Automatic Combination of Physical Multicores During Wiring Synthesis

You can use a ‘Combine Physical Multicores’ constraint to specify that wiring synthesis automatically combines physical multicores that belong to the same combined logical multicore. This is so that users avoid manual steps.

Note

See Overview of Rules and Constraints for high-level information about working with rules and constraints.

You can use the constraint to combine all combineable physical multicores of a combined logical multicore, or an identified subset of physical multicores.

This constraint uses existing multicore combination rules in order to determine which physical multicores can be combined, with the exception that physical multicores between splices cannot be combined using this constraint.

When running wiring synthesis, you must select the Combine Wires/Multicores action in order for synthesis to reference the constraint.

You add the constraint to a connector, slot, or a design. You define it so that it would match against one of the following:

• A combined logical multicore (in which case all valid physical multicores for this combined logical would be combined)

• A set of logical multicores that match the constraint and are part of the same combined logical multicore

Example of a Constraint Matching a Combined

Logical Multicore

At a connector, there are three physical multicores MC101, MC102, MC103 implementing three logical multicores (MCA, MCB, MCC).

The three logical multicores have been combined into logical multicore MC_ABC (note a user has renamed the combined logical multicore).

You add a ‘Combine Physical Multicores’ constraint: Do combine physical multicores for Combined multicore matching Name = MC_ABC

During synthesis, the physical multicores MC101, MC102 and MC103 will be combined.

Example of a Constraint Matching an Individual

Logical Multicore

At a connector, there are three physical multicores MC101, MC102, MC103 implementing three logical multicores (MCA, MCB, MCC).

The three logical multicores have been combined into logical multicore MC_ABC (note a user has renamed the combined logical multicore).

You add a ‘Combine Physical Multicores’ constraint: Do combine physical multicores for Logical multicore matching Name = MCA|MCC

During synthesis, the physical multicores MC101 and MC103 will be combined. MC102 will be left uncombined.

Limitations

The following limitations apply to synthesis using this constraint:

• If there are several possible multicore combinations, not all of them can be combined in one go. For example, the following lists overlap with each other: [MC87138,MC87192,MC89867,MC89846]

[MC87138,MC87194,MC89867,MC89846]

Only MC87192 and MC87194 are different in the combinable lists. If synthesis combines any of these, the other list cannot be combined. Synthesis combines one of the lists and discards all other lists that overlap.

• As synthesis combines multicore groups one after the other, it is possible that some of the groups won't remain combinable. In this case, a message is displayed.

• After synthesis combines multicores, newly created combined physical multicores become combinable with other multicores. Synthesis does not perform multiple passes of combination. You will have to run synthesis again in such a case.

• When the constraint is trying to combine a subset of the logical multicores, if an already combined physical multicore exists, synthesis cannot identify the source multicores correctly so cannot evaluate the constraint against it.

• Multicores connected to a splice on both ends cannot be combined using the constraint.

Note

You can run a ‘Physical multicore that breaks combination rule’ design rule check to identify physical multicores that break any “Combine physical multicores” constraint. The check also reports where a physical multicore cannot be validated because of conflicting constraints.

Parent Topic:

Combined Signals and Combined Wires

Capital Systems Integrator User Guide, 2512.2606

Unpublished work. © 2026 Siemens