Issue link: https://resources.pcb.cadence.com/i/1526746
KEY DIFFERENCES AND IMPLICATIONS AMONG NET CLASSES, GROUPS, AND CONSTRAINT REGIONS As stated, for complex PCBs, we need classes, groups, and regions to create a robust set of rules that will make our design reliable or right the first time. The scope, application, and flexibility vary for each of these constraint types. Below are the distinctions, pros, and cons of each of them: 1. Scope: a. Net Classes: Domain-specific b. Net Groups: Cross-domain c. Regions: Area-specific on the PCB 2. Rule Application: a. Net Classes: Can have class-to-class rules (e.g., spacing between different classes) b. Net Groups: Cannot have class-to-class rules c. Regions: Can have rules that override global or class-based rules within the defined area 3. Flexibility: a. Net Classes: Most flexible for domain-specific rules b. Net Groups: Best for general organization and basic rule application c. Regions: Most powerful for managing complex board areas with unique requirements For more details on which constraints you can set, see the CM hierarchy chart below. Constraint Management Hierarchy Chart Benefits: As we have seen, there are major benefits to having constraint regions in your designs. The top two benefits are: f Allowing for area-specific rule application f Helping manage complex designs with varying and often unique requirements 28 www.cadence.com Part 1 of 5