Switching activity generation with automated BIST synthesis for performance testing of interconnects

A novel scheme of synthesizing nonlinear feedback shift register structures that can be superimposed on the boundary of the component of a system unde r test to generate interconnect switching activities that resemble real lif e interconnect switching profiles is proposed. The goal is to perform at-sp eed interconnect test while simultaneously capturing the dynamic switching effects such as crosstalk and ground bounce, as accurately as possible duri ng interconnect built-in self-test. A library of nonlinear feedback shift r egister structures called precharacterized test pattern generators (P-TPGs) is constructed. Components of P-TPGs can be modeled using Markov chain and can be interconnected together in specific ways to recreate the switching activity profile of the interconnections being tested. The unique advantage of this scheme is that there is no simulation overhead since P-TPG compone nts are precharacterized by solving Markov equations analytically. An integ rated genetic algorithm-based search and optimization technique for finding the best P-TPG component among various possible implementations and matchi ng its activity profiles with those of the interconnections under test has been designed and implemented. P-TPG synthesis for testability allows gener ation of the worst case interconnect switching activities. Experimental res ults confirm the validity of our approach.