Issue link: https://resources.pcb.cadence.com/i/1532920
Part 3 - Advanced Constraints Advanced constraints include rules for high-speed complex printed circuit boards. Standard PCBs are usually 300 compo- nents or fewer, where the primary concern is designing for manufacturing, fabrication, assembly, and testing, then maybe differential pairs and single-ended impedances depending on the protocols in your design. Complex high-speed PCBs however need considerations for impedance control, differential pairs, inter-pair and intra-pair skew, a limit on the number of vias and other such factors that manage signal integrity and electromagnetic interference. Advanced Constraints also account for typical high-density interconnect boards, military grade PCBs, and rigid-flex or flex PCBs. Anything outside the normal DFM considerations would be considered advanced constraints for a printed circuit board. Now that we understand the difference between regular and advanced constraints let's look at ways to turn on or off the kinds of constraints we should enforce in the Constraint Modes section. Constraint Modes Implementing USB constraints in Cadence OrCAD X. 1. Open Constraint Manager. 2. Go to Analyze - Analysis Mode – Electrical. 3. Enable all the options under Electrical Modes and Electrical Options as seen in the image below. 3 www.cadence.com OrCAD X Constraint Management Guide