Routing Concerns
Although the signal may require the shortest possible assignment, you must also consider routing. If the resulting shortest assignment results in connectivity crossing, you may need an additional routing layer. If an additional layer is not possible (or desired), you should make an assignment that selects the closest component I/O that also minimizes any signal crossing.
For general component I/O assignment, a utility should be available that scans both the die and the component I/O, take into consideration power, ground, and priority signals, and develop an optimized die-to-component netlist. Optimization should be based on overall routing capability of the component. For multiple dies, this process may be incremental. During each step, you select the die I/O of one or more dies and direct the assignment to a specific location of the component. Otherwise, poor assignment may result.
Related Topics
Die-to-Component I/O Net Assignment
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