Abstract: An elastic interface apparatus and method are implemented. The elastic interface includes a plurality of storage units for storing for storing a stream of data values, wherein each storage unit sequentially stores members of respective sets of data values. Each data value is stored for a predetermined number of periods of a local clock. Selection circuitry may be coupled to the storage units to select the respective data value from the data stream for storage in the corresponding storage unit. Data is sequentially output from each storage unit in synchrony with the local clock on a target cycle of the local clock.

Abstract: A method and apparatus are disclosed for initiating a start-up operation of a system (1′) having a master device (1) and a slave device (14a-14n). The method comprises steps of: A) exercising the slave device (14a-14n) using the master device (1) to determine a temporal range within which temporal relationships of electrical signals need to be set in order to operate the system (1′) without error; B) setting the temporal relationships of the electrical signals so as to be within the determined temporal range; and C) storing a record of the determined temporal range, for subsequent use in operating the system (1′). In one embodiment of the invention, the system (1′) includes a memory control system of a computer system (1″), and the slave device (14a-14n) includes memory devices of the computer system (1″).

Abstract: A first circuit and a second circuit are connected by a pumped signal line that conducts a signal having a plurality of states. A dynamic termination circuit is connected to the pumped signal line. The dynamic termination circuit includes a switch responsive to the signal conducted by the pumped signal line such that the dynamic termination circuit is enabled only in response to certain of the plurality of states of the signal. In one embodiment, the switch is a first transistor that is coupled in series with a first impedance between a first reference voltage and an intermediate node. In this embodiment, the dynamic termination circuit further includes a second transistor coupled in series with a second impedance between a second reference voltage and the intermediate node and only first and second inverters that are each coupled between the intermediate node and the control input of a respective one of the first transistor and the second transistor.

Abstract: A clock signal distribution system is disclosed for providing synchronous clock signals to a plurality of electronic circuit devices. The system includes a clock signal generator means for providing a single frequency sinusoidal clock signal output and a plurality of electronic circuit devices. A clock signal distribution network including interconnected resonant segments of a transmission line 13 connected to the clock signal of the clock signal generator and to the plurality of electronic circuit devices for providing separate synchronous, phase aligned clock signals to the electronic circuit devices. The transmission line segments have lengths matched to the clock signal frequency wavelengths to eliminate clock signal distribution problems such as skew, jitter and pulse distortions.

Abstract: A driver circuit has an output node coupled to a chip pad. A first PFET and a first resistor are connected between a power supply and the output node, wherein the first resistor is connected between the first PFET and the output node. A first NFET and a second resistor are connected between a ground potential and the output node, wherein the second resistor is connected between the first NFET and the output node. A third resistor is connected between an input to the driver circuit and a gate electrode of the first PFET. A fourth resistor is connected between the input to the driver circuit and a gate electrode of the first NFET. The pre-drive circuitry for driving the input to the PFET may include an NFET coupled between the ground potential and the input, wherein the gate electrode of the NFET receives the data signal to be driven.

Abstract: A system and method for providing a high speed differential receiver circuit is disclosed. The system comprises a source device. A receiver is coupled to the source device. The receiver receives first and second differential signals at a first input and a second input and provides first and second output signals at a first output and a second output. The system also comprises a first plurality of load devices coupled to the first output. The first plurality of load devices control a first voltage swing at the first output. The system also comprises a second plurality of load devices coupled to the second output. The second plurality of load devices control a second voltage swing at the second output.

Abstract: An electronic apparatus is disclosed having: a plurality of electronic devices with the same or different internal voltages; an interconnection between two or more of the plurality of electronic devices; each of said two or more electronic devices has an internal voltage; driver and receiver circuits which send and receive signals at a selectable communication voltage levels for interfacing between said two or more electronic devices, at a common communication voltage which is less than the highest value of said internal voltages of said two or more electronic devices; a circuit for configuring the driver and receiver circuits; and the driver circuit are configured to have a substantially constant output impedance independent of their output voltage.

Abstract: Among a plurality of signals, each phase-shifted with respect to the others, one signal is repeatedly substituted for another as a clock signal, to reduce a phase error of the clock signal with respect to a reference clock. The substitutions are timed to occur during intervals tending to reduce disturbances to the clock signal. Also, such substitution of a signal is responsive to occurrence of at least one cycle of the signal subsequent to the clock being supplied by an immediate predecessor of the signal, which tends to prevent erroneous substitutions of one signal for another.

Abstract: A method and apparatus are provided for generating synchronized clock signals. According to the method and apparatus, first and second pluralities of signals are generated, having time-varying phase differences with respect to a reference clock. The first clock is supplied by a succession of signals from among the first plurality of signals, in which one of the signals succeeds another responsive to a first phase difference. The second clock is supplied by a second succession of signals from among the second plurality of signals. One signal in the second succession of signals succeeds another responsive to a second phase difference. The succession among the first plurality of signals is also responsive to the second phase difference.

Abstract: A CMOS differential amplifier uses a first pair of complementary MOSFETs and a second pair of complementary MOSFETs coupled to a power supply (by another pair of MOSFETs) in such a manner as to be self-biasing and have improved channel-length modulation characteristics. An N-type MOSFET couples the first and second complementary MOSFET pairs to ground potential via a first resistor, and a P-type MOSFET couples the first and second complementary MOSFET pairs to a power-supply via a second resistor. The first and second resistors can be provided using non-salicided N-type MOSFET resistors. The third N-type MOSFET preferably has a low-threshold voltage, including a zero-threshold voltage, and the substrates of the P-type MOSFETs in the first and second complementary pairs are further preferably connected to the sources of those MOSFETs in order to reduce body-sensitivity effects.

Abstract: A clock generation apparatus and method for generating clock signals for a microprocessor integrated circuit. The clock generation apparatus includes a device which generates a reference frequency, an acoustic wave oscillator having an oscillation frequency slightly faster than the reference frequency and a circuit configuration coupled to the acoustic wave oscillator which generates frequency bearing signals in response to an output of the acoustic wave oscillator. The frequency bearing signals carry negligible jitter. The circuit configuration includes a quadrature rotator for controlling clock phase, a clock distributor for efficiently dispersing clock signals to the microprocessor integrated circuit, a bus divider which provides a feedback clock signal phase aligned with the reference frequency, a phase detector for detecting the phase difference of a bus clock signal and the feedback clock signal, and a digital filter responsive to the phase detector.

Abstract: A CMOS differential to single-ended converter is implemented. A differential input stage comprised of a pair of N-channel transistors draws current through two fixed current P-channel load transistors. A first N-channel differential transistor provides negative feedback bias control of a current source transistor coupled to the differential input stage. The negative feedback control provides increased current gain in the second N-channel transistor, which drives a CMOS inverter to a full rail-to-rail voltage swing on its output.

Abstract: A voltage controlled-oscillator ring oscillator having an adjustable high-frequency reference and an adjustable low-frequency reference. A mixer and a plurality of delay elements comprise a delay interpolating oscillator ring. The mixer receives a high-frequency reference input signal from a first multiplexer which selects the output of one of several delay elements having relatively short delay loop paths. The mixer receives a low-frequency reference input signal from a second multiplexer which selects the output of one of several delay elements having relatively long delay loop paths. The frequency of the mixer output is continually adjustable between the high-frequency reference and the low-frequency reference. As operating conditions change the first and second multiplexers can select the outputs of different delay elements in order to change the frequency of the high-frequency and low-frequency references.

Abstract: A CMOS current reference is provided that is relatively independent of supply voltage and generates a substantially steady current. The current reference includes a plurality of P-channel FETs and a plurality of zero threshold voltage N-channel FETs that provide a high level of voltage supply rejection at relatively low supply voltage levels (1.5 to 3.3 volts). Utilization of the P-channel FETs and the zero threshold voltage N-channel FETs in a current mirror and cascade configuration reduces the sensitivity of the current to variations in the supply voltage. The current reference exhibits higher offset voltage capabilities. In addition, the CMOS current reference may be designed to compensate for process variations since the current will increase as the channel length of the zero threshold voltage N-channel FETs increases.

Abstract: A method and apparatus for generating noise to be used in evaluation and testing of digital or analog integrated circuits. One or more noise generators fabricated on a substrate generate noise representative of the digital switching noise generated by a digital integrated circuit. The noise generator may be programmable to generate noise over a wide frequency and amplitude range. In addition, a plurality of noise generators may be used to independently and simultaneously generate noise signals with multiple frequencies and amplitudes. A test circuit, either analog or digital, is fabricated on the same substrate. The generated noise signal(s) are generated for use in the evaluation and testing of the effects of the noise on the analog or digital test circuit.