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The Params page

The upper half of this page provides entry areas for parameters used by the interface.

This is an option menu which is used to set the length units used in files produced by the interface. Choices are meters, centimeters, millimeters, microns (the default), inches, and mils. The selection, if not the default, will set the FhUnits variable. Similarly, setting the variable with the !set command will update the state of the menu. The choice currently in effect will be applied when input files are generated. The choice of units will not affect the computed inductance/resistance.

Value: real number 1e2-1e5.
When a non-Manhattan polygon is ``Manhattanized'' for FastHenry, it is converted to an approximating Manhattan polygon. The value in this entry is used to set the minimum rectangle width and height allowed in the decomposition. It sets, and is set by, the FhManhGridCnt variable. The minimum size is given by
The default entry value is 1000. Larger values are more accurate but slow processing, sometimes dramatically. The area_of_interest is the layout area being processed for input to FastHenry.

The lower half of the page allows one to crudely refine the raw segmentation. By default, this is not enabled, so that only tiling provides refinement. This may be a good starting point for a third-party refinement algorithm, but with present FastHenry programs is unlikely to provide accurate results as-is. When enabled, the crude refinement should provide somewhat better results.

The refinement algorithm works as follows. First, the total volume of all conductors is calculated. This is divided by the FhVolElTarget as entered. The cube root is taken, which provides a length which is used as a maximum. If a side of a tile exceeds this length, it is subdivided. This is repeated until no tiles have sides larger than the calculated length. The total number of tiles (or ``volume elements'') is approximately the target value entgered. The total number of segments is approximately six times larger.

The refinement is ``crude'' due to each refined volume element being approximately the same size. If the size is small enough, sufficient spatial resolution for accurate calculation is achieved. This resolution is needed along edges, and at corners, where there are strong field gradients, but is gross overkill for most areas. Since the solving time is related to the total number of segments, this type of refinement is very inefficient with respect to memory use and execution speed.

This check box will enable or disable the refinement. When pressed, the FhVolElTarget entry will become un-grayed, and internally the FhVolElTarget variable will be set to the number shown in the FhVolElTarget entry area. When the Enable button is set inactive, the FhVolElTarget variable is unset. The Enable button state will reflect whether or not the FhVolElTarget variable is set.

This entry area is seensitive only when the Enable check box is checked. It tracks the value of the FhVolElTarget variable, which can be set to a real value of 1e2 - 1e5. This will be the approximate number of refined tiles generated in the input file.

next up previous contents index
Next: The Jobs page Up: The LR Extraction Panel Previous: The Run Page   Contents   Index
Stephen R. Whiteley 2019-11-22