Quiescent current leakage test of the VDD supply (IDDQ Test) has been proven an effective way to screen out defective chips in manufacturing of Integrated Circuits (IC). As technology advances, the traditional IDDQ test is facing more and more challenges. In this research, a practical built-in current sensor (BICS) is proposed and the design is verified by three generations of test chips. The BICS detects the signal by sensing the voltage drop on supply lines of the circuit under test (CUT). Then the sensor performs analog-to-digital conversion of the input signal using a stochastic process with scan chain readout. Self-calibration and digital chopping are used to minimize offset and low frequency noise and drift. This non-invasive procedure avoids any performance degradation of the CUT. The measurement results of test chips are presented. The sensor achieves a high IDDQ resolution with small chip area overhead. This will enable IDDQ of future technology generations.

IDDQ testing has been a very useful test screen for CMOS circuits. However, with each technology node the background leakage of chips is rapidly increasing. As a result it is becoming more difficult to distinguish between faulty and fault-free chips using IDDQ testing. Power supply partitioning has been proposed to increase test resolution by partitioning the power supply network, such that each partition has a relatively small defect-free IDDQ level. However, at present no practical partitioning strategy is available. The contribution of this thesis is to present a practical power supply partitioning strategy. We formulate various versions of the power supply partitioning problem that are likely to be of interest depending on the constraints of the chip design. Solutions to all the variants of the problem are presented. The basic idea behind all solutions is to abstract the power topology of the chip as a flow network. We then use flow techniques to find the min-cut of the transformed network to get solutions to our various problem formulations. Experimental results for benchmark circuits verify the feasibility of our solution methodology. The problem formulations will give complete flexibility to a test engineer to decide which factors cannot be compromised (e.g. area of BICS, test quality, etc) for a particular design and accordingly choose the appropriate problem formulation. The application of this work will be the first step in the placement of Built-In Current Sensors for IDDQ testing.

Faculty of Humanities School of Human and Community Development/Psychology 9503776d Kajeean@educ.wits.ac.za / This study investigated English Second Language (ESL) students’ experiences of academic writing in a tertiary institution. It focused particularly on ESL students’ interpretations of what is expected in academic writing. Consequently, ESL students’ expectations were compared and contrasted to the academic writing expectations of a group of academics in the same institution. The study aimed to explore how the concepts of Basic Interpersonal Communicative Skills (BICS) and Cognitive Academic Language Proficiency (CALP) were manifest in the students’ expectations and writing. The main aim was to identify the BICS and CALP distinction in ESL students as explanatory of their ability to write academically. In other words, the assumption was that ESL students experience difficulty with writing because they achieve surface fluency in terms of BICS but do not seem to develop sufficient levels of CALP to cope with the demands of the curricula in academic study. The sample consisted of thirty first year ESL Psychology students and six academics who taught on the first year Psychology course. ESL student volunteers were organized into focus groups, while academics were asked to participate in semi-structured, individual interviews. The participants’ responses were recorded and subsequently analyzed using thematic content analysis. It was found that academic writing was conceptualized in terms of structure and content. Through this distinction, ESL students recognized that, although they are able to operate at surface levels of language proficiency they find it problematic to operate at deeper levels of cognitive academic language proficiency. This in turn explained why they found it difficult to perform higher order academic tasks that go beyond the rote recall of content to analysis, synthesis, evaluation and application of concepts and theory. Further findings were extrapolated that lie at the level of the ESL student and the tertiary institution. It was found that academic writing expectations needed to be communicated to students by academics in more distinct terms. The internalization of academic discourse by ESL students, and students in general, seemed to require further facilitation by academics in the tertiary community of practice. Furthermore, the study raised the issue of English Second Language as a label impacting on ESL student’s confidence, self-esteem and overall attitude towards transcending challenges associated with academic writing.

The aim of this essay was to investigate whether pupils with higher grades based on formative assessment were more successful at adapting informal texts into formal texts.Six pupils in English 7 were asked to write an informal blog entry about their favorite hobby/pastime and a formal entry also about their favorite hobby/pastime intended for an English encyclopedia. The pupils that were selected were assessed as havingformative grades A-E. The ability to transform informal into formal texts was assessedquantitatively by counting a number of lexical and grammatical features. The results showed that pupils with a higher formative grade did not experience significant difficulties in adapting their language and switching from informal to formal language. The results also showed that the usage of slang and contractions among the pupils with lower grades was maximized.

<p>I denna studie undersöks hur några före detta IVIK–elever har lyckats med sina gymnasiestudier på ett treårigt nationellt program. Jag har intervjuat fyra informanter, två flickor som läser sitt andra år och två pojkar som läser sitt tredje och sista år. Viktigt att påpeka är att de elever som intervjuats i denna studie är mycket ambitiösa och målmedvetna och att det endast genom dessa fyra fallstudier är omöjligt att dra några generella slutsatser. Genom intervjuer och analys av informanternas betyg kan konstateras att just dessa har lyckats väl med sina valda programstudier. Det språkliga inflödet, stöttning och motivation är några av de faktorer som informanterna har gemensamt och som bidragit till deras goda studieresultat. I mångt och mycket stämmer den litteratur som finns om andraspråksinlärning och studieframgång väl in på mina informanter. <strong></strong></p>

Chaque actionneur d'un système sécuritaire doit être contrôlé par un signal sûr en présence de défaillance (fail-safe), c'est-à-dire qu'en cas de défaillance son état est soit correct, soit sûr. Les systèmes intégrés auto-contrôlables en ligne (self-checking) fournissent des groupes de signaux codés en sortie. Ces groupes de signaux ne permettent pas d'assurer le contrôle direct des actionneurs, car chaque actionneur est contrôlé par un seul signal qui doit être individuellement sûr. A cause de cette exigence particulière, il n'était pas possible d'implémenter en VLSI toutes les parties : un système auto contrôlé (self-checking) ou tolérant aux pannes (qui utilise par exemple un code détecteur d'erreur, une technique de duplication, triplication ou un processeur codé), et une interface fail-safe utilisant des composants discrets. Cette interface transforme les sorties du système de traitement en signaux fail-safe. Outre l'inconvénient des interfaces à composants discrets d'être très encombrantes et coûteuses, la probabilité de défaillance est augmentée et la durée de vie (MTTF) du système est diminuée dans ce cas par rapport à l'implémentation VLSI, ce qui limite la disponibilité du système. Il est donc intéressant d'intégrer en VLSI les interfaces fail-sage, capables d'assurer le contrôle sécuritaire des actionneurs. Dans ce mémoire, nous présentons une interface sécurisée de puissance réalisée en technologie de puissance intelligente. Cette interface transforme les signaux de contrôles codés en fréquence en signaux de puissance pour le contôle sécuritaire des actionneurs dans les transports ferroviaires. Elle repose sur l'utilisation du concet de fail-safe, et d'autocontrôlable pour atteintre un haut niveau de sécurité.

Neste trabalho foi elaborado um microcontrolador 8051 tolerante à radiação, usando para isso técnicas de recomputação de instruções. A base para este trabalho foi a descrição VHDL desse microcontrolador, sendo proposto o uso de sensores de radiação, Bulk-BICS, e códigos de proteção de erros para os elementos de memória, como forma de suporte à técnica apresentada. Inicialmente serão abordados sucintamente a origem e os efeitos prejudiciais da radiação nos dispositivos eletrônicos, motivando a realização deste trabalho. Serão mostrados em detalhes os passos para implementar a técnica de recomputação, que consiste em monitorar os sensores e, ao ser detectado um pulso transiente, fazer o processador reler a última instrução e executá-la novamente, a fim de mitigar o efeito do SET (Single Event Transient). Para isso a manipulação do contador de programa (PC) e o apontador de pilha (SP) são fundamentais. Durante esse processo também deve ser garantido que nenhum dado, potencialmente corrompido, seja armazenado na memória. Contra SEUs (Single Event Upsets) é pressuposto que todos os elementos de memória do microcontrolador estão protegidos através de algum código de correção de erros, assunto já pesquisado por outros autores. Na seqüência serão apresentadas várias simulações realizadas, onde é possível ver o processo de recomputação sendo iniciado a partir da incidência de partículas geradas através de um testbench. Por fim será feita uma comparação entre o 8051 original e o protegido, mostrando dados de área, freqüência de operação e potência de cada um. / This work presents a radiation hard 8051 microcontroller, designed using instruction recomputation techniques. The basis for this work was the VHDL description of the microcontroller. To make the microcontroller radiation hard, built in radiation sensors, called Bulk-BICS, were use to protect the combinational logic blocks. Codes for error detection and correction were used to protect the memory elements. Initially, this work discusses the sources of ionizing radiation and its harmful effects on digital integrated circuits, showing the motivation for this work. Next, the details of the implemented instruction re-computation technique are shown. It consists in monitoring the radiation sensors and, if the incidence of ionizing radiation is detected, the processor reads the last instruction and executes it again, in order to mitigate the effect of a single event transient (SET). In order to implement this re-computation, the manipulation of the program counter (PC) and stack pointer (SP) is essential. During this process it must be guaranteed that any data, potentially corrupted, will not be stored in memory. Regarding radiation effects on memory elements (Single Event Upsets-SEUs), it is assumed that all memory elements of the microcontroller are protected by some error detection and correction code, a topic previously studied by other authors. Finally, several simulations will be shown, where it is possible to see the evolution of the re-computation process, from the detection of the incidence of ionizing radiation (incidence generated by a testbench) to the full re-computation of the instruction. Finally, a comparison is made between the performance of the original 8051 and the radiation hardened version, showing overheads of area, frequency of operation and power.

Neste trabalho foi elaborado um microcontrolador 8051 tolerante à radiação, usando para isso técnicas de recomputação de instruções. A base para este trabalho foi a descrição VHDL desse microcontrolador, sendo proposto o uso de sensores de radiação, Bulk-BICS, e códigos de proteção de erros para os elementos de memória, como forma de suporte à técnica apresentada. Inicialmente serão abordados sucintamente a origem e os efeitos prejudiciais da radiação nos dispositivos eletrônicos, motivando a realização deste trabalho. Serão mostrados em detalhes os passos para implementar a técnica de recomputação, que consiste em monitorar os sensores e, ao ser detectado um pulso transiente, fazer o processador reler a última instrução e executá-la novamente, a fim de mitigar o efeito do SET (Single Event Transient). Para isso a manipulação do contador de programa (PC) e o apontador de pilha (SP) são fundamentais. Durante esse processo também deve ser garantido que nenhum dado, potencialmente corrompido, seja armazenado na memória. Contra SEUs (Single Event Upsets) é pressuposto que todos os elementos de memória do microcontrolador estão protegidos através de algum código de correção de erros, assunto já pesquisado por outros autores. Na seqüência serão apresentadas várias simulações realizadas, onde é possível ver o processo de recomputação sendo iniciado a partir da incidência de partículas geradas através de um testbench. Por fim será feita uma comparação entre o 8051 original e o protegido, mostrando dados de área, freqüência de operação e potência de cada um. / This work presents a radiation hard 8051 microcontroller, designed using instruction recomputation techniques. The basis for this work was the VHDL description of the microcontroller. To make the microcontroller radiation hard, built in radiation sensors, called Bulk-BICS, were use to protect the combinational logic blocks. Codes for error detection and correction were used to protect the memory elements. Initially, this work discusses the sources of ionizing radiation and its harmful effects on digital integrated circuits, showing the motivation for this work. Next, the details of the implemented instruction re-computation technique are shown. It consists in monitoring the radiation sensors and, if the incidence of ionizing radiation is detected, the processor reads the last instruction and executes it again, in order to mitigate the effect of a single event transient (SET). In order to implement this re-computation, the manipulation of the program counter (PC) and stack pointer (SP) is essential. During this process it must be guaranteed that any data, potentially corrupted, will not be stored in memory. Regarding radiation effects on memory elements (Single Event Upsets-SEUs), it is assumed that all memory elements of the microcontroller are protected by some error detection and correction code, a topic previously studied by other authors. Finally, several simulations will be shown, where it is possible to see the evolution of the re-computation process, from the detection of the incidence of ionizing radiation (incidence generated by a testbench) to the full re-computation of the instruction. Finally, a comparison is made between the performance of the original 8051 and the radiation hardened version, showing overheads of area, frequency of operation and power.

Neste trabalho foi elaborado um microcontrolador 8051 tolerante à radiação, usando para isso técnicas de recomputação de instruções. A base para este trabalho foi a descrição VHDL desse microcontrolador, sendo proposto o uso de sensores de radiação, Bulk-BICS, e códigos de proteção de erros para os elementos de memória, como forma de suporte à técnica apresentada. Inicialmente serão abordados sucintamente a origem e os efeitos prejudiciais da radiação nos dispositivos eletrônicos, motivando a realização deste trabalho. Serão mostrados em detalhes os passos para implementar a técnica de recomputação, que consiste em monitorar os sensores e, ao ser detectado um pulso transiente, fazer o processador reler a última instrução e executá-la novamente, a fim de mitigar o efeito do SET (Single Event Transient). Para isso a manipulação do contador de programa (PC) e o apontador de pilha (SP) são fundamentais. Durante esse processo também deve ser garantido que nenhum dado, potencialmente corrompido, seja armazenado na memória. Contra SEUs (Single Event Upsets) é pressuposto que todos os elementos de memória do microcontrolador estão protegidos através de algum código de correção de erros, assunto já pesquisado por outros autores. Na seqüência serão apresentadas várias simulações realizadas, onde é possível ver o processo de recomputação sendo iniciado a partir da incidência de partículas geradas através de um testbench. Por fim será feita uma comparação entre o 8051 original e o protegido, mostrando dados de área, freqüência de operação e potência de cada um. / This work presents a radiation hard 8051 microcontroller, designed using instruction recomputation techniques. The basis for this work was the VHDL description of the microcontroller. To make the microcontroller radiation hard, built in radiation sensors, called Bulk-BICS, were use to protect the combinational logic blocks. Codes for error detection and correction were used to protect the memory elements. Initially, this work discusses the sources of ionizing radiation and its harmful effects on digital integrated circuits, showing the motivation for this work. Next, the details of the implemented instruction re-computation technique are shown. It consists in monitoring the radiation sensors and, if the incidence of ionizing radiation is detected, the processor reads the last instruction and executes it again, in order to mitigate the effect of a single event transient (SET). In order to implement this re-computation, the manipulation of the program counter (PC) and stack pointer (SP) is essential. During this process it must be guaranteed that any data, potentially corrupted, will not be stored in memory. Regarding radiation effects on memory elements (Single Event Upsets-SEUs), it is assumed that all memory elements of the microcontroller are protected by some error detection and correction code, a topic previously studied by other authors. Finally, several simulations will be shown, where it is possible to see the evolution of the re-computation process, from the detection of the incidence of ionizing radiation (incidence generated by a testbench) to the full re-computation of the instruction. Finally, a comparison is made between the performance of the original 8051 and the radiation hardened version, showing overheads of area, frequency of operation and power.

Studien baseras på en kvalitativ och kvantitativ läromedelsanalys med fokus på språkliga svårigheter i de naturorienterande ämnena för årskurs 1–3 samt årskurs 4 och 5. Syftet med studien var att belysa om läromedel i NO är anpassade för elever som läser svenska som andraspråk. Studiens forskningsfrågor var; ”Vilka språkliga svårigheter finns i de valda läromedlen samt i vilken utsträckning förekommer de?”, ”Vilket stöd finns i de valda läromedlen för att hantera de språkliga svårigheterna?” och ”Hur ser progressionen i läromedlen ut mellan årskurserna?”. De valda läromedlen för denna läromedelsanalys är PULS NO-boken 1–3, Boken om NO 1–3, PULS NO 4 och Koll på NO 5. Analysen genomfördes på 4 sidor i vardera naturorienterande ämne i varje läromedel. Flerspråkiga elever som inte fullt ut har utvecklat det svenska språket möter en del svårigheter gällande de naturorienterande ämnena. De olika språkliga svårigheterna som analyserades i studien var begrepp i utkanten av en semantisk mellannivå, homonymer, nominaliseringar och andra ämnesspecifika begrepp. Analysen utgick ifrån två teoretiska utgångspunkter: BICS och CALP samt text och bild i läromedel.  Resultatet visade att läromedlen i NO för dessa årskurser innehåller språkliga svårigheter där en del begrepp saknar visuellt stöd eller språkliga förtydliganden som kan hjälpa flerspråkiga elever att förstå innehållet. Denna studies resultat stämmer till en viss del överens med tidigare forskning. Slutsatsen i denna studie är att dessa läromedel innehåller begrepp som kan uppfattas som svåra för flerspråkiga elever och att lärare behöver vara medvetna om detta för att utforma undervisningen för att förbereda eleverna för dessa begrepp med en närmare förklaring som introduktion.