Constraint

Constraint
The lack of ability to further proceed with any type of action as certain limitations or restrictions are set due to certain factors. Constraint is often looked upon as a negative aspect however, limited parameters can enhance or even benefit a certain project if understood and worked with effectively. While limitations are set into play at times, these may allow a designer to view a project through a different perspective and thus provide a better design solution as it may not have otherwise been foreseen.

A constraint is also a design target and requirement that must be met in order for the design to be considered successful. We use constraints to ensure the design meets its performance goals. For example, a chip may be required to run at a specific frequency in order to interface with other components in a system. Constraints can be categorized into Timing Constraints and Physical Constraints. Timing Constraints allow us to set and identify input and output timing information or maximum delay. Sometimes, tightening the timing constraint helps to meet goals. Physical constraints determine the size, shape and utilization of design.

“Design Constrainst”,Arctel Corporation, May 2007 http://www.actel.com/documents/des_constraints_ug.pdf