Maximizing Crosstalk-Induced Slowdown During Path Delay Test

Capacitive crosstalk between adjacent signal wires in integrated circuits may lead to noise or a speedup or slowdown in signal transitions. These in turn may lead to circuit failure or reduced operating speed. This thesis focuses on generating test patterns to induce crosstalk-induced signal delays, in order to determine whether the circuit can still meet its timing specification. A timing-driven test generator is developed to sensitize multiple aligned aggressors coupled to a delay-sensitive victim path to detect the combination of a delay spot defect and crosstalk-induced slowdown. The framework uses parasitic capacitance information, timing windows and crosstalk-induced delay estimates to screen out unaligned or ineffective aggressors coupled to a victim path, speeding up crosstalk pattern generation. In order to induce maximum crosstalk slowdown along a path, aggressors are prioritized based on their potential delay increase and timing alignment. The test generation engine introduces the concept of alignment-driven path sensitization to generate paths from inputs to coupled aggressor nets that meet timing alignment and direction requirements. By using path delay information obtained from circuit preprocessing, preferred paths can be chosen during aggressor path propagation processes. As the test generator sensitizes aggressors in the presence of victim path necessary assignments, the search space is effectively reduced for aggressor path generation. This helps in reducing the test generation time for aligned aggressors. In addition, two new crosstalk-driven dynamic test compaction algorithms are developed to control the increase in test pattern count. The proposed test generation algorithm is applied to ISCAS85 and ISCAS89 benchmark circuits. SPICE simulation results demonstrate the ability of the alignment-driven test generator to increase crosstalk-induced delays along victim paths

An advanced Framework for efficient IC optimization based on analytical models engine

En base als reptes sorgits a conseqüència de l'escalat de la tecnologia, la present tesis desenvolupa i analitza un conjunt d'eines orientades a avaluar la sensibilitat a la propagació d'esdeveniments SET en circuits microelectrònics. S'han proposant varies mètriques de propagació de SETs considerant l'impacto dels emmascaraments lògic, elèctric i combinat lògic-elèctric. Aquestes mètriques proporcionen una via d'anàlisi per quantificar tant les regions més susceptibles a propagar SETs com les sortides més susceptibles de rebre'ls. S'ha desenvolupat un conjunt d'algorismes de cerca de camins sensibilitzables altament adaptables a múltiples aplicacions, un sistema lògic especific i diverses tècniques de simplificació de circuits. S'ha demostrat que el retard d'un camí donat depèn dels vectors de sensibilització aplicats a les portes que formen part del mateix, essent aquesta variació de retard comparable a la atribuïble a les variacions paramètriques del proces.En base a los desafíos surgidos a consecuencia del escalado de la tecnología, la presente tesis desarrolla y analiza un conjunto de herramientas orientadas a evaluar la sensibilidad a la propagación de eventos SET en circuitos microelectrónicos. Se han propuesto varias métricas de propagación de SETs considerando el impacto de los enmascaramientos lógico, eléctrico y combinado lógico-eléctrico. Estas métricas proporcionan una vía de análisis para cuantificar tanto las regiones más susceptibles a propagar eventos SET como las salidas más susceptibles a recibirlos. Ha sido desarrollado un conjunto de algoritmos de búsqueda de caminos sensibilizables altamente adaptables a múltiples aplicaciones, un sistema lógico especifico y diversas técnicas de simplificación de circuitos. Se ha demostrado que el retardo de un camino dado depende de los vectores de sensibilización aplicados a las puertas que forman parte del mismo, siendo esta variación de retardo comparable a la atribuible a las variaciones paramétricas del proceso.Based on the challenges arising as a result of technology scaling, this thesis develops and evaluates a complete framework for SET propagation sensitivity. The framework comprises a number of processing tools capable of handling circuits with high complexity in an efficient way. Various SET propagation metrics have been proposed considering the impact of logic, electric and combined logic-electric masking. Such metrics provide a valuable vehicle to grade either in-circuit regions being more susceptible of propagating SETs toward the circuit outputs or circuit outputs more susceptible to produce SET. A quite efficient and customizable true path finding algorithm with a specific logic system has been constructed and its efficacy demonstrated on large benchmark circuits. It has been shown that the delay of a path depends on the sensitization vectors applied to the gates within the path. In some cases, this variation is comparable to the one caused by process parameters variation