non-symmetric complementary and differential signaling applications.

Abstract: A bidirectional bus driver includes a first buffer which supplies the data signal to the second bus when the first control signal is enabled; a second buffer which supplies the data signal to the first bus when the first control signal is enabled; a first control; a second control; a third buffer which supplies a signal in the second bus to the first bus when the second control signal is enabled; and a fourth buffer which supplies a signal in the first bus to the second bus when the third control signal is enabled. The first control circuit enables the second control signal when a signal transition is detected in the second bus while the first control signal is not enabled; and the second control circuit enables the third control signal when a signal transition is detected in the first bus while the first control signal is not enabled.

Abstract: A preferred embodiment includes a distributed network of a plurality of dynamically configurable bi-directional input/output (I/O) cells, each including a forward datapath having a first receiver, for receiving a first input signal from downstream driver on a first port of a signal line, coupled to a first driver for sending a first output signal to a first upstream receiver on a second port of the signal line; and a reverse datapath having a second receiver, for receiving a second input signal from a second downstream driver on the second port of the signal line, coupled to a second driver for sending a second output signal to a second upstream receiver on the first port of the signal line; wherein the first input signal and the second output signal are transmitted concurrently on the first port of the signal line.

Abstract: A differential data transmitter includes a first pre-driver configured to receive a differential data signal, a delay circuit configured to receive the differential data signal in parallel with the first pre-driver, and output the differential data signal with a delay time, and a second pre-driver configured to receive an output signal from the delay circuit. The delay circuit is capable of changing the delay time in accordance with a control signal. An output driver is configured to receive first and second output signals from the first and second pre-drivers, and output a pre-emphasis waveform signal that corresponds to a subtraction signal between the first and second output signals.

Abstract: An expanding module for serial transmission between a chip and a plurality of interface units is disclosed. The module is comprised of a plurality of first OR gates and a plurality of second OR gates, corresponding respectively to each interface unit, which logically evaluates the control signals and the data signals transmitted by the chip to the interface units, and an AND gate that logically judges the feedback data signals from the interface units to decide which interface unit is to communicate with the chip.

Abstract: A bi-directional input/output (IO) cell for transmitting and receiving data signals simultaneously over a single line. The bidirectional IO cell having an IO node adapted to connect to the line. A driver has an output connected to the line and an input for receiving a core output signal. A first differential amplifier has a first input connected to the IO node and a second input connected to a high voltage reference circuit. A second differential amplifier has a first input connected to the IO node and a second input connected to a low voltage reference circuit.