Binding Updates

Use the Connectivity – Update – Binding command (or lxUpdateBinding SKILL function) to increase Layout XL-compliance by improving the bindings, if you have unbound instances between the schematic and layout views due to any of the following reasons:

• The layout view was created outside Virtuoso Layout Suite XL. In this case, the logical and physical connectivity of the design may be in conflict. In addition, the number of bound instances and the number of shorts may not be as expected.
• The design is known to be LVS-clean, yet there are unbound instances and shorts in the design.
• A hierarchy mismatch exists between the schematic and the layout views, making it impossible to achieve a one-to-one device correspondence.
• The layout contains different-connectivity mosaics. The Update Binding command flattens these mosaic instances for the binder to process them. Alternatively, you can manually flatten the mosaic instances before the binder can process them.
  • If you have same-connectivity mosaics in your design, these can be handled by the binder like other layout instances. Therefore, you do not need to run the Update Binding command to flatten these mosaic instances.
  • If you do not want your mosaic instances to be flattened during the Update Binding run, you must set an ignore property on these instances.
• The layout contains route cells that were not defined in the schematic. The Update Binding command enables you to ignore such layout instances that are identified as route cells. In addition, the Update Binding command sets an extractToLevel property value of 31 to such ignored route cells, even if the route cells already have an extractToLevel property set. Alternatively, you can manually select these layout instances and add an ignore property on them. If the route cells exist within a transparent layout hierarchy, the ignore property cannot be added during an Update Binding run. To add the ignore property on instances within a transparent hierarchy requires editing the transparent instance master. The Update Binding command does not support such edits that require modifying the layout cellviews other than at the top level.

If the layout has been created using the Layout XL connectivity-aware commands, the layout view is correct by construction and the layout instances are automatically bound to the schematic. In this case, running the Update Binding command is not required. For layouts that are not Layout XL-compliant or do not have the required connectivity information, the Update Binding command improves the binding between the schematic and the layout by setting options that control how the connectivity, the manual bindings, and the design hierarchy are processed.

The improvement in bindings and the desired Layout XL-compliance may not be achieved with a single Update Binding run. The command may need to be run iteratively to achieve the desired compliance, with each iteration modifying the command based on the improvement suggestions in the Update Binding report from the previous run.

To control which issues are reported during an Update Binding run, set the following environment variables, as appropriate:

• bindReportDummies
• bindReportHierarchy
• bindReportTerminalMismatch
• bindReportUnconnInstTerms
• ignoreTermsWithNonRoutingLabels
  
  The Update Binding command cannot be undone.

Related Topics

lxUpdateBinding

LVS-clean

physical connectivity

route cells

bindIgnoreRouteCells

Layout XL-compliant

Transparent Layout Hierarchy Generation

Update Binding Report

Mosaic Instances Generation