Considerable research has been directed towards efficient test stimuli generation for Register Transfer Level (RTL) circuits. However, stimuli generation frameworks are still not capable of generating effective stimuli for all circuits. Some of the limiting factors are 1) It is hard to ascertain if a branch in the RTL code is reachable, and 2) Some hard-to-reach branches require intelligent algorithms to reach them. Since unreachable branches cannot be reached by any test sequence, we propose a method to deduce unreachability of a branch by looking for the possible values which a signal can take in an RTL code without explicit unrolling of the design. To the best of our knowledge, this method has been able to identify more unreachable branches than any method published in this domain, while being computationally less expensive. Moreover, some branches require very specific values on input signals in specific cycles to reach them. Conventional symbolic execution can generate those values but is computationally expensive. We propose a cycle-by-cycle restrictive symbolic execution that analyzes only a selected subset of program statements to reduce the computational cost. Our proposed method gathers information from an initial execution trace generated by any technique, to intelligently decide specific cycles where the application of this method will be helpful. This method can hybrid with simulation-based test stimuli generation methods to reduce the cost of formal verification. With this method, we were able to reach some previously unreached branches in ITC99 benchmark circuits. / Master of Science

Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-10-26T19:04:54Z No. of bitstreams: 1 DissFLC.pdf: 1637955 bytes, checksum: b94dbdba30fb59739948038e7cc356cf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:30:42Z (GMT) No. of bitstreams: 1 DissFLC.pdf: 1637955 bytes, checksum: b94dbdba30fb59739948038e7cc356cf (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-11-08T18:30:48Z (GMT) No. of bitstreams: 1 DissFLC.pdf: 1637955 bytes, checksum: b94dbdba30fb59739948038e7cc356cf (MD5) / Made available in DSpace on 2016-11-08T18:30:55Z (GMT). No. of bitstreams: 1 DissFLC.pdf: 1637955 bytes, checksum: b94dbdba30fb59739948038e7cc356cf (MD5) Previous issue date: 2016-09-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / We introduce some geometric experiments to the students, and particularly the handling of right-angled triangles, with the clear purpose of inserting, firming and emphasizing the importance, historical and practical, of the concept and meaning of the geometric tangent in an entire acute angle in triangle. Later, the students built a rudimentary theodolite that was used to measure vertical angles of tops inaccessible objects from the ground and consequently the estimate of their heights. The prospect objects were trees, poles, masts, antennas, spotlights, among other more familiar to the students of the ninth grade in elementary school. / Neste trabalho apresentamos aos alunos alguns experimentos geométricos e, sobretudo, a manipulação de triângulos retângulos, com o claro objetivo de inserir, fixar e ressaltar a importância, histórica e prática, do conceito e do significado geométrico da tangente de um ângulo agudo. Posteriormente, os alunos construíram um teodolito rudimentar que foi utilizado para medir ângulos verticais de topos de objetos inacessíveis em relação ao solo e consequentemente o cálculo de suas alturas. Os objetos explorados foram árvores, postes, mastros, antenas, refletores, entre outros mais familiares para os estudantes do nono ano do Ensino Fundamental.

The aim of this work is an optimization of AHLL language compiler. Several intermediate representations of compiled code along with code optimization techniques are introduced. The main part of the work is focused on implementing these optimization techniques and generation of the target code in ALLL language. At the end of the work, the results achieved by new version of AHLL compiler are presented. In addition, there are also presented some ideas for the future work on AHLL and the compiler.