Configurable multiplier modules for an adaptive computing system

The importance of reconfigurable hardware is increasing steadily. For example, the primary approach of using adaptive systems based on programmable gate arrays and configurable routing resources has gone mainstream and high-performance programmable logic devices are rivaling traditional application-specific hardwired integrated circuits. Also, the idea of moving from the 2-D domain into a 3-D design which stacks several active layers above each other is gaining momentum in research and industry, to cope with the demand for smaller devices with a higher scale of integration. However, optimized arithmetic blocks in course-grain reconfigurable arrays as well as field-programmable architectures still play an important role. In countless digital systems and signal processing applications, the multiplication is one of the critical challenges, where in many cases a trade-off between area usage and data throughput has to be made. But the a priori choice of word-length and number representation can also be replaced by a dynamic choice at run-time, in order to improve flexibility, area efficiency and the level of parallelism in computation. In this contribution, we look at an adaptive computing system called 3-D-SoftChip to point out what parameters are crucial to implement flexible multiplier blocks into optimized elements for accelerated processing. The 3-D-SoftChip architecture uses a novel approach to 3-dimensional integration based on flip-chip bonding with indium bumps. The modular construction, the introduction of interfaces to realize the exchange of intermediate data, and the reconfigurable sign handling approach will be explained, as well as a beneficial way to handle and distribute the numerous required control signals

Comparison of reconfigurable structures for flexible word-length multiplication

Binary multiplication continues to be one of the essential arithmetic operations in digital circuits. Even though field-programmable gate arrays (FPGAs) are becoming more and more powerful these days, the vendors cannot avoid implementing multiplications with high word-lengths using embedded blocks instead of configurable logic. But on the other hand, the circuit's efficiency decreases if the provided word-length of the hard-wired multipliers exceeds the precision requirements of the algorithm mapped into the FPGA. Thus it is beneficial to use multiplier blocks with configurable word-length, optimized for area, speed and power dissipation, e.g. regarding digital signal processing (DSP) applications. <br><br> In this contribution, we present different approaches and structures for the realization of a multiplication with variable precision and perform an objective comparison. This includes one approach based on a modified Baugh and Wooley algorithm and three structures using Booth's arithmetic operand recoding with different array structures. All modules have the option to compute signed two's complement fix-point numbers either as an individual computing unit or interconnected to a superior array. Therefore, a high throughput at low precision through parallelism, or a high precision through concatenation can be achieved

Timing of deformation in the Sarandí del Yí Shear Zone, Uruguay: implications for the amalgamation of western Gondwana during the Neoproterozoic Brasiliano-Pan-African Orogeny

U-Pb and Hf zircon (sensitive high-resolution ion microprobe -SHRIMP- and laser ablation-inductively coupled plasma-mass spectrometry -LA-ICP-MS-), Ar/Ar hornblende and muscovite, and Rb-Sr whole rock-muscovite isochron data from the mylonites of the Sarandí del Yí Shear Zone, Uruguay, were obtained in order to assess the tectonothermal evolution of this crustal-scale structure. Integration of these results with available kinematic, structural, and microstructural data of the shear zone as well as with geochronological data from the adjacent blocks allowed to constrain the onset of deformation along the shear zone at 630-625 Ma during the collision of the Nico Pérez Terrane and the Río de la Plata Craton. The shear zone underwent dextral shearing up to 596 Ma under upper to middle amphibolite facies conditions, which was succeeded by sinistral shearing under lower amphibolite to upper greenschist facies conditions until at least 584 Ma. After emplacement of the Cerro Caperuza granite at 570 Ma, the shear zone underwent only cataclastic deformation between the late Ediacaran and the Cambrian. The Sarandí del Yí Shear Zone is thus related to the syncollisional to postcollisional evolution of the amalgamation of the Río de la Plata Craton and the Nico Pérez Terrane. Furthermore, the obtained data reveal that strain partitioning and localization with time, magmatism emplacement, and fluid circulation are key processes affecting the isotopic systems in mylonitic belts, revealing the complexity in assessing the age of deformation of long-lived shear zone

Interpreting and reporting ⁴⁰Ar/³⁹Ar geochronologic data

The ⁴⁰Ar/³⁹Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth’s formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing ⁴⁰Ar/³⁹Ar dates with analytical uncertainties of ∼0.1%, thereby providing precise time constraints for a wide range of geologic and extraterrestrial processes. Analyses of increasingly smaller subsamples have revealed age dispersion in many materials, including some minerals used as neutron fluence monitors. Accordingly, interpretive strategies are evolving to address observed dispersion in dates from a single sample. Moreover, inferring a geologically meaningful “age” from a measured “date” or set of dates is dependent on the geological problem being addressed and the salient assumptions associated with each set of data. We highlight requirements for collateral information that will better constrain the interpretation of ⁴⁰Ar/³⁹Ar data sets, including those associated with single-crystal fusion analyses, incremental heating experiments, and in situ analyses of microsampled domains. To ensure the utility and viability of published results, we emphasize previous recommendations for reporting ⁴⁰Ar/³⁹Ar data and the related essential metadata, with the amendment that data conform to evolving standards of being findable, accessible, interoperable, and reusable (FAIR) by both humans and computers. Our examples provide guidance for the presentation and interpretation of ⁴⁰Ar/³⁹Ar dates to maximize their interdisciplinary usage, reproducibility, and longevity

Crust-mantle interaction during syn-collisional magmatism – evidence from the Oamikaub diorite and Neikhoes metagabbro (Damara orogen, Namibia)

Highlights • Synorogenic igneous rocks (Damara orogen) give evidence for crust-mantle interaction. • Assimilation of crustal material is widespread and includes lower crustal rocks. • A common subduction zone setting is unlikely. • Flat subduction tectonics may explain the chemical and isotope composition. Abstract The early-syntectonic 563.7±6.1 Ma old Oamikaub diorite (Damara orogen, Namibia) consists of metaluminous, magnesian, calc-alkalic to calcic diorites, granodiorites and granites. Associated gabbro-diorites and gabbros belong to the Neikhoes metagabbro. Linear major and trace element variations imply that the rock suite evolved through fractional crystallization processes involving amphibole, biotite, Fe-Ti oxides, zircon and apatite. Initial Sr (87Sr/86Sr: 0.7058-0.7123) and Nd (ε Nd: -2.1 to -18.8) isotopic compositions are highly variable and negatively correlated indicating that assimilation of crustal components occurred. Unradiogenic initial 206Pb/204Pb (16.23-17.23) and 207Pb/204Pb ratios (15.50-15.57) suggest derivation from or interaction with ancient crust with low U/Pb. Two gabbro-diorites have MgO, Ni and Cr abundances that are compatible with derivation of these rocks from upper mantle lithologies. Their initial ε Nd values (-2.1 and – 7.4) and 87Sr/86Sr ratios (0.7058 and 0.7076) imply derivation from an aged metasomatized lithospheric mantle. Other mafic samples have MgO abundances and compatible element concentrations that exceed the values commonly accepted for primary mafic melts implying some accumulation of clinopyroxene and amphibole. The granodiorites form a homogenous group in which the isotope data (initial ε Nd: -12.4 to -14.1; initial 87Sr/86Sr: 0.7083-0.7096) imply a lower crustal source. The granites are also magnesian and calc-alkaline but two of them are strongly peraluminous. Their isotope data (initial ε Nd: -13.2 to -18.8; initial 87Sr/86Sr: 0.7099 to 0.7123) imply derivation from more ancient sources, alternatively these samples gained their isotope systematics through extensive AFC processes from parental granodiorites. A common subduction zone environment as suggested from negative Nb-Ta anomalies in multi-element diagrams seems unlikely for all samples because of a lack of isotopically depleted signatures. The data from the Oamikaub diorite and other mafic complexes are better explained by a “flat” subduction model involving mainly continental mantle lithosphere and crust with limited, if any, melting of asthenospheric mantle

Contrib. Mineral. Petrol.

We report major-element, trace-element and isotopic data of volcanic rocks from the late-Neoproterozoic (570 Ma) Agardagh Tes-Chem ophiolite in Central Asia. south-west of Lake Baikal (50.5degreesN, 95degreesE). The majority of samples are high- alumina basalts and basaltic andesites having island-are affinities. They were derived from an evolved parental magma (Mg # greater than or equal to 0.60 Crsimilar to180 ppm, Nisimilar to95 ppm) by predominantly clinopyroxene fractionation. The parental magma developed from a primary mantle melt by fractionation of about 12% of an olivine+spinel assemblage. The island-are rocks have high abundances of incompatible trace elements fight rare-earth element abundances up to 100 times chondritic, chondrite-normalised (La/Yb)(n) = 14.6-5.1) and negative Nb anomalies (Nb/La = 0.37-0.62). but low Zr/Nb ratios (7-14). Initial epsilon(Nd) values are around +5.5, initial Pb isotopic compositions are Pb-206/Pb-204 = 17.39-18.45, Pb-207/Pb-204 = 15.49-15.61. Pb-208/Pb-204 = 37.06-38.05. Enrichment of large-ion lithophile elements within this group is significant (Ba/La= 11-130). Another group of samples consists of back-arc basin-related volcanic rocks. They are most likely derived from the same depleted mantle source as the island-arc rocks, but underwent higher degrees of melting (8-15%) and are not influenced by slab components. They have lower abundances of incompatible trace elements, flat rare- earth element patterns [(La/Yb)(n) = 0.6-2.4] and higher epsilon(Nd) values (+7.8 to +8.5). Negative Nb anomalies are absent (Nb/La 0.81-1.30), but Zr/Nb is high (21-48). At least three components are necessary to explain the geochemical evolution of the volcanic rocks: (1) an enriched (ocean island- like) component characterised by a high Nb concentration (up to 30 ppm), an absent negative Nb anomaly, a low Zr/Nb ratio (similar to6.5. a low epsilon(Nd) value (around 0), and radiogenic Pb-206/Pb-204, Pb-207/Pb-204 and Pb-208/Pb-204; (2) a back-arc basin component similar to N-MORB with a flat rare- earth element pattern and a high epsilon(Nd) value (around + 8.5), and (3) an island-arc component from a mantle source which was modified by the downgoing slab. Crystal fractionation superimposed on mixing and source contamination by subducted sediments is suitable to explain the observed geochemical data. The most likely geodynamic environment to produce these characteristics is a young, intra-oceanic island-are system and an associated back-arc basin