Synopsys, Inc.

Gregory A Maston

Peter Wohl

John A Waicukauski

Frederic J Neuveux

A scan test system and technique compresses CARE bits and X-control input data into PRPG seeds, thereby providing a first compression. The scan test system includes a plurality of compressor and decompressor structures (CODECs). Each block of the design includes at least one CODEC. An instruction decode unit (IDU) receives scan inputs and determines whether a seed extracted from the scan inputs is broadcast loaded in the CODECs, multicast loaded in a subset of the CODECs, or individual loaded in a single CODEC. This sharing of seeds, exploits the hierarchical nature of large designs with many PRPGs, provides a second compression. Results on large industrial designs demonstrate significant data and cycle compression increases while maintaining test coverage, diagnosability, and performance.

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Denver, CO, United States of America

Gregory A Maston