Analog IC Design with a Library of Parameterized Device Generators

International audienceThe CAIRO+ tool allows the designer of analog circuits to automate his flow, and permits the reuse. However, it doesn’t prevent him from controlling the generation. CAIRO+ is based on a library of smart generators which can handle the analog specific constraints, related to the electrical synthesis or to the design rules for a reliable layout. Here we present what are these device generators and how they can be used in a complex design automation. The example of a simple OTA using some of the available generators is shown

A simple 3.8mW, 300 MHz, 4-bit flash analog-to-digital converter

International audienceThis paper presents a fully differential comparator that can be used in a N bit Flash A/D converter as continuous-time sigma-delta modulator quantizer. The comparator is an extension of the dynamic comparator presented by Lewis and Gray, resulting in a 4 bit A/D. Its main advantages are : compact architecture based on MOS transistor only, without any passive components such as resistance ladder or switch capacitance, fully differential input and output voltages, operating at very low voltage. Using this comparator, a 4 bit flash A/D converter has been designed in a 0.13μm CMOS technology, under 1.2V supply voltage. It operates at 300Msample/s, suitable for over sampled data converter. The simulation shows a 3.8mW power consumption for the whole ADC

A Layout-Educated Analog Design Flow

International audienceIn this paper, we present a new flow for analog design automation. It is an electrical and layout co-design flow which is based on the precise knowledge of the process electrical models and layout. This flow is as fast as a layout-aware flow since the layout informations aren’t given by an external extractor, but are measured while generating the layout. But it is also as accurate as a layout-inclusive flow seeing that it goes until the layout generation. It is so a layout-educated flow which, by a strong separation from the target process, allows the technology migration for commonly used designs. All the expertise of the proposed flow is contained in the device generators, which are the leaf cells of the flow hierarch

Modeling Heterogeneous Systems Using SystemC-AMS Case Study: A Wireless Sensor Network Node

Abstract — The paper presents a preliminary approach for the modeling and simulation of a simple but complete Wireless Sensor Network with two nodes using SystemC-AMS, an open-source C++ library dedicated to the description of heterogeneous systems containing digital, analog, RF hardware parts as well as embedded software. The WSN node, or mote, detailed herein consists of a physical sensor, a continuous time sigmadelta converter with its associated decimation filter, an ATMEGA128 8-bit microcontroller running the embedded application and a QPSK-based 2.4 GHz RF transceiver. The node has been designed to be interoperable with both the XBow MICAZ hardware platform and the TinyOS operating system in a near future. The paper starts with the structural description of the system as a hierarchical set of behavioural modules, then gives an insight on how multi-frequency simulation is handled in SystemC-AMS, and finally presents simulation results that are systematically compared with the Matlab reference in terms of accuracy and simulation time. I

A Mixed Equation-based and Simulation-based Design Methodology for Continuous-Time Sigma-Delta Modulators

International audienceThis paper presents a design automation tool for continuous-time sigma-delta modulators from high level specifications down to layout. System level synthesis, circuit synthesis as well as layout synthesis are performed in the CAIRO+ design environment. Strong interaction between the system level and the circuit level is used to optimize the final design. The design of a complete third order current-mode continuous-time sigma-delta modulator is taken as an example to show the effectiveness of the proposed design methodology

Automatic Synthesis and Simulation of Continuous-Time Sigma Delta Modulators

International audienceThis paper presents a mixed equation-based and simulation-based design methodology for continuous-time sigma-delta modulators from high level specifications down to layout. The calculation and scaling of the sigma-delta coefficients as well as circuit sizing and layout generation are implemented in the same analog design environment CAIRO+. The design of a complete third order current-mode continuous-time sigma-delta modulator is taken as an example to show the effectiveness of the proposed design methodology

Design Space Exploration for Analog IPs using CAIRO+

International audienceIn this paper, a new methodology for design space exploration (DSE) and knowledge capture is presented. The methodology presents analog IPs as a hierarchy of devices and modules. The hierarchy is implemented using an analog language called CAIRO+. A mechanism, which is established between devices and modules, allows modules to question devices about their electrical behavior. The electrical properties propagate upward along the hierarchy in order to guide higher level modules. This methodology is used to capture and document the designer’s knowledge. Once captured, an executable generator is produced. This generator is then used to synthesize analog IPs with different specifications. The same generator can be used to migrate analog IPs between different technologies. As an illustrative example, a fully-differential two stages common-mode feedback (CMFB) amplifier is synthesized and migrated using CAIRO+

A Language to Design Generators of Analog Functions

International audienceHere we present the CAIRO+ language, based on C++ functions, dedicated to the design of analog function generators. This language is aimed to enable the designer to store his knowledge into a generator. The generator is used to size fixed topologies with different specifications. It can also be used to migrate analog functions between different technologies

Les échelles des territorialités

La mondialisation, faisant apparaître, légitimant ou contribuant à la montée en puissance de territorialités très diverses, devait en toute apparence faire disparaître les frontières et les territoires, rendus obsolètes ou contre-productifs. L’argumentaire est connu, mais il résiste mal à l’examen de diverses situations concrètes. Le territoire persiste ou, mieux, se déploie : il reste l’outil privilégié d’organisation et de contrôle de l’espace. Comment expliquer cet apparent paradoxe autrement qu’en recourant à une prétendue universalité des rapports de l’homme à l’espace ? Les articles de ce numéro spécial montrent, à travers les manières dont le pouvoir pense l’espace en le découpant, ce qu’il y a de culturel et de stratégique dans le territoire. En étudiant les territorialités induites par diverses formes de mondialisation, ces articles montrent en particulier que c’est parce que ces territorialités se structurent, face au pouvoir, à certaines échelles – celles de la modernité politique – que le territoire peut se renouveler constamment

Contrôler les finances sous l’Ancien Régime

Colloque des 28, 29 et 30 novembre 2007 Grâce au regain d’intérêt pour l’histoire institutionnelle et au renouvellement des questionnements sur l’État royal sous l’Ancien Régime, les Chambres des comptes sont enfin sorties de l’ombre. Les actes du colloque tenu à Paris du 28 au 30 novembre 2007, à l’occasion du bicentenaire de la Cour des comptes et du 25e anniversaire des Chambres régionales, présentent la géographie des Chambres des comptes, qu’elles soient royales ou princières, décrivent leurs attributions en matière de contrôle des comptables et de surveillance du domaine royal et se penchent sur des aspects moins connus comme l’administration de la régale temporelle. Cet ouvrage apporte des éclairages sur le personnel des Chambres des comptes, la hiérarchie marquée par un clivage majeur entre les présidents et les maîtres — qui ont seuls la qualité de juge — et les auditeurs et correcteurs, le recrutement social et les dynasties qui y ont vu le jour et donné corps à l’institution. Il replace enfin les Chambres des comptes dans le champ institutionnel en reconstituant les relations — faites de conflits mais aussi d’alliances, parfois surprenantes — qu’elles ont nouées avec d’autres corps comme les États provinciaux ou les Parlements. Supprimées en 1791, les Chambres sont réapparues à l’époque contemporaine : obéissant à d’autres principes, elles n’ont qu’un lointain rapport avec leurs devancières comme le révèle la table ronde qui a réuni à l’issue du colloque plusieurs de leurs magistrats et dont les principaux éléments sont rapportés en fin de volume.Seminar on 28, 29 and 30 November 2007 under the scientific editorship of Dominique Le Page Renewed interest in institutional history and the Royal State under the Old Regime has finally brought the courts of accounts out from the shadows. The proceedings on the seminar held in Paris from 18 to 30 November 2007 to mark the bicentenary of the State Audit Office and the 25th anniversary of the regional audit offices present the geography of both royal and princely audit offices. They describe their accountant auditing and royal estate supervisory responsibilities, and consider lesser known aspects such as the temporal regalia administration. The book sheds light on the courts of accounts’ staff, the hierarchy with its strict division between presiding barons and puisne barons – alone empowered to adjudge – and auditors and examiners, social recruitment, and the dynasties that emerged and shaped the institution. It situates the courts of accounts in the institutional landscape by reconstituting the relations – rife with conflicts, but also sometimes surprising alliances – that they formed with other corps such as the provincial governments and the parliaments. The courts of accounts that were abolished in 1791 have reappeared today in the form of the audit offices. These new audit offices abide by different principles and have changed virtually out of all recognition from their predecessors, as shown by the round table attended by a number of audit offices judges at the end of the seminar, the main elements of which are reported on at the end of the volume.Coloquio celebrado los días 28, 29 y 30 de noviembre de 2007, bajo la dirección científica de Dominique Le Page Gracias a la recuperación del interés por la historia institucional y al renovado cuestionamiento del Estado real bajo el Antiguo Régimen, las Cámaras de cuentas han salido, por fin, de las penumbras. En las actas del coloquio celebrado en París entre el 28 y el 30 de noviembre de 2007 con ocasión del bicentenario del Tribunal de Cuentas francés y el 25º aniversario de las Cámaras regionales, se presentó la geografía de las Cámaras de cuentas (tanto de origen real como principesco), y se describieron sus atribuciones en materia de control de los contables y vigilancia de las posesiones reales, además de abordarse aspectos menos conocidos, como la administración de la regalía temporal. Esta obra aporta nuevas perspectivas sobre el personal de las Cámaras de cuentas, su jerarquía, caracterizada por una marcada división entre los presidentes y maîtres (los únicos que poseen la calidad de juez) y los auditores y correctores, la contratación social y las dinastías que surgieron en el seno de la institución y le dieron forma. Por último, resitúa a las Cámaras de cuentas en el ámbito institucional reconstruyendo las relaciones (conformadas por conflictos, pero también por alianzas, en ocasiones sorprendentes) que establecieron con otros organismos como los Estados provinciales o los Parlamentos. Suprimidas en 1791, las Cámaras volvieron a aparecer en la época contemporánea; actualmente, obedecen a principios diferentes y tan solo guardan una relación lejana con sus predecesoras, como pone de manifiesto la mesa redonda que reunió tras el coloquio a algunos de sus magistrados y cuyos aspectos principales se exponen al final del volumen