During the commit hierarchy process the top level UPF power domains associated

During the commit hierarchy process the top level upf

This preview shows page 412 - 414 out of 455 pages.

During the commit hierarchy process, the top-level UPF power domains associated with the plan groups are pushed down into a new child cell view. This also makes it possible for the top-level design’s UPF constraints to be properly transferred and maintained. Embedded voltage areas and power domains associated with those voltage areas are also pushed into the child cell. Near the end of the commit process, after the top-level hierarchical cell instance is replaced with a top-level child cell instance, all corresponding power domains are removed from the top-level cell, along with any voltage areas associated with the pushed down power domains. This is done to avoid the duplication of power domains across the hierarchy. Any top-level voltage area which was coincident with the plan group boundary, is also removed from the top cell and treated as DEFAULT_VA within the child cell instance.
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Chapter 14: Committing the Physical Hierarchy Converting Soft Macros to Plan Groups 14-11 IC Compiler Design Planning User Guide D-2010.03-SP4 The supply set handle specified by using the -supply option must be in a higher scope than the specified power domain. If extra supplies are defined by using the create_power_domain –supply {extra_supplies} command, only those supply sets can be used. In this case, no extra domain-independent nets can be used, unless they are bound to a supply set that is allowed or they are directly specified in the domain strategies. If no extra supply is defined, then all supply sets and domain independent nets within and above the power domain scope are available for the specified power domain. Note: If UPF power domains are not completely defined within the hierarchical cell instance, in other words they are larger than the plan groups associated with them, it means they might contain UPF elements that are outside the plan group and therefore, they cannot be committed. Converting Soft Macros to Plan Groups After plan groups are committed into soft macros, you can “uncommit” the physical hierarchy by converting the soft macros back into plan groups. The physical hierarchy is flattened into the parent. Physical objects from the soft macro are “pushed up” to their relative positions in the top CEL view. Any physical objects that are connected to power and ground nets will be connected to their appropriate nets in the top CEL view, and any objects that have properties set in the soft macro will have the same properties set in the top CEL view. To uncommit the physical hierarchy, 1. Choose Partition > Uncommit Soft Macros. The Uncommit Soft Macros dialog box appears. Alternatively, you can use the uncommit_fp_soft_macros command. 2. Choose whether to convert all soft macros or selected soft macros to plan groups.
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