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SPICE OPUS pro 2.1SPICE OPUS is a circuit simulator with optimisation utilities. It is a recompilation of the original Berkeley's source code for Windows 95/98/NT and Linux operating systems. Georgia Tech Research Institute's XSPICE mixed-mode simulator was added to the Berkeley code. The XSPICE code model feature was enhanced so that code models can be loaded from dll/so files (.cm files). The simulator includes an interpreted programming language called Nutmeg, which allows interactive SPICE sessions. Numerous memory leaks were fixed. The graphical part of the program was rewritten but the original syntax of the plot and iplot commands was preserved, enabling any script compatibility with other SPICE compilations. We are constantly updating SPICE OPUS with new semiconductor models and we are working very hard to make it as stable as possible.All the above however is just the foundation for our actual research work. We are interested in professional applications of different optimization methods in circuit simulation. Unfortunately there is a host of small memory leaks in any "blood relative" of Berkeley's SPICE, which are usually harmless since the operating system always reclaims allocated memory after an application closes. Serious optimization however needs hundred thousands of continuous simulation runs without choking the memory management system. Therefore we had to develop a very stable simulator before we could even think of optimization. Our main scientific input to SPICE OPUS is an optimization tool including ten different optimization approaches. The user can choose between steepest descent, Newton's method, Davidon-Fletcher-Powell's method, random search, grid search, search along coordinate axes, Powell's method, Hooke-Jeeves's method, constrained simplex, simple genetic algorithm and evaluation of cost function across whole parameter space. Each method has its own set of parameters and they can be combined via NUTMEG scripts. |
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