Synopsys, Inc.

Ghassan Khoory

Surrendra A Dudani

Debashis Roy Chowdhury

Pallab Kumar Dasgupta

A technique for observability based coverage of a design under test (DUT) is presented. A conventional simulation signal is augmented to include a 'tag value.' In the course of a simulation, assignment statements (for which observability-based coverage is desired) 'inject' tag values on their output signals. A tag value contains an identifier uniquely identifying the assignment statement that produced it. A tag value also contains a &#x201c;tag history.&#x201d; The tag history contains copies of the tag values for assignment statements earlier in the flow of control or in the flow of data. If a tag propagated through the DUT appears at an observable output, the circuit designer knows that the assignment statements it identifies have satisfied observability based coverage.

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Wellesley, MA, United States of America

Ghassan Khoory