next up previous contents index
Next: The Misc Config Page Up: The Misc Config Button: Previous: Ground Plane Handling   Contents   Index

The Device Config Page

This page contains controls that correspond to device-related extraction variables.

Device Block
Pressing the Device Block button produces a drop-down list of device blocks from the technology file, plus three additional buttons: New, Delete, and Undelete. The device blocks are listed in order of their definition, as the block name followed by the prefix, if any. Pressing New or any of the device block name entries brings up a text editor loaded with the indicated block, or empty for New. The text for the device block can be entered into the editor. Adding a block with the same name and prefix (or lack of a prefix) as an existing block will overwrite the existing block. Saving with the Save button in the editor will update an existing block or add a new block to the internal device list. The Save button in the editor does not save to disk. The Save Tech command can be used to generate a new technology file which will contain the new block, or the Save As button in the editor can be used to save the block as a file.

To delete a device block, press the Delete button in the Device Block menu, then select a device block from the same menu. That block will be removed from the menu. The name will disappear from the menu, and it is removed from consideration in extraction. The block can be restored with the Undelete menu entry, but only one deletion is remembered.

Don't merge series devices
If checked, series-connected devices will never be merged during extraction, overriding any Merge directive in the corresponding device blocks of the technology file. This tracks the state of the NoMergeSeries variable.

Similar devices may be series-merged if the common connection has no other connection. It is occasionally useful to suppress merging to individually measure the components of segmented devices, or in cells where the common contact may not have a connection that is currently in scope.

Don't merge parallel devices
When checked, parallel-connected devices are never merged during extraction, overriding any Merge directive in the device blocks of the technology file. This tracks the state of the NoMergeParallel variable.

If is occasionally useful to suppress parallel merging to individually measure segments of a multi-component device.

Include devices with terminals shorted
By default, if an extracted device is found to have all terminals shorted together, it is ignored. If this check box is checked, such devices are kept, allowing their parameters to be reported. This tracks the state of the KeepShortedDevs variable.

Don't merge devices with terminals shorted
When including devices with all terminals shorted, checking this box will prevent such devices from being merged as parallel devices, if parallel merging is enabled for the device type. This tracks the state of the NoMergeShorted variable.

Skip device parameter measurement
When this box is checked, device parameter measurement will not be performed during extraction. This may save time if the user is interested only in topology. This tracks the state of the NoMeasure variable.

Use measurement results cache property
When this box is checked, the extraction system will read and update (creating if necessary) the measures property (property number 7106) which is used to cache measurement results (see 16.7). The measurement of device parameters can be time consuming, and the caching can speed up the extraction process significantly. However, using the measurement cache may require user intervention to maintain coherency. If a device layout changes, the user will have to manually update the cache in order to obtain updated parameters. With this box not checked, the default condition will force actual computation of device parameters, and avoid all use of the caching mechanism. This is appropriate while a cell is under development, to avoid cache coherency issues.

The UseMeasurePrpty variable tracks the state of this check box.

Don't read measurement results from property
This setting is ignored unless Use measurement results cache property is checked. When this box is checked, the extraction system will not read the measures property (property number 7106) which is used to cache measurement results. When measurement results are required, they will be computed. The property will still be updated, after association, provided that Use measurement results cache property is set. Thus, by setting this check box and forcing association, one can get a fresh set of measurement results into the measures properties.

The NoReadMeasurePrpty variable tracks the state of this check box.

The remaining controls apply to the numerical solver used to extract resistance and (microstripline) inductance.

The default mode of the solver is to divide the device body into a grid such that the number of grid cells is fixed, independent of device size. This gives a predictable and constant measurement time per device, however it may provide less accuracy than other methods.

One can also choose to use a fixed grid size, in which case physically larger devices will take longer to extract, but computed values may be more accurate.

A third choice is to tile the structure, if possible, by using the largest grid such that all body and contact boundaries fall on grid. This is likely to provide the best accuracy if tiling succeeds.

Set/use fixed grid size
If the check box is checked, the solver will use a fixed grid size as given in the numeric entry area. When checked, other controls in this group are grayed and their states ignored. This tracks the state and value of the RLSolverDelta variable.

Try to tile
When checked, the solver will try to use a grid that falls on every edge of the contacts and device body. This tracks the state of the RLSolverTryTile variable.

Maximum tile count per device
When tiling is enabled, this entry area will set the maximum number of tiles allowed in a device. This tracks the state of the RLSolverMaxPoints variable, and defaults to 50,000.

Set fixed per-device grid cell count
This entry area supplies a number of grid cells to use per device. In this mode, the time required for extraction is close to constant, independent of device size. This mode is used when not tiling, and not using a fixed grid size. This tracks the state of the RLSolverGridPoints variable, and the default value is 1000;


next up previous contents index
Next: The Misc Config Page Up: The Misc Config Button: Previous: Ground Plane Handling   Contents   Index
Stephen R. Whiteley 2017-10-02