Mixed-signal analog-digital circuits design on the pre-diffused digital array using trapezoidal association of transistors

The mixed-signal and analog design on a pre-diffused array is a challenging task, given that the digital array is a linear matrix arrangement of minimum-length transistors. To surmount this drawback a specific discipline for designing analog circuits over such array is required. An important novel technique proposed is the use of TAT (Trapezoidal Associations of Transistors) composite transistors on the semi-custom Sea-Of-Transistors (SOT) array. The analysis and advantages of TAT arrangement are extensively analyzed and demonstrated, with simulation and measurement comparisons to equivalent single transistors. Basic analog cells were also designed as well in full-custom and TAT versions in 1.0mm and 0.5mm digital CMOS technologies. Most of the circuits were prototyped in full-custom and TAT-based on pre-diffused SOT arrays. An innovative demonstration of the TAT technique is shown with the design and implementation of a mixed-signal analog system, i. e., a fully differential 2nd order Sigma-Delta Analog-to-Digital (A/D) modulator, fabricated in both full-custom and SOT array methodologies in 0.5mm CMOS technology from MOSIS foundry. Three test-chips were designed and fabricated in 0.5mm. Two of them are IC chips containing the full-custom and SOT array versions of a 2nd-Order Sigma-Delta A/D modulator. The third IC contains a transistors-structure (TAT and single) and analog cells placed side-by-side, block components (Comparator and Folded-cascode OTA) of the Sigma-Delta modulator.

A petri net based timing model for hardware/software co-design of digital systems

We have recently proposed an extension to Petri nets in order to be able to directly deal with all aspects of embedded digital systems. This extension is meant to be used as an internal model of our co-design environment. After analyzing relevant related work, and presenting a short introduction to our extension as a background material, we describe the details of the timing model we use in our approach, which is mainly based in Merlin's time model. We conclude the paper by discussing an example of its usage. © 2004 IEEE.

Digital system design process automation using place/transition petri nets

The constant increase in digital systems complexity definitely demands the automation of the corresponding synthesis process. This paper presents a computational environment designed to produce both software and hardware implementations of a system. The tool for code generation has been named ACG8051. As for the hardware synthesis there has been produced a larger environment consisting of four programs, namely: PIPE2TAB, AGPS, TABELA, and TAB2VHDL. ACG8051 and PIPE2TAB use place/transition net descriptions from PIPE as inputs. ACG8051 is aimed at generating assembly code for the 8051 micro-controller. PIPE2TAB produces a tabular version of a Mealy type finite state machine of the system, its output is fed into AGPS that is used for state allocation. The resulting digital system is then input to TABELA, which minimizes control functions and outputs of the digital system. Finally, the output generated by TABELA is fed to TAB2VHDL that produces a VHDL description of the system at the register transfer level. Thus, we present here a set of tools designed to take a high-level description of a digital system, represented by a place/transition net, and produces as output both an assembly code that can be immediately run on an 8051 micro-controller, and a VHDL description that can be used to directly implement the hardware parts either on an FPGA or as an ASIC.

Archives information publishing new design in post-custodial regime: The National Archives Experience Digital Vaults

The uses of Information and Communication Technologies (ICT) and Web environments for creation, treatment and availability of information have supported the emergence of new social-cultural patterns represented by convergences in textual, image and audio languages. This paper describes and analyzes the National Archives Experience Digital Vaults as a digital publishing web environment and as a cultural heritage. It is a complex system - synthesizer of information design options at information setting, provides new aesthetic aspects, but specially enlarges the cognition of the subjects who interact with the environment. It also enlarges the institutional spaces that guard the collective memory beyond its role of keeping the physical patrimony collected there. Digital Vaults lies as a mix of guide and interactive catalogue to be dealt in a ludic way. The publishing design of the information held on the Archives is meant to facilitate access to knowledge. The documents are organized in a dynamic and not chronological way. They are not divided in fonds or distinct categories, but in controlled interaction of documents previously indexed and linked by the software. The software creates information design and view of documental content that can be considered a new paradigm in Information Science and are part of post-custodial regime, independent from physical spaces and institutions. Information professionals must be prepared to understand and work with the paradigmatic changes described and represented by the new hybrid digital environments; hence the importance of this paper. Cyberspace interactivity between user and the content provided by the environment design provide cooperation, collaboration and sharing knowledge actions, all features of networks, transforming culture globally. © 2011 - IOS Press and the authors. All rights reserved.

Archives information publishing new design in post-custodial regime: The National Archives Experience Digital Vaults

The uses of Information and Communication Technologies (ICT) and Web environments for creation, treatment and availability of information have supported the emergence of new social-cultural patterns represented by convergences in textual, image and audio languages. This paper describes and analyzes the National Archives Experience Digital Vaults as a digital publishing web environment and as a cultural heritage. It is a complex system - synthesizer of information design options at information setting, provides new aesthetic aspects, but specially enlarges the cognition of the subjects who interact with the environment. It also enlarges the institutional spaces that guard the collective memory beyond its role of keeping the physical patrimony collected there. Digital Vaults lies as a mix of guide and interactive catalogue to be dealt in a ludic way. The publishing design of the information held on the Archives is meant to facilitate access to knowledge. The documents are organized in a dynamic and not chronological way. They are not divided in fonds or distinct categories, but in controlled interaction of documents previously indexed and linked by the software. The software creates information design and view of documental content that can be considered a new paradigm in Information Science and are part of post-custodial regime, independent from physical spaces and institutions. Information professionals must be prepared to understand and work with the paradigmatic changes described and represented by the new hybrid digital environments; hence the importance of this paper. Cyberspace interactivity between user and the content provided by the environment design provide cooperation, collaboration and sharing knowledge actions, all features of networks, transforming culture globally.

Properties of individual YBCO layers in a two-layered design for energy-efficient digital data cables

We are developing two-layered Yttrium Barium Copper Oxide (YBCO) thin film structures for energy efficient data links for superconducting electronics and present the results of their property measurements. High temperature superconductors (HTS) are advantageous for the implementation of energy-efficient cables interconnecting low temperature superconductor-based circuits and other cryogenic electronics circuits at higher temperature stages. The advantages of the HTS cables come from their low loss and low dispersion properties, allowing ballistic transfer of low power signals with very high bandwidth, low heat conduction and negligible inter-line crosstalk. The microstrip line cable geometry for typical materials is a two-layered film, in which the two superconducting layers are separated by an insulation layer with a minimized permittivity. We have made a proof of concept design of two YBCO films grown by pulsed laser deposition and then assembled into a sandwich with uniform insulating interlayer of tens of micrometers thick. We report on results obtained from such systems assembled in different ways. Structural and electromagnetic properties have been examined on individual films and on the corresponding sandwich composite. © 2013 IEEE.

Televisão digital interativa: alternativa de design e usabilidade para o aplicativo som e prosa

Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC

Projeto, processo e produto: cartografia do design de conexões na televisão digital

Pós-graduação em Televisão Digital: Informação e Conhecimento - FAAC