University of California

Fujitsu Corporation

Hongyu Chen

Chung-Kuan Cheng

Feng Zhou

William Warren Walker

Rajeev Murgai

Bo Yao

Ronald Graham

Esther Y Cheng

Designs and techniques for transmitting electrical signals via transmission lines on integrated circuits without distortion and at the speed of light. In one implementation, one or more leakage resistors are connected between the two conductor wires of a transmission line.

Differential transmission line having a plurality of leakage resistors spaced between the transmission line

In one embodiment, a method includes accessing a description of a chip including multiple sequential elements and a clock mesh, information for modeling the sequential elements and interconnections, and a set of parameters of the clock mesh. The method also includes, using the description of the chip, the information for modeling the sequential elements and interconnections, and the set of parameters of the clock mesh, determining multiple window locations covering the clock mesh. Each window location includes one or more of the sequential elements on the chip. The method also includes, for each window location, generating a mesh simulation model including a detailed model inside the window location and an approximate model outside the window location, simulating the mesh simulation model, and measuring clock timing for the sequential elements in the window location based on the mesh simulation model. The method also includes collecting timing information on the sequential elements on the chip based on the measured clock timing for the sequential elements in the window locations.

Sliding window scheme (SWS) for determining clock timing in a mesh-based clock architecture

The invention is directed to a method for clock distribution and VLSI circuits include a clock distribution network. In a method of the invention, a transmission lines are patterned as to connect a clock tree and a periodic waveform clock, preferably a sine waveform, is used to control clock skew, even at frequencies extending into the gigahertz range. In an exemplary embodiment of the invention, an overlay includes differential pairs of transmission lines that connect the drivers of a clock distribution tree. In preferred embodiments of the invention, an H-tree clock distribution scheme is overlayed with a spiral of transmission lines, each realized by a differential conductors and driven using a sinusoidal standing wave to distribute global clock signals into local regions of the chip. Each transmission line connects drivers in the H-tree that are at the same level of the H-tree. In a VLSI chip according to an embodiment of the invention, the transmission line overlay delivers sinusoidal clock signals to local areas that are locally converted into digital clock signals. The invention thus presents a passive technique for clock distribution.

High speed clock distribution transmission line network

A multi-celled chip. The chip includes a plurality of hexagonal cells arranged in an array. A plurality of interconnects including Y's connect the cells in clusters of three cells each, so that each of the cells is interconnected.

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La Jolla, CA, United States of America

Hongyu Chen