Cadence Mixed-Signal Circuit Design Environment User Guide
Partitioning Your Design
Product Version 5.0
Effect of Null Binding
From IC 5.0 onwards, HED will allow null binding specifications in configurations. Cells and
instances with null binding specifications will effect design traversal and partitioning as
During design traversal, if partitioner finds a cell binding set as null binding, then the
partitioner will give a warning about this cell binding and will ignore the cell and all
its instances everywhere in the design hierarchy.
During traversal, if partitioner find an instance's binding set as null binding, then the
partitioner will give a warning about this instance and will ignore the instance.
Mixed signal simulation will work smoothly, if none of the cells and instances with null binding
specifications form a part of the circuit to be simulated.
Changing Stop View Sets
The analog stop view set is a list of all valid stop views for the circuit simulators. The digital
stop view set is a list of all valid stop views for the logic simulators. These sets are mutually
exclusive: no view can be specified in both sets.
The partitioner locates every stop view in the HED Global Bindings Stop List in either the
analog or the digital stop view set. The partitioner requires that each view in the Global
Bindings Stop List must be a member of either the analog stop view set or the digital stop
For example, if the view name Spectre is in the Global Bindings Stop List, the system checks
the analog and digital stop view sets to see where this view is specified. Because Spectre is
in the analog stop view set, all stopping instances using Spectre views are analog instances.
These sets need to be enabled and modified to include any unique stop views needed for your
proprietary simulation software. In most cases, the sample sets should not need modification.
Note: Do not confuse the analog and digital stop view sets with
inherited view list constants in the HED. The
strings are different
HED inherited view list names. They do not indicate that instances using
will be simulated by the analog simulator. Many HED inherited view lists can be created to
control the expansion of the design hierarchy, allowing certain branches to be expanded using
predominantly analog schematic/layout views, analog behavioral views, digital schematic/
layout views, or digital behavioral views.