Abstract: Embodiments of the present invention include a method for fabricating a hybrid land grid array connector and the resulting structures. A body is provided. The body includes a first plurality of holes and a second plurality of holes. A conductive layer is deposited on the top and bottom surfaces of the body and the wall surfaces of the first plurality of holes resulting in the top and bottom surfaces being electrically common. The conductive layer is removed from the wall surfaces of a first subset of the first plurality of holes. A portion of the conductive layer is removed from the top surface of the body and the bottom surface of the body from an area surrounding the first subset of the first plurality of holes.

Abstract: Embodiments of the present invention include a method for fabricating a hybrid land grid array connector and the resulting structures. A body is provided. The body includes a first plurality of holes and a second plurality of holes. A conductive layer is deposited on the top and bottom surfaces of the body and the wall surfaces of the first plurality of holes resulting in the top and bottom surfaces being electrically common. The conductive layer is removed from the wall surfaces of a first subset of the first plurality of holes. A portion of the conductive layer is removed from the top surface of the body and the bottom surface of the body from an area surrounding the first subset of the first plurality of holes.

Abstract: A regulated delay line device includes main regulator coupled to a node, and a plurality of delay branches coupled to the node to receive a voltage output to the node by the main regulator. Each of the plurality of delay branches includes a micro-regulator and a delay line. The delay line is coupled to the micro-regulator such that unfiltered noise is removed locally at each delay branch by a corresponding micro-regulator.

Abstract: A regulated delay line device includes main regulator coupled to a node, and a plurality of delay branches coupled to the node to receive a voltage output to the node by the main regulator. Each of the plurality of delay branches includes a micro-regulator and a delay line. The delay line is coupled to the micro-regulator such that unfiltered noise is removed locally at each delay branch by a corresponding micro-regulator.

Abstract: A signal history controlled slew-rate transmission method and bus interface transmitter provide an improved channel equalization mechanism having low complexity. A variable slew-rate feed-forward pre-emphasis circuit changes the slew rate of the applied pre-emphasis in conformity with the history of the transmitted signal. The pre-emphasis circuit may be implemented by a pair of current sources supplying the output of the transmitter, and having differing current values. The current sources are controlled such that upon a signal value change, a high slew rate is provided and when the signal value does not change for two consecutive signal periods, the slew rate is reduced. A current source having a controlled magnitude may be employed to provide a slew rate that changes over time and is continuously reduced until another transmission value change occurs.

Abstract: A method, apparatus, and computer instructions for managing a set of signal paths for a chip. A defective signal path within the set of signal paths for the chip is detected. Signals are re-routed through the set of signal paths such that the defective signal path is removed from the set of signal paths and sending signals using remaining data signal paths in the set of signal paths and using an extra signal path in response to detecting the defective signal path.

Abstract: A dual inline memory module (DIMM) includes a card having a length of about 151.2 to about 151.5 millimeters, a plurality of individual local memory devices attached to the card, and a buffer device attached to the card, the buffer device configured for converting a packetized memory interface. The card includes at least 276 pins configured thereon including a plurality of high-speed bus interface pills arranged on said card for communicating with a plurality of high-speed busses. The high-speed bus interface pins associated with a single high-speed bus are located on one side of the card with respect to a midpoint of the length of the card, thus the pin assignments are defined such that the performance of the DIMM in a system is optimized for high frequency operation.

Abstract: A dual inline memory module (DIMM) includes a card having a length of about 151.2 to about 151.5 millimeters, a pluality of individual local memory devices attached to the card, and a buffer device attached to the card, the buffer device configured for converting a packetized memory interface. The card includes at least 276 pins configured thereon.

Abstract: Signaling between two or more ICs use a signaling scheme wherein a reference signal is generated at the driver side and the receiver side. The driver side reference signal is coupled to the receiver side reference signal with a transmission line channel forming a reference channel. Data signal channels are paired with a reference channel between each two adjacent data channels. Adjacent pairs of data signal channels are each separated with an empty wiring channel. The paired data signals are received in one input of a differential receiver. The reference signal of the reference channel between the two paired data channels is coupled to the other input of the two differential receivers. Coupling from the paired data channels to the reference channel appears a common mode noise and is rejected by the differential receivers. The number of channels is reduced from a full differential signaling scheme.

Abstract: Delay elements and delay lines having glitchless operation are disclosed. By way of example, apparatus for delaying an input signal comprises a reference current generator for generating a constant current, wherein the constant current is insensitive to a variation of a power supply voltage, at least one variable bias voltage generator coupled to the reference current generator for generating a set of bias voltages based on the constant current generated by the reference current generator and a digitally programmable delay control input, and at least one delay element coupled to the at least one variable bias voltage generator for delaying the input signal by a constant delay which is determined by the set of bias voltages generated by the at least one variable bias voltage generator.

Abstract: A mechanism for de-skewing and aligning data bits sent between two chips on an elastic interface. On the receiving end of an elastic interface, the eye of each data bit within a clock/data group is delayed by less than a bit time to align the eyes with the nearest clock edge of a received clock signal. In addition to aligning the eyes of the individual data bits with the nearest clock edge, IAP patterns are used to determine the amount of further delay needed to line up the individual data beats from each data bit. If the data beats for the data bits are not aligned, all but the slowest data beat are delayed to align the data beats for all bits. The additional delay is achieved using sample latches that result in a delayed signal with less jitter. As a result of having less jitter, the received, de-skewed, and aligned clock/data group can be forwarded to the operative portion of the receiving chip at an increased frequency.

Abstract: A digitally tunable low voltage CMOS current reference is disclosed. A tunable current reference circuit is provided that includes a current source circuit that is coupled to a power supply voltage. The current source circuit provides a stable current reference output regardless of fluctuations in the power supply voltage. Multiple digitally selectable inputs are included in the current reference circuit and are coupled to the current source circuit. These inputs are used to adjust a value of the current reference output.

Abstract: Pseudo-differential drivers and receivers are used to communicate data signals between two or more IC chips. The data paths are aligned using programmable delay circuitry to de-skew each data path. A programmable reference generator is used to generate a reference voltage used by one or a group of receivers to detect the data signals. The reference voltage is adjustable using coarse as well as fine digitally controlled voltage increments. Test signals are sent from the driver to the receiver and the reference voltage is varied over its adjustable range using the coarse and fine adjustment controls while circuitry determines a measure of the detection timing jitter on successive transitions of the test signal. The operational value of the reference voltage is set to the value where the detection timing jitter is determined to be a minimum.

Abstract: The slew rate of signals output from an integrated circuit is selectively controlled to optimize the quality of the output data signal depending upon whether the communication channels require a faster or slower slew rate. Faster slew rates may be utilized when the communication channels are prone to attenuation, while slower slew rates may be implemented in the communication channels when crosstalk is more of a concern.

Abstract: A receiver circuit is configured as a frequency compensated differential amplifier having one input coupled to the output of a transmission line to receive a transmitted signal and the second input coupled to a reference voltage. The differential amplifier has a high frequency gain equivalent to the gain of an uncompensated differential stage for the transmitted signal. The compensated differential amplifier has an attenuated low frequency gain for signal frequencies substantially lower than the high frequency and a transitional gain for frequencies between the low and high frequencies. A compensated stage provides the portion of the signal with a compensated response and an uncompensated stage provides the portion of the amplified signal that is uncompensated. Bias control signals determine how much of the output signal is from the compensated and uncompensated stages as a means for customizing response from transmission lines with varying losses.

Abstract: Data signals are transmitted over transmission lines in groups to receivers in a receiving IC. Each group of data signals has a differential clock used in synchronizing and detecting the data signals. The data signal eye windows vary with timing jitter in the data signals relative to the clock edges and the asymmetry in a compensated clock signal detected from the differential clock using a duty cycle adjustment circuit. Error detection determines if the clock asymmetry is affecting the eye window of the data signals. Control signals selectively adjust the gain of differential stages generating the compensated clock to modify the duty cycle of the compensated clock. The eye window of the data signals are monitored and used as feedback to servo the control signals to optimize the duty cycle of the compensated clock signal for sampling the data signals.

Abstract: A method and apparatus for de-skewing and aligning digital data received over and elastic interface bus is disclosed. Upon receiving the data, it is sent through a programmable delay line. While in the programmable delay line, the data is sampled at three points within the data's eye pattern. The three sampling points are dynamically adjusted to maximize coverage of the data's eye pattern. During the adjustment of the sampling points to optimally cover the data's eye pattern, delayed data is sampled from an alternate sampler to prevent sampling from the functional sampler while the delay in the primary sampler is adjusted. Sampling from the alternate sampler while changing the sampling points of the functional sampler serves to reduce glitches that may occur by sampling the functional sampler while its sampling parameters are changed. The method and apparatus allow for alternate eye tracking and wraparound eye tracking.

Abstract: A line driver for off-chip communication comprises multiple parallel stages each with separate inputs. The parallel stages each have a controlled impedance when driving the line driver output node to a logic zero or a logic one. A line driver controller is used to select what combination of driver stages are used to drive the output node based on whether the output node is transitioning between logic state or is remaining static. During power-up, a test program tries different combinations of driver stages for particular symbol patterns and determines what is the optimal ratio between line driver resistance for the dynamic and static cases and stores the optimum combination. The data stream feeding the line driver is sampled in real time to determine the transition states and selects the optimal number of driver stages for each case.

Abstract: A power supply voltage insensitive delay element is provided that enables a digital signal to be delayed without variation due to power supply vulnerabilities. Current is limited through the transistors of the delay element using bias voltages produced by a bias voltage generator coupled to the delay element. The bias voltage generator and the delay element are included in a delay line which facilitates the providing of a delay that is insensitive to voltage fluctuations.

Abstract: The on-chip power supply noise sensor detects high frequency overshoots and undershoots of the power supply voltage. By creating two identical current sources and attaching a time constant circuit to only one, the high frequency transient behavior differs while the low frequency behavior is equivalent. By comparing these currents, the magnitude of very high frequency power supply noise can be sensed and used to either set latches or add to a digital counter. This has the advantage of directly sensing the power supply noise in a manner that does not require calibration. Also, since the sensor requires only one power supply, it can be used anywhere on a chip. Finally, it filters out any lower frequency noise that is not interesting to the circuit designer and can be tuned to detect down to whatever frequency is needed.