Accurate a priori signal integrity estimation using a multilevel dynamic interconnect model for deep submicron VLSI design.

A multilevel dynamic interconnect model was derived for accurate a priori signal integrity estimates. Cross-talk and delay estimations over interconnects in deep submicron technology were analyzed systematically using this model. Good accuracy and excellent time-efficiency were found compared with electromagnetic simulations. We aim to build a dynamic interconnect library with this model to facilitate the interconnect issues for future VLSI design

The impact of design techniques in the reduction of power consumption of SoCs Multimedia

Orientador: Guido Costa Souza de AraújoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: A indústria de semicondutores sempre enfrentou fortes demandas em resolver problema de dissipação de calor e reduzir o consumo de energia em dispositivos. Esta tendência tem sido intensificada nos últimos anos com o movimento de sustentabilidade ambiental. A concepção correta de um sistema eletrônico de baixo consumo de energia é um problema de vários níveis de complexidade e exige estratégias sistemáticas na sua construção. Fora disso, a adoção de qualquer técnica de redução de energia sempre está vinculada com objetivos especiais e provoca alguns impactos no projeto. Apesar dos projetistas conheçam bem os impactos de forma qualitativa, as detalhes quantitativas ainda são incógnitas ou apenas mantidas dentro do 'know-how' das empresas. Neste trabalho, de acordo com resultados experimentais baseado num plataforma de SoC1 industrial, tentamos quantificar os impactos derivados do uso de técnicas de redução de consumo de energia. Nos concentramos em relacionar o fator de redução de energia de cada técnica aos impactos em termo de área, desempenho, esforço de implementação e verificação. Na ausência desse tipo de dados, que relacionam o esforço de engenharia com as metas de consumo de energia, incertezas e atrasos serão frequentes no cronograma de projeto. Esperamos que este tipo de orientações possam ajudar/guiar os arquitetos de projeto em selecionar as técnicas adequadas para reduzir o consumo de energia dentro do alcance de orçamento e cronograma de projetoAbstract: The semiconductor industry has always faced strong demands to solve the problem of heat dissipation and reduce the power consumption in electronic devices. This trend has been increased in recent years with the action of environmental sustainability. The correct conception of an electronic system for low power consumption is an issue with multiple levels of complexities and requires systematic approaches in its construction. However, the adoption of any technique for reducing the power consumption is always linked with some specific goals and causes some impacts on the project. Although the designers know well that these impacts can affect the design in a quality aspect, the quantitative details are still unkown or just be kept inside the company's know-how. In this work, according to the experimental results based on an industrial SoC2 platform, we try to quantify the impacts of the use of low power techniques. We will relate the power reduction factor of each technique to the impact in terms of area, performance, implementation and verification effort. In the absence of such data, which relates the engineering effort to the goals of power consumption, uncertainties and delays are frequent. We hope that such guidelines can help/guide the project architects in selecting the appropriate techniques to reduce the power consumption within the limit of budget and project scheduleMestradoCiência da ComputaçãoMestre em Ciência da Computaçã

Physics-based equivalent circuit model extraction for system level PDN and a novel PDN impedance measurement method

“The power distribution network (PDN) plays an important role in the power supply system, especially with the increasing of the working frequency of the integrated circuit (IC). A physics-based circuit modeling methodology is proposed in the first section. The circuit model is extracted by following the current path in the system PDN and the related parameters are calculated based on the cavity model and plane-pair PEEC methods. By extracting the equivalent circuit model, the PDN system will be transformed into RLC element-based circuit. The role of each part of the system will be easily explained and the system behavior could be changed by changing the dominance part accordingly. This methodology makes a good contribution to the system level PDN troubleshooting and layout design optimization. Compared with analytical methodologies, the measurement result is more solid and convincing. The special part of PDN is that the impedance could be as low as several milliohms, and the impedance varies during the frequency, so the accuracy of impedance measurement is challenging. Based on all these requirements, a novel PDN low impedance measurement methodology is proposed, and a probe based on I-V method is designed to support this methodology, which provides a new and practical approach of PDN impedance measurement with easy landing, simple setup, lower frequency, and less instrument quality dependent advantages. This probe could work in a wide frequency range with a relatively sufficient dynamic range”--Abstract, page iii

Delay Extraction Based Equivalent Elmore Model For RLC On-Chip Interconnects

As feature sizes for VLSI technology is shrinking, associated with higher operating frequency, signal integrity analysis of on-chip interconnects has become a real challenge for circuit designers. For this purpose, computer-aided-design (CAD) tools are necessary to simulate signal propagation of on-chip interconnects which has been an active area for research. Although SPICE models exist which can accurately predict signal degradation of interconnects, they are computationally expensive. As a result, more effective and analytic models for interconnects are required to capture the response at the output of high speed VLSI circuits. This thesis contributes to the development of efficient and closed form solution models for signal integrity analysis of on-chip interconnects. The proposed model uses a delay extraction algorithm to improve the accuracy of two-pole Elmore based models used in the analysis of on-chip distributed RLC interconnects. In the proposed scheme, the time of fight signal delay is extracted without increasing the number of poles or affecting the stability of the transfer function. This algorithm is used for both unit step and ramp inputs. From the delay rational approximation of the transfer function, analytic fitted expressions are obtained for the 50% delay and rise time for unit step input. The proposed algorithm is tested on point to point interconnections and tree structure networks. Numerical examples illustrate improved 50% delay and rise time estimates when compared to traditional Elmore based two-pole models

HIGH PERFORMANCE CLOCK DISTRIBUTION FOR HIGH-SPEED VLSI SYSTEMS

Tohoku University堀口 進課

System level power integrity transient analysis using a physics-based approach

With decreasing supply voltage level and massive demanding current on system chipset, power integrity design becomes more and more critical for system stability. The ultimate goal of well-designed power delivery network (PDN) is to deliver desired voltage level from the source to destination, in other words, to minimize voltage noise delivered to digital devices. The thesis is composed of three parts. The first part focuses on-die level power models including simplified chip power model (CPM) for system level analysis and the worst scenario current profile. The second part of this work introduces the physics-based equivalent circuit model to simplify the passive PDN model to RLC circuit netlist, to be compatible with any spice simulators and tremendously boost simulation speed. Then a novel system/chip level end-to-end transient model is proposed, including the die model and passive PDN model discussed in previous two chapters as well as a SIMPLIS based small signal VRM model. In the last part of the thesis, how to model voltage regulator module (VRM) is explicitly discussed. Different linear approximated VRM modeling approaches have been compared with the SIMPLIS small signal VRM model in both frequency domain and time domain. The comparison provides PI engineers a guideline to choose specific VRM model under specific circumstances. Finally yet importantly, a PDN optimization example was given. Other than previous PDN optimization approaches, a novel hybrid target impedance concept was proposed in this thesis, in order to improve system level PDN optimization process --Abstract, page iv

Noise compliant macromodel synthesis for RF and Mixed-Signal applications

This paper proposes a compact synthesis approach for reduced-order behavioral macromodels of linear circuit blocks for RF and Mixed-Signal design. The proposed approach revitalizes the classical synthesis of lumped linear and timeinvariant multiport networks by reactance extraction, which is here exploited to obtain reduced-order equivalent SPICE netlists that can be used in any type of system-level simulations, including transient and noise analysis. The effectiveness of proposed approach is demonstrated on a real design applicatio

Design and practical realization of polymorphic crosstalk circuits using 65nm TSMC PDK

Title from PDF of title page viewed January 14, 2020Thesis advisor: Mostafizur RahmanVitaIncludes bibliographical references (page 54-56)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City. 2019As the technology node scales down, the coupling capacitance between the adjacent metal lines increases. With an increase in this electrostatic coupling, the unwanted signal interference also increases, which is popularly called as Crosstalk. In conventional circuits, the Crosstalk affects either functionality or performance or both. Therefore the Crosstalk is always considered as detrimental to the circuits, and we always try to filter out the Crosstalk noise from signals. Crosstalk Computing Technology tries to astutely turn this unwanted coupling capacitance into computing principle for digital logic gates[1, 2]. The special feature of the crosstalk circuits is its inherent circuit mechanism to build polymorphic logic gates[3]. Our team has previously demonstrated various fundamental polymorphic logic circuits [1-6,16-18]. This thesis shows the design of the large-scale polymorphic crosstalk circuits such as Multiplier–Sorter, Multiplier–Sorter–Adder using the fundamental polymorphic gates, and also analyzes the Power, Performance, and Area (PPA) for these large-scale designs. Similar to the basic and complex polymorphic gates, the functionality of the large-scale polymorphic circuits can also be altered using the control signals. Owing to their multi-functional embodiment in a single circuit, polymorphic circuits find a myriad of useful applications such as reconfigurable system design, resource sharing, hardware security, and fault-tolerant circuit design, etc. [3]. Also, in this thesis, a lot of studies have been done on the variability (PVT analysis) of Crosstalk Circuits. This PVT variation analysis establishes the circuit design requirements in terms of coupling capacitances and fan-in limitation that allows reliable operation of the Crosstalk gates under Process, Voltage and Temperature variations. As an example, I also elaborate on the reason for which the full adder can’t be implemented as a single gate in the crosstalk circuit-style at lower technology nodes. Though we designed a variety of basic and complex logic gates and crosstalk polymorphic gates, the biggest question is “Will these crosstalk gates work reliably on silicon owing to their new circuit requirements and technological challenges?”. Trying to answer the above question, the whole thesis is mainly focused on the physical implementation of the crosstalk gates at 65nm. I will detail the steps that we have performed while designing the crosstalk circuits and their layouts, the challenges we faced while implementing the new circuit techniques using conventional design approaches and PDK, and their solutions, specifically during layout design and verification. The other potential application of crosstalk circuits is in non-linear analog circuits: Analog-to-Digital Converter (ADC) [4], Digital-to-Analog Converter (DAC), and Comparator. In this thesis, I have shown how the deterministic charge summation principle that is used in digital crosstalk gates can also be used to implement the non-linear analog circuits.Introduction -- Polymorphic Crosstalk circuit design -- Practical realization of Crosstalk circuits -- PVT variation analysis -- Difficulties or errors in layout design and full chip details -- Potential miscellaneous applications -- Conclusion and future wor