International Business Machines Corporation

Carroll J Dick

Gregory Scott Still

David L Thomas

Thomas L Jeremiah

Ralph Linsker

Roger Sherman Rutter

Lawrence Jones

Bruce J Ditmyer

Chip performance is measured using LSSD logic to propagate a signal through the LSSD scan path of the chip. The measurement data is compared to tabular data which is used to classify the AC chip performance. The use of the LSSD scan path provides an accurate overall measurement of an entire chip. The circuitry is internal to the system and does not require external test circuitry. No unique test patterns are required for a given chip design. The chip measurements can be made after installation of the chip in a field operational environment as well as during a manufacturing and testing environment. The chip measurements can be made by local execution of the testing or controlled from a remote location.

Calculating AC chip performance using the LSSD scan path

In printed circuit boards having dense printed connections, cross talk noise immunity is significantly improved by preferentially routing adjacent to one another serially connected conductors of the same net rather than conductors of different nets. By such routing inter-net cross talk is reduced while the resultant intra-net cross talk is maintained at tolerable levels.

Routing method and pattern for reducing cross talk noise problems on

An on-chip clock signal generator circuit is disclosed. The clock signal generator generates a high frequency clock signal in response to a system clock developed from a source located at a point external to the chip. The clock generator circuit includes an apparatus for stabilizing the frequency of the clock signal generated by the clock signal generator, this apparatus stabilizing the frequency of the clock signal by minimizing the variation in the position of the intermediate pulses which comprise the clock signal.

Apparatus or method for stabilizing the frequency of a clock signal

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Dryden, NY, United States of America

Carroll J Dick