Mentor Graphics Corporation

Other

Randy Klingenberg

Nagesh Tamarapalli

Janusz Rajski

Wu-Tung Cheng

Yu Jane Huang

Thomas Hans Rinderknecht

Chain or logic diagnosis resolution can be enhanced in the presence of limited failure cycles using embodiments of the various methods, systems, and apparatus described herein. For example, pattern sets can be ordered according to a diagnosis coverage figure, which can be used to measure chain or logic diagnosability of the pattern set. Per-pin based diagnosis techniques can also be used to analyze limited failure data.

Enhanced diagnosis with limited failure cycles

A built-in-self-test (BIST) circuit is discussed for selecting tristate nets with substantially uniform distribution using a tristate testing control device (TTCD). The circuit allows the deterministic testing of tristate nets in the context of pseudo-random BIST. A feedback shift register is described that activates a single tristate or set of tristate at a time in order to avoid bus contention. Another TTCD embodiment uses a counter and decoder. A test mode switching unit (TMSU) coupled between the TTCD and the tristate net selects test or functional mode for tristate enables. Parallel multiplexers are discussed as one embodiment of a TMSU. Another TMSU embodiment describes even better test coverage. A method, which may be performed on a distributed computer system, is discussed for identifying tristate nets within a net-list and adding a TTCD and a TMSU to the net-list.

Uniform testing of tristate nets in logic BIST

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Beaverton, OR, United States of America

Randy Klingenberg