The Misc Config Page

This page contains some miscellaneous settings and controls, to be described. The topmost controls on this page apply to cell handling.

Cell flattening name keys
This group contains a text entry area and an Apply button. When the Apply toggle button is in the pressed state, the FlattenPrefix variable is set to the text in the entry area. When the Apply button is not pressed, the text in the text area is retained, but the FlattenPrefix variable is unset.

This is one means by which the user can force a physical cell to always be logically flattened (see 16.4) in the extraction system. It is a bit archaic, as the extraction system will do most required flattening automatically, and use of the flatten property is the recommended way to force instance flattening.

Extract opaque cells, ignore OPAQUE flag
Checking this will cause the extraction system to ignore the OPAQUE flag applied to subcells, and attempt to extract the contents as for a normal cell. This tracks the state of the ExtractOpaque variable.

Be very verbose on prompt line during extraction
When set, during extraction lots of progress messages are displayed on the prompt line. However, this can actually slow down the process considerably, particularly if running remotely. By default, the messages are much more terse, and there is very little progress indication.

Global exclude layer expression
This group provides an Apply button and text entry area. The text entry area should contain the name of a layer, or layer expression. When the Apply button is pressed, the GlobalExclude variable will be set with the text from the entry. When the Apply button is unset, the text is ignored, and the GlobalExclude variable is unset.

If an expression is given and active, any object that touches an area where the layer expression is ``dark'' will be ignored in extraction, as if it didn't exist.

For example, one might create a layer named ``NOEX''. Then, if the layout contains features that should be ignored by the extraction system, one can enclose the features in NOEX boxes, and if ``NOEX'' is entered into the text entry area and the Apply button pressed, the marked features will be ignored.

The Association group contains settings that apply during the association operation, when electrical and physical matching occurs.

Don't run symmetry trials in association
When checked, the association computation will not break symmetry and run symmetry trials. This is mostly for debugging. The NoPermute variable tracks the state of this check box.

Logically merge physical contacts for split net handling
When set, some additional association logic is employed to detect and account for split nets in instance placements. A ``split net'' is a logical net consisting of two or more disjoint physical conductor groups. The disjoint parts of the net are connected when instances are placed, through parent cell metalization. If the schematic shows the net fully connected in the master, LVS will fail on the parent unless this check box is checked.

The MergePhysContacts variable tracks the state of this check box.

Apply post-association permutation fix
Checking this check box enables additional association logic. It applies when there is perfect topological matching between layout and schematic, but LVS is failing due to different permutations of permutable subcell contacts being assumed in the electrical and physical parts. Checking the box will enforce the electrical permutation on the physical solution, which will allow LVS to pass if the permutation difference was the only issue.

This should no longer be needed, as the two-pass association algorithm in current use should resolve these cases automatically. This check box should therefor not be checked in general, but it is possible that it might allow successful LVS in some obscure case.

The SubcPermutationFix variable tracks the state of this check box.

Maximum association loop count
This sets the maximum number of ``loops'' allowed around the association logic. There is no reason to touch this unless directed by Whiteley Research. The MaxAssocLoop variable tracks this entry.

Maximum association iterations
This sets the maximum number of iterations allowed per loop. There is no reason to touch this unless directed by Whiteley Research. The MaxAssocIters variable tracks this entry.