Hints, Tips and Solutions - June 2005

Q: Is there a way to turn-off all of the generated layers so that the layout modifications can be done without them cluttering things?

A: When a project is loaded, Expert automatically creates default layer plans with the names FULL__, DATA__, CONNECT__, INPUT__. These layer plans are automatically updated when you open a cell or select one of these plans from the layer plan drop-down list in the Layer bar.

FULL__ layer plan shows all layers present in the technology.

DATA__ layer plan shows only layers that contain geometry in the current cell.

CONNECT__layer plan shows only layers present in the connectivity sets.

INPUT__ layer plan shows all layers present in the technology except generated layers. All layers that have flag Derived or Scratch are hidden.

Generated layers that appear in layout after extraction are either Derived or Scratch layers. Use layer plan INPUT__ to hide all generated layers at once (Figure. 1).

Figure 1. Default Layer Plans

Tools >> Derived Layers >> Clean Derived Layers in Whole Project or in Cell Hierarchy deletes all objects from derived layers. If extraction technology uses Scratch layers, use Tools >>Scratch Layers >> Clean Scratch Layers to delete objects from generated layers (Figure. 2). If some modifications will be done to layout, derived layers should be rebuild anyway.

Figure 2. Clean Scratch Layers command

Q: I used the Recovery Log in previous versions of Expert to keep a record of all operations executed by the user for recovery purposes, but I can’t find option “Write Recovery Log” in the new Expert QT.

A: Expert Qt version has a new recovery engine to replace the recovery log in the previous versions.

The old recovery log facility had the following disadvantages:

1. User has to be familiar with Expert Scripting Language (advanced Expert user) to execute recovery script.
   
2. The recovery log became inconsistent after saving particular cells (not whole project).
   
3. Inability to recover the data from linked libraries.

The new recovery engine is based on recovery info saved inside Expert database file. Therefore the recovery data is written independently into the current project and activated libraries. To activate Expert recovery feature, check the option “Recovery info” on the “Data Safety” page of the Expert setup panel and specify interval in minutes you want to save recovery info (Figure. 3). Expert will automatically write recovery data at the entered interval.

Figure 3. Data Safety.

NOTE. Saving recovery data does not replace the Project>> Save command you must use for saving your project.

If Expert is terminated abnormally (Expert freezes, computer hangs or you lose power unexpectedly) you will be able to recover unsaved data. Restart Expert and load the project file, which may contain unsaved information. When unsaved data are detected the message box will pop up asking whether you want to save (discard) recovered data or continue loading project with recovered information. The last choice is allowed to open and examine recovered cells (they will be marked as modified). You can save or discard whether specific cells or whole project by Save project or Close project without saving.

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