Collaborative management of design constraints

Most design teams would agree that as circuit complexity continues to increase, so has the criticality for efficient rules-driven design (aka constraint-driven design). These increasingly complex circuits usually require increasingly complex constraints that can include, for example, nested constraints, and/or constraints specified with conditional parameters in order to allow them to be evaluated in the context of the design. As constraints grow in quantity and complexity, more sophisticated tools are required in order to accelerate the tasks of constraint entry and constraint management. As is the case with schematic entry or PCB layout, a real-time collaborative approach that efficiently supports multi-user constraint entry and management will reduce cycle time and contribute to improving time-to-market. The key features of a collaborative constraint management system include:

• Multi-user concurrent access – Support for multiple users concurrently accessing and editing the same constraint set.
• Real-time visibility of new entries – As entries are added, they should be visible in real-time to all users viewing or editing the constraint set.
• Real-time locking of objects under edit – An entry that is being added or edited should be locked in real-time until the addition or edit is completed. The user performing the addition or edit should be displayed to all other users viewing or editing the constraint set (Figure 1).
• Visible feedback of new and edited entries – After an addition or edit is completed, the object should be highlighted to provide visible feedback of the modification to all concurrent users.
• Change documentation – Support for real-time comments providing the rationale for constraint additions or edits that all other users can read.
• Notification to constraint consumers – As constraints are added, edited or removed, real-time notification should be provided to any tool in the flow that is a consumer of the constraints.

Figure 1 – Real-time locking of a constraint under edit

Unfortunately, many ECAD solutions only support serial constraint edits performed by one user at a time to ensure there are no conflicts or duplications. The Mentor Graphics Xpedition Constraint Manager, however, supports real-time collaborative constraint management. It provides a single, integrated constraint entry and edit tool for design, layout, analysis, and manufacturing rules. A short video demonstrating real-time concurrency during constraint management along with a constraint management datasheet are both available for more in-depth information.