Abstract: A method and apparatus to determine skew of an on-chip signal without physical probing of the on-chip signal on the chip is provided. The method and apparatus use an externally generated reference signal that is distributed to one or more on-chip samplers that input the on-chip signal. Then, by modulating the externally generated reference signal, transitions of the on-chip signal can be detected at the one or more on-chip samplers so that the skew of the on-chip signal can be determined.

Abstract: A method for synchronizing a data signal and a clock signal has been developed. The method first generates two separate intermediate data signals. The intermediate data signals lag the input data signal. The separate durations of the two lagging signals are combined to form an output data signal that is synchronized with the system clock signal.

Abstract: A method for reducing global clock skew by referencing a first point on an integrated circuit to which to align other points on the integrated circuit is provided. Further, an integrated circuit that has localized DLLs having adjustable buffers that selectively drive a signal on a clock grid is provided. Further, a technique for using a local DLL, one or more phase detectors, and one or more DLLs connected to portions of a clock grid to reduce clock skew is provided.

Abstract: A method and apparatus for stretching and/or shortening a clock cycle uses a multiplexor stage, in which a multiplexor switches between a normal clock signal and a delayed clock signal. Further, a method and apparatus for generating a plurality of stretched and/or shortened clock cycles uses a multiplexor stage in which a multiplexor successively switches between a normal clock signal and a plurality of delayed clock signals. Further, a method and apparatus for removing a clock cycle uses a multiplexor stage, in which a multiplexor switches between either a normal clock signal or a delayed clock signal and a grounded signal.

Abstract: A method and apparatus for reducing clock skew by isolating power distribution to a clock tree from chip logic is provided. Further, the present invention uses separate leads through a circuit board to distribute power from a power supply to a clock tree and a chip logic.

Abstract: A method and apparatus to determine skew of an on-chip signal without physical probing of the on-chip signal on the chip is provided. The method and apparatus use an externally generated reference signal that is distributed to one or more on-chip samplers that input the on-chip signal. Then, by modulating the externally generated reference signal, transitions of the on-chip signal can be detected at the one or more on-chip samplers so that the skew of the on-chip signal can be determined.

Abstract: An automated shielding tool, algorithm, and design methodology for shielding integrated circuits is disclosed herein. This is accomplished by inserting VDD and VSS wire proximate to signal wires on the same metal layer. The noise issues for dynamic circuits is described along with the benefits and costs of wire shielding. The methodology of the shield tool is a systematic approach for dealing with noise due to capacitive and inductive coupling.

Abstract: A method and apparatus for stretching and/or shortening a clock cycle uses a multiplexor stage, in which a multiplexor switches between a normal clock signal and a delayed clock signal. Further, a method and apparatus for generating a plurality of stretched and/or shortened clock cycles uses a multiplexor stage in which a multiplexor successively switches between a normal clock signal and a plurality of delayed clock signals. Further, a method and apparatus for removing a clock cycle uses a multiplexor stage, in which a multiplexor switches between either a normal clock signal or a delayed clock signal and a grounded signal.

Abstract: A method for dividing a high frequency clock signal for analysis of all clock edges has been developed. The method includes receiving a high frequency clock signal and dividing it up into multiple phases that represent respective edges of the clock signal. The initial phases are generated by the divider with each subsequent phase lagging its preceding phase by one clock cycle. Additional subsequent phases are generated by inverting corresponding initial phases.

Abstract: A dynamic flip-flop circuit that operates in a pre-charge phase and an evaluation phase allows for implementation of multiple-input logic functions without sacrificing performance by using a single evaluation path to generate its output signals. In one embodiment, the dynamic flip-flop circuit includes input logic that receives a clock signal and one or more data input signals. The clock signal defines the pre-charge phase and the evaluation phase of the flip-flop circuit. The input logic has an output terminal connected to a first output buffer circuit, which in turn drives the flip-flop circuit's Q output signal. The output terminal of the input logic is combined with the clock signal in a logic gate having an output terminal connected to a second output buffer circuit, which in turn drives the flip-flop circuit's complementary output signal {overscore (Q)}.