6,406 research outputs found

    Statistical Power Supply Dynamic Noise Prediction in Hierarchical Power Grid and Package Networks

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    One of the most crucial high performance systems-on-chip design challenge is to front their power supply noise sufferance due to high frequencies, huge number of functional blocks and technology scaling down. Marking a difference from traditional post physical-design static voltage drop analysis, /a priori dynamic voltage drop/evaluation is the focus of this work. It takes into account transient currents and on-chip and package /RLC/ parasitics while exploring the power grid design solution space: Design countermeasures can be thus early defined and long post physical-design verification cycles can be shortened. As shown by an extensive set of results, a carefully extracted and modular grid library assures realistic evaluation of parasitics impact on noise and facilitates the power network construction; furthermore statistical analysis guarantees a correct current envelope evaluation and Spice simulations endorse reliable result

    Automated Netlist Generation for 3D Electrothermal and Electromagnetic Field Problems

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    We present a method for the automatic generation of netlists describing general three-dimensional electrothermal and electromagnetic field problems. Using a pair of structured orthogonal grids as spatial discretisation, a one-to-one correspondence between grid objects and circuit elements is obtained by employing the finite integration technique. The resulting circuit can then be solved with any standard available circuit simulator, alleviating the need for the implementation of a custom time integrator. Additionally, the approach straightforwardly allows for field-circuit coupling simulations by appropriately stamping the circuit description of lumped devices. As the computational domain in wave propagation problems must be finite, stamps representing absorbing boundary conditions are developed as well. Representative numerical examples are used to validate the approach. The results obtained by circuit simulation on the generated netlists are compared with appropriate reference solutions.Comment: This is a pre-print of an article published in the Journal of Computational Electronics. The final authenticated version is available online at: https://dx.doi.org/10.1007/s10825-019-01368-6. All numerical results can be reproduced by the Matlab code openly available at https://github.com/tc88/ANTHE

    Thermal and Electrical Parasitic Modeling for Multi-Chip Power Module Layout Synthesis

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    This thesis presents thermal and electrical parasitic modeling approaches for layout synthesis of Multi-Chip Power Modules (MCPMs). MCPMs integrate power semiconductor devices and drive electronics into a single package. As the switching frequency of power devices increases, the size of the passive components are greatly reduced leading to gains in efficiency and cost reduction. In order to increase switching frequency, electrical parasitics in MCPMs need to be reduced through tighter electronic integrations and smaller packages. As package size is decreased, temperature increases due to less heat dissipation capability. Thus, it is crucial to consider both thermal and electrical parasitics in order to avoid premature device failure. Traditionally, the evaluation of the temperature and electrical parasitics of an MCPM requires the layout to be changed iteratively by hand and verified via finite element analysis (FEA) tools. The novel thermal and electrical parasitics models developed in this thesis predict temperature and electrical parasitics of an MCPM according to varied layouts. Multi-Objective optimization methods are applied to the models to find optimal layouts and tradeoffs of MCPM layouts

    New Cdc Design Tool For Analog Layout Workflow

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    The placement and routing on CMOS analog layout design had always been a time consuming and irritating process due to large amount of transistor devices placements, arrangements and a lot of critical nets routing constraint. Manual efforts to complete analog layout design took few weeks to months’ time in previous project cycle according to the complexity of the circuit. In the meantime, designer needs to convert the devices from schematic into layout in canvas of layout editor, and then arrange the devices accordingly one by one or group by group by moving the devices in order to complete device placement. While for routing, even though there are different auto-routers in existing layout editing tool, but these routers are mostly developed for digital design and unable to route analog signals precisely especially when there are constraints for the routing like matching and shielding. This research presents a new automation solution, Cartoon Diagram Compiler (CDC) tool that enabling a significant productivity improvement on analog layout design. The automation tool provides capability to drag-and-drop the transistor devices/instance cells from schematics canvas to floor planning canvas and is able to auto-place non-critical cells and devices in a virtual mode before converting into real layout. After the floorplan/placement fulfill the design requirement, topologies generator can be used for quick preview of routing option and auto-router support for constrained (shield critical net) and un-constrained nets routing. The area and routing quality nearly matched with hand-drawn layout. The CDC tool has been compare and evaluated on Intel in-house analog layout design projects. In research evaluation, the average time to complete manual device placement and layout routing required 640 minutes and 554 minutes respectively. With device placement and layout routing process only required 139 minutes and 112 minutes or significant reduction in period of about 5.14x and 6.31x respectively. In conclusion, CDC tool increases the productivity by allowing fully automatic derivation of placement and routing, incremental design updates and smart placement guaranteeing design rule free from violation

    On the suitability and development of layout templates for analog layout reuse and layout-aware synthesis

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    Accelerating the synthesis of increasingly complex analog integrated circuits is key to bridge the widening gap between what we can integrate and what we can design while meeting ever-tightening time-to-market constraints. It is a well-known fact in the semiconductor industry that such goal can only be attained by means of adequate CAD methodologies, techniques, and accompanying tools. This is particularly important in analog physical synthesis (a.k.a. layout generation), where large sensitivities of the circuit performances to the many subtle details of layout implementation (device matching, loading and coupling effects, reliability, and area features are of utmost importance to analog designers), render complete automation a truly challenging task. To approach the problem, two directions have been traditionally considered, knowledge-based and optimization-based, both with their own pros and cons. Besides, recently reported solutions oriented to speed up the overall design flow by means of reuse-based practices or by cutting off time-consuming, error-prone spins between electrical and layout synthesis (a technique known as layout-aware synthesis), rely on a outstandingly rapid yet efficient layout generation method. This paper analyses the suitability of procedural layout generation based on templates (a knowledge-based approach) by examining the requirements that both layout reuse and layout-aware solutions impose, and how layout templates face them. The ability to capture the know-how of experienced layout designers and the turnaround times for layout instancing are considered main comparative aspects in relation to other layout generation approaches. A discussion on the benefit-cost trade-off of using layout templates is also included. In addition to this analysis, the paper delves deeper into systematic techniques to develop fully reusable layout templates for analog circuits, either for a change of the circuit sizing (i.e., layout retargeting) or a change of the fabrication process (i.e., layout migration). Several examples implemented with the Cadence's Virtuoso tool suite are provided as demonstration of the paper's contributions.Ministerio de Educación y Ciencia TEC2004-0175

    InSb charge coupled infrared imaging device: The 20 element linear imager

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    The design and fabrication of the 8585 InSb charge coupled infrared imaging device (CCIRID) chip are reported. The InSb material characteristics are described along with mask and process modifications. Test results for the 2- and 20-element CCIRID's are discussed, including gate oxide characteristics, charge transfer efficiency, optical mode of operation, and development of the surface potential diagram

    Modelling and analysis of crosstalk in scaled CMOS interconnects

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    The development of a general coupled RLC interconnect model for simulating scaled bus structures m VLSI is presented. Several different methods for extracting submicron resistance, inductance and capacitance parameters are documented. Realistic scaling dimensions for deep submicron design rules are derived and used within the model. Deep submicron HSPICE device models are derived through the use of constant-voltage scaling theory on existing 0.75µm and 1.0µm models to create accurate interconnect bus drivers. This complete model is then used to analyse crosstalk noise and delay effects on multiple scaling levels to determine the dependence of crosstalk on scaling level. Using this data, layout techniques and processing methods are suggested to reduce crosstalk in system

    Modeling and Analysis of Noise and Interconnects for On-Chip Communication Link Design

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    This thesis considers modeling and analysis of noise and interconnects in onchip communication. Besides transistor count and speed, the capabilities of a modern design are often limited by on-chip communication links. These links typically consist of multiple interconnects that run parallel to each other for long distances between functional or memory blocks. Due to the scaling of technology, the interconnects have considerable electrical parasitics that affect their performance, power dissipation and signal integrity. Furthermore, because of electromagnetic coupling, the interconnects in the link need to be considered as an interacting group instead of as isolated signal paths. There is a need for accurate and computationally effective models in the early stages of the chip design process to assess or optimize issues affecting these interconnects. For this purpose, a set of analytical models is developed for on-chip data links in this thesis. First, a model is proposed for modeling crosstalk and intersymbol interference. The model takes into account the effects of inductance, initial states and bit sequences. Intersymbol interference is shown to affect crosstalk voltage and propagation delay depending on bus throughput and the amount of inductance. Next, a model is proposed for the switching current of a coupled bus. The model is combined with an existing model to evaluate power supply noise. The model is then applied to reduce both functional crosstalk and power supply noise caused by a bus as a trade-off with time. The proposed reduction method is shown to be effective in reducing long-range crosstalk noise. The effects of process variation on encoded signaling are then modeled. In encoded signaling, the input signals to a bus are encoded using additional signaling circuitry. The proposed model includes variation in both the signaling circuitry and in the wires to calculate the total delay variation of a bus. The model is applied to study level-encoded dual-rail and 1-of-4 signaling. In addition to regular voltage-mode and encoded voltage-mode signaling, current-mode signaling is a promising technique for global communication. A model for energy dissipation in RLC current-mode signaling is proposed in the thesis. The energy is derived separately for the driver, wire and receiver termination.Siirretty Doriast
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