Instance Cloning
- Cloning Instances with no Schematic Counterpart
- Cloning Iterated Instances
- Cloning Instances with Inherited Connections
- Cloning Synchronous Clones
- Creating Modgens
Cloning Instances with no Schematic Counterpart
The Generate Clones command correctly handles layout instances with no schematic counterpart (clone dummy devices), including those that are part of a chain.
Layout XL considers a layout instance to be a dummy device if:
- The instance or its master has at least one property included in the list of Properties used to ignore objects during check on the Parameters of the Connectivity form.
-
The instance has the
physOnlyattribute set. - The instance component type is set as FILLER, STSUBCOUNT, or BOUNDARYCELL.
When Layout XL detects a dummy device among the objects in the clone source, it generates a similar instance with the same properties in the target structure. This new instance is automatically named Ix, where x is an appropriate integer value assigned by the database.
Cloning Iterated Instances
Because they all have the same master and same connectivity, cloning considers the individual bits of an iterated instance to be equivalent. Consequently, cloning cannot guarantee the same relative placements of devices in the clone source and the matching targets. If required, you can change the relative placement of instances in the target structure manually by changing the correspondence of the individual instances in the source and the target.
Cloning Instances with Inherited Connections
If a layout instance master terminal has an inherited net expression (an implicit inherited connection) for a global layout net, Generate Clones creates a physical-only layout terminal with no schematic equivalent. The physical-only terminal has the physOnly property set to t so that it can be correctly ignored by Layout XL functions such as Update Components And Nets and Check Against Source and by the digital applications further on in the design flow.
Cloning Synchronous Clones
You cannot create a synchronous clone that contains a synchronous clone. If the clone source includes groups of type syncClone, the groups are created as regular groups in the generated clone.
The only exception to this is if you are generating a synchronized family and the clone source comprises a single synchronous clone. In this case, matching target structures are generated as synchronous clones belonging to the same synchronized family.
Creating Modgens
You can create synchronous clones using Modgen figGroups as the source. The resulting clone family then comprises the existing Modgen figGroups in the clone source, and basic figGroups, called "pseudo-Modgen", in other clones.
A pseudo-Modgen figGroup cannot be edited. However, if you attempt to edit the figGroup, the Edit Cloned Modgen pop-up form displays, which suggests that the selected figGroup cannot be edited but the Modgen synchronized with the figGroup can be edited instead.
You can choose to hide the Edit Cloned Modgen pop-up form by setting the disableVXLClonedModgenEditPopUp environment variable to t. This results in the modgen synchronized with the pseudo-modgen figGroup to automatically get edited when Editing In Place a pseudo-modgen figGroup.
If you were to Edit In Place a synchronous clone and then create a Modgen inside the clone, the clone will be desynchronized. You should create the Modgen first and then use it as a clone source to create a Modgen inside the clone.
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