VLSICP computes various distributed attributes ranging from potential distributions and electrostatic fields to space charges of nonlinear problems. Although VLSICAP internally uses triangular finite elements with six nodes per element, the output attributes of the standalone version were always reinterpolated to a tensor product grid. This was done because of the lack of visualization facilities for unstructured grids.
Since VISTA provides dedicated support for unstructured grids, attributes defined on such grids can now be visualized with the two-dimensional graphical visualizer available in the framework. Therefore the integrated version of VLSICAP can write its attributes to the binary PIF file either on an unstructured triangular grid with six or three (by decomposing the six-node element into four three-node elements) nodes per triangle, or on a tensor product grid. Thus in the VISTA version of VLSICAP solution quantities can be displayed on its native six-node triangular grid on which the solutions are originally computed, which was impossible in the standalone version.
Providing tensor product output in VLSICP was relatively easy, since its output module was already prepared for substituting various output drivers. Thus a PIF output module was written with a compatible functional interface and linked to VLSICP. Finite element output, however, had to be introduced separately into VLSICP, and conversions had to be made for preparing grid coordinates and attribute values for PIF writing.
The conventional result (.RES) and output (.OUT) files however are still necessary even in the integrated version, since on the former the computed capacitance values are stored, and on the latter a log of the VLSICAP run is kept. While the capacitances would properly have to be stored on the PIF file in the framework version, a central logging facility is yet not available in VISTA.