Roundtable: Design and CAD Challenges for Leading-Edge Multimedia Designs

Multimedia, game, and entertainment devices have pushed the leading edge of performance, complexity, power, form factor, design cycle time, and other key aspects of ASIC design for the past several technology nodes. This roundtable brings together experts who are defining the next generation of gaming, mobile-TV, digital-home, display, and multimedia-processing platforms. The discussion spans the underlying chip architectures and roadmaps, as well as the key design, technology, and market challenges for next-generation products.     

Stochastic Power/Ground Supply Voltage Prediction and Optimization Via Analytical Placement

Increasingly significant power/ground (P/G) supply voltage degradation in nanometer VLSI designs leads to system performance degradation and even malfunction, which requires stochastic analysis and optimization techniques. We represent the supply voltage degradation at a P/G node as a function of the supply currents and the effective resistance of a P/G supply network and propose an efficient stochastic system-level P/G supply voltage prediction method, which computes P/G supply network effective resistances in a random walk process. We further propose to reduce P/G supply voltage degradation via placement of supply current sources, and integrate P/G supply voltage degradation reduction with conventional placement objectives in an analytical placement framework. Our experimental results show that the proposed stochastic P/G supply network prediction method achieves 10x-100x speedup compared with traditional SPICE simulation, and the proposed P/G supply voltage degradation aware placement achieves an average of 20.9% (11.7%) reduction on maximum (average) supply voltage degradation with only 4.3% wirelength increase.     

Does functional communication training compete with ongoing contingencies of reinforcement? An analysis during response acquisition and maintenance

We examined the effectiveness of functional communication training (FCT) in reducing self-injurious behavior (SIB) and in shaping an alternative (communicative) response while SIB continued to be reinforced. Following a functional analysis of 3 individuals' SIB, we attempted to teach an alternative response consisting of a manual sign to each individual, using the reinforcer that maintained SIB. When FCT was implemented without extinction. SIB remained at baseline rates for all participants, and none of the participants acquired the alternative response. When extinction was added to the training procedure, SIB decreased and manual signing increased for all participants. To determine if signing, when established, would compete with SIB when both were reinforced, extinction was then withdrawn. Signing was maintained and SIB occurred at low rates for 2 individuals, but SIB returned to baseline rates for the 3rd individual, necessitating the reimplementation of extinction. These results suggest that it may be difficult to establish alternative behaviors if inappropriate behavior continues to be reinforced, but that, when established, alternative behavior might compete successfully with ongoing contingencies of reinforcement for inappropriate behavior.     

A general framework for vertex orderings with applications tocircuit clustering

Vertex orderings have been successfully applied to problems in netlist clustering and for system partitioning and layout. We present a vertex ordering construction that encompasses most reasonable graph traversals. Two parameters-an attraction function and a window-provide the means for achieving various graph traversals and addressing particular clustering requirements. We then use dynamic programming to optimality split the vertex ordering into a multiway clustering. Our approach outperforms several clustering methods in the literature in terms of three distinct clustering objectives. The ordering construction, by itself, also outperforms existing graph ordering constructions for this application. Tuning our approach to “meta-objectives”, particularly clustering for two-phase Fiduccia-Mattheyses bipartitioning, remains an open area of research     

Cooperative Mobile Robotics: Antecedents and Directions

There has been increased research interest in systems composed of multiple autonomous mobile robots exhibiting cooperative behavior. Groups of mobile robots are constructed, with an aim to studying such issues as group architecture, resource conflict, origin of cooperation, learning, and geometric problems. As yet, few applications of cooperative robotics have been reported, and supporting theory is still in its formative stages. In this paper, we give a critical survey of existing works and discuss open problems in this field, emphasizing the various theoretical issues that arise in the study of cooperative robotics. We describe the intellectual heritages that have guided early research, as well as possible additions to the set of existing motivations.     

Practical Bounded-Skew Clock Routing

In Clock routing research, such practical considerations as hierarchical buffering, rise-time and overshoot constraints, obstacle- and legal location-checking, varying layer parasitics and congestion, and even the underlying design flow are often ignored. This paper explores directions in which traditional formulations can be extended so that the resulting algorithms are more useful in production design environments. Specifically, the following issues are addressed: (i) clock routing for varying layer parasitics with non-zero via parasitics; (ii) obstacle-avoidance clock routing; and (iii) hierarchical buffered tree synthesis. We develop new theoretical analyses and heuristics, and present experimental results that validate our new approaches.     

GA-optimized decoupling capacitors damping the rectangular power-bus' cavity-mode resonances

The genetic algorithm (GA) is suggested to find the decoupling capacitors for suppressing the cavity-mode resonances in the printed circuit board power-bus structure. The optimal positions and circuital values of decoupling capacitors are efficiently determined to selectively mitigate specific resonance peaks. The optimization of the damping is validated with the measurement and develops to multiresonance modes' damping.     

The unique ergodic measure of the symmetric piecewise toral isometry of rotation angle θ=kπ/5 is the Hausdorff measure of its singular set

It is known that the symmetric piecewise toral isometry of rotation angle θ = k π /5, k=1, 2, 3, 4 is uniquely ergodic in 'a certain subset' of its singular set (aka exceptional set). The purpose of this paper is to identify the unique ergodic measure explicitly. In fact, we prove that the unique ergodic measure is none other than the normalized Hausdorff measure of the singular set, consequently proving that the unique ergodicity holds in the entire singular set. We use the 'phantom dynamics' given by a number of symmetry identifications as our main tool.