A 2-ps Resolution Wide Range BIST Circuit for Jitter Measurement
ABSTRACT In this paper, we propose a novel built-in self-test (BIST) circuit to directly measure cycle-to-cycle jitter. The clock-under-test is under-sampled by this measurement circuit and the jitter values are transformed into digital words. A time-amplified technique is applied to obtain relatively higher resolution with smaller hardware overhead. Experimental results show that our proposed circuit is able to measure the jitter providing the clock frequency up to 2 GHz with resolution of 2 picoseconds.
Conference Paper: Experimental Results of Built-In Jitter Measurement for Gigahertz Clock[Show abstract] [Hide abstract]
ABSTRACT: This paper demonstrates a built-in jitter measurement (BIJM) circuit for Gigahertz clock. Based on a jitter-amplified technique with a pulse-removing mechanism, the pico-second level resolution is achieved in wide frequency range. The experimental results show the feasibility of the proposed BIJM circuit.Asian Test Symposium, 2008. ATS '08. 17th; 12/2008
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ABSTRACT: Abstract When simulating fluids, tetrahedral methods provide flexibility and ease of adaptivity that Cartesian grids find difficult to match. However, this approach has so far been limited by two conflicting requirements. First, accurate simulation requires quality Delaunay meshes and the use of circumcentric pressures. Second, meshes must align with potentially complex moving surfaces and boundaries, necessitating continuous remeshing. Unfortunately, sacrificing mesh quality in favour of speed yields inaccurate velocities and simulation artifacts. We describe how to eliminate the boundary-matching constraint by adapting recent embedded boundary techniques to tetrahedra, so that neither air nor solid boundaries need to align with mesh geometry. This enables the use of high quality, arbitrarily graded, non-conforming Delaunay meshes, which are simpler and faster to generate. Temporal coherence can also be exploited by reusing meshes over adjacent timesteps to further reduce meshing costs. Lastly, our free surface boundary condition eliminates the spurious currents that previous methods exhibited for slow or static scenarios. We provide several examples demonstrating that our efficient tetrahedral embedded boundary method can substantially increase the flexibility and accuracy of adaptive Eulerian fluid simulation.Computer Graphics Forum 05/2010; 29(2):695-704. DOI:10.1111/j.1467-8659.2009.01639.x · 1.60 Impact Factor
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ABSTRACT: We present a multigrid method for solving the linear complementarity problem (LCP) resulting from discretizing the Poisson equation subject to separating solid boundary conditions in an Eulerian liquid simulation’s pressure projection step. The method requires only a few small changes to a multigrid solver for linear systems. Our generalized solver is fast enough to handle 3D liquid simulations with separating boundary conditions in practical domain sizes. Previous methods could only handle relatively small 2D domains in reasonable time, because they used expensive quadratic programming (QP) solvers. We demonstrate our technique in several practical scenarios, including nonaxis-aligned containers and moving solids in which the omission of separating boundary conditions results in disturbing artifacts of liquid sticking to solids. Our measurements show, that the convergence rate of our LCP solver is close to that of a standard multigrid solver.03/2012; 18(8):1191-201. DOI:10.1109/TVCG.2012.86