Early Estimation Of The Impact Of Delay Due To Coupling Capacitance In VSLI Circuits

University of Minnesota M.S.E.E. thesis.May 2019. Major: Electrical/Computer Engineering. Advisor: Sachin Sapatnekar. 1 computer file (PDF); vii, 54 pages.Coupling capacitance is becoming increasingly problematic at the more advanced technology nodes and affects the timing and sign-off timeline of integrated circuits (ICs). As the coupling capacitance information is only available after the detailed routing phase, it can be a difficult task to make any major changes post detailed routing towards fixing issues caused by coupling effects that were unaccounted for. The goal of the project is to come up with an estimate of coupling capacitance for a given net before the detailed routing phase with the help of congestion maps. This information can be fed back to the detailed router which can help avoid routes that are susceptible to heavy coupling effects. The first part of this thesis explains why beforehand knowledge of a net’s coupling capacitance is crucial for a timely tape-out. This thesis revisits the Elmore delay model and extends the analysis to coupled RC structures. The notion of considering the coupling capacitance as a random variable is described to model the uncertainties that are introduced into the delay analysis which is performed ahead in time. The second part of this thesis illustrates how congestion analysis can provide valuable information about the severity of coupling effects. A method for the expedited extraction of estimated parasitics using congestion maps and global router solutions is presented. Modification to existing driving-point analysis techniques is suggested to accommodate coupled RC structures with probabilistic coupling capacitance. The last part of this thesis compares the delay metrics obtained from an open-source timing analyzer with the delay metrics obtained through methods described in this thesis for a given net

Simulation algorithms for inductive effects

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 105-110).by Yehia Mahmoud Massoud.Ph.D

Multilayer Modeling and Design of Energy Managed Microsystems

Aggressive energy reduction is one of the key technological challenges that all segments of the semiconductor industry have encountered in the past few years. In addition, the notion of environmental awareness and designing “green” products is yet another major driver for ultra low energy design of electronic systems. Energy management is one of the unique solutions that can address the simultaneous requirements of high-performance, (ultra) low energy and greenness in many classes of computing systems; including high-performance, embedded and wireless. These considerations motivate the focus of this dissertation on the energy efficiency improvement of Energy Managed Microsystems (EMM or EM2). The aim is to maximize the energy efficiency and/or the operational lifetime of these systems. In this thesis we propose solutions that are applicable to many classes of computing systems including high-performance and mobile computing systems. These solutions contribute to make such technologies “greener”. The proposed solutions are multilayer, since they belong to, and may be applicable to, multiple design abstraction layers. The proposed solutions are orthogonal to each other, and if deployed simultaneously in a vertical system integration approach, when possible, the net benefit may be as large as the multiplication of the individual benefits. At high-level, this thesis initially focuses on the modeling and design of interconnections for EM2. For this purpose, a design flow has been proposed for interconnections in EM2. This flow allows designing interconnects with minimum energy requirements that meet all the considered performance objectives, in all specified system operating states. Later, models for energy performance estimation of EM2 are proposed. By energy performance, we refer to the improvements of energy savings of the computing platforms, obtained when some enhancements are applied to those platforms. These models are based on the components of the application profile. The adopted method is inspired by Amdahl’s law, which is driven by the fact that ‘energy’ is ‘additive’, as ‘time’ is ‘additive’. These models can be used for the design space exploration of EM2. The proposed models are high-level and therefore they are easy to use and show fair accuracy, 9.1% error on average, when compared to the results of the implemented benchmarks. Finally, models to estimate energy consumption of EM2 according to their “activity” are proposed. By “activity” we mean the rate at which EM2 perform a set of predefined application functions. Good estimations of energy requirements are very useful when designing and managing the EM2 activity, in order to extend their battery lifetime. The study of the proposed models on some Wireless Sensor Network (WSN) application benchmark confirms a fair accuracy for the energy estimation models, 3% error on average on the considered benchmarks

Interconnect modeling and optimization in deep sub-micron technologies

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references.Interconnect will be a major bottleneck for deep sub-micron technologies in the years to come. This dissertation addresses the communication aspect from a power consumption and transmission speed perspective. A model for the energy consumption associated with data transmission through deep sub-micron technology buses is derived. The capacitive and inductive coupling between the bus lines as well as the distributed nature of the wires is taken into account. The model is used to estimate the power consumption of the bus as a function of the Transition Activity Matrix, a quantity generalizing the transition activity factors of the individual lines. An information theoretic framework has been developed to study the relation between speed (number of operations per time unit) and energy consumption per operation in the case of synchronous digital systems. The theory provides us with the fundamental minimum energy per input information bit that is required to process or communicate information at a certain rate. The minimum energy is a function of the information rate, and it is, in theory, asymptotically achievable using coding. This energy-information theory combined with the bus energy model result in the derivation of the fundamental performance limits of coding for low power in deep sub-micron buses. Although linear, block linear and differential coding schemes are favorable candidates for error correction, it is shown that they only increase power consumption in buses. Their resulting power consumption is related to structural properties of their generator matrices. In some cases the power is calculated exactly and in other cases bounds are derived.(cont.) Both provide intuition about how to re-structure a given linear (block linear, etc.) code so that the energy is minimized within the set of all equivalent codes. A large class of nonlinear coding schemes is examined that leads to significant power reduction. This class contains all encoding schemes that have the form of connected Finite State Machines. The deep sub-micron bus energy model is used to evaluate their power reduction properties. Mathematical analysis of this class of coding schemes has led to the derivation of two coding optimization algorithms. Both algorithms derive efficient coding schemes taking into account statistical properties of the data and the particular structure of the bus. This coding design approach is generally applicable to any discrete channel with transition costs. For power reduction, a charge recycling technique appropriate for deep sub-micron buses is developed. A detailed mathematical analysis provides the theoretical limits of power reduction. It is shown that for large buses power can be reduced by a factor of two. An efficient modular circuit implementation is presented that demonstrates the practicality of the technique and its significant net power reduction. Coding for speed on the bus is introduced. This novel idea is based on the fact that coupling between the lines in a deep sub-micron bus implies that different transitions require different amounts of time to complete. By allowing only "fast" transitions to take place, we can increase the clock frequency of the bus. The combinatorial capacity of such a constrained bus ...by Paul Peter P. Sotiriadis.Ph.D

Fast Repeater Tree Construction

Repeaters are used during physical design of chips to improve the electrical and timing properties of interconnections. They are added along Steiner trees that connect root gates to sinks, creating repeater trees. Their construction became a crucial part of chip design. We present a new algorithm to solve the repeater tree construction problem. We first present an extensive version of the Repeater Tree Problem. Our problem formulation encapsulates most of the constraints that have been studied so far. We also consider several aspects for the first time, for example, slew dependent required arrival times at repeater tree sinks. The employed technology, the properties of available repeaters and metal wires, the shape of the chip, the temperature, the voltages, and many other factors highly influence the results of repeater tree construction. To take all this into account, we extensively preprocess the environment to extract parameters for our algorithms. We first present an algorithm for Steiner tree creation and prove that our algorithm is able to create timing-efficient as well as cost-efficient trees. Our algorithm is based on a delay model that accurately describes the timing that one can achieve after repeater insertion upfront. Next, we deal with the problem of adding repeaters to a given Steiner tree. The predominantly used algorithms to solve this problem use dynamic programming. However, they have several drawbacks. Firstly, potential repeater positions along the Steiner tree have to be chosen upfront. Secondly, the algorithms strictly follow the given Steiner tree and miss optimization opportunities. Finally, dynamic programming causes high running times. We present our new buffer insertion algorithm, Fast Buffering, that overcomes these limitations. It is able to produce results with similar quality to a dynamic programming approach but a much better running time. In addition, we also present improvements to the dynamic programming approach that allows us to push the quality at the expense of a high running time. We have implemented our algorithms as part of the BonnTools physical design optimization suite developed at the Research Institute for Discrete Mathematics in cooperation with IBM. Our implementation deals with all tedious details of a grown real-world chip optimization environment. We have created extensive experimental results on challenging real-world test cases provided by our cooperation partner. Our algorithm can solve about 5.7 million instances per hour

“We're not dead yet!“: extreme energy and transport poverty, perpetual peripheralization, and spatial justice among Gypsies and Travellers in Northern Ireland

Even though a place to call home may be a fundamental human right, Gypsies and Travellers often confront some of the poorest health outcomes of any group in society, face almost constant accommodation insecurity, and reside in living environments with very poor conditions or high levels of social intolerance. Based on extensive original research with Gypsies and Travellers in Northern Ireland, this study explores their housing and energy needs, transport and mobility patterns, and challenges to their overall health and quality of life. Our investigation revolves around three core thematic areas. In exploring the theme of extreme and recurring poverty and vulnerability, we reveal not only problems but coping strategies and patterns of community resilience. In exploring the theme of perpetual peripheralization, we reveal troubling patterns of intolerance, discrimination, and cultural antagonism. In exploring our theme of spatial justice, we discuss mechanisms to improve the quality of life and energy and mobility outcomes for this marginalised group

A study to evaluate the effectiveness of deep breathing exercise on hot flushes among menopausal wom selected community at Madurai

A quasi experimental study to evaluate the effectiveness of deep breathing exercises on hot flushes among menopausal women in selected community at Madurai district was undertaken by K.RoselinVasanthaKumari, as a partial fulfillment of the requirement of M.Sc (Nursing) under the Dr.M.G.R. Medical University in the year 2012. Objectives of the study were 1. To assess the pretest level of hot flushes among menopausal women in both experimental group and control group. 2. To assess the posttest level of hot flushes among menopausal women in both experimental group and control group. 3. To find the difference between pre and post level of hot flushes among menopausal women in both experimental group and control group. 4. To find the association between pretest level of hot flushes in experimental group with their selected demographic variables among menopausal women. Research hypothesis was formulated as follows: H1There will be significant difference in the hot flushes among experimental and control group of menopausal women after implementation of deep breathing exercise. H2There will be significant association between pre test level of hot flushes and with demographic variables of experimental group. The review of literature was done and organized based on review related to treatment of menopausal symptoms and effectiveness of deep breathing exercise on hot flushes women. The conceptual frame work of this study was based on Wiedenbach’s clinical nursing art theory (1960). The research design used for the study was quasi experimental in nature. A purposive sampling technique was used to collect the data from the study participants. The tool was validated for content and the reliability score was found to be reliable(r= 0.9).The pilot study was conducted in pasumalai, with 6 menopausal women with hot flushes. The main study was conducted at kaithari nagar in Madurai with 60 samples, 30 samples were in control and 30 in experimental group. The data was collected by using hot flush assessment 5 point likert scale. The collected data was analyzed, using descriptive and inferential statistics.Results revealed that hot flush during pretest, most of women 20(67%) were severe hot flushes in experimental group, 16(53%) were moderate symptoms in control group. In the post test, half of the women 15(50%) had moderate hot flush in experimental group, majority of women 24(80%) had moderate in control group. The post test mean score 30.57(3.54) was lower than the pre test mean score 70.67(8.89), the‘t’ value 24.31which was highly significant at 0.001 level in the experimental group. The mean post test score of hot flush in the experimental group 30.57(3.54)was significantly lower than the mean post test scores of hot flush in the control group 62.13(4.46). The findings showed that the deep breathing exercise was effective in reducing hot flush symptoms. There was no significant association between levels of hot flush and selected demographic variables such age, marital status, education, occupation, monthly income of the family.It is inferred that that the menopausal women had reduced severity of hot flush symptoms. It is recommended to do the similar study among urban menopausal women. Implications were recommended in nursing education, nursing practice, nursing administration and nursing research

A Brief Rational Disputation Exercise Enhances Cardiovascular, Anxiety, and Affective Recovery Following Worry-Recall

Rational Emotive Behavior Therapy (REBT) (Ellis, 1958), educates a client on the relationship between one’s irrational beliefs (IBs) and the dysfunctional emotional/behavioral consequences of maintaining those beliefs such as symptoms of anxiety, depression, and sleep dysfunction (Ellis, Gordan, Neenan, & Palmer, 1997), symptoms also commonly correlated with high trait perseverative cognition (PC; Verkuil, Brosschot, de Beurs, & Thayer, 2009). In addition to symptoms of anxiety and depression, high levels of PC, a construct comprised of measures of trait worry and rumination, have been linked to acute cardiovascular (CV) health concerns that overtime when left unmitigated may lead to chronic conditions like hypertension (Ottaviani et al., 2016). Therefore, this study aimed to determine if a brief REBT-based rational disputation exercise was beneficial for those with high PC as evidenced by acute CV, anxiety, and affective recovery to an in-lab worry-recall task. 28 undergraduate students from a midsized urban university were recruited for an in-lab study and randomly assigned to one of two groups; the experimental group utilized a brief rational disputation exercise following worry-recall and the control group sat quietly. Blood pressure (BP), heart rate (HR), affect, and state anxiety were measured throughout the length of the visit. Those in the experimental group experienced significant decreases in SBP, DBP, and HR when asked to think about their new, rational belief and the potential emotional/behavioral benefits of that new belief compared to their SBP, DBP, and HR following the rational disputation exercise. The experimental group had significantly more positive affect, less negative affect compared to the control group at the end of the study. Both groups recovered in levels of state anxiety at the end of the study compared to baseline/pre-study measures. Implications for these findings may include helping those with risky PC profiles more effectively cope with high worry and rumination via brief rational disputation training