Electrical Constraints
For any high-speed design, first go to the Worksheet Selector on the left, then set up electrical constraints. Navigate to
Electrical Constraint Set > Routing > Wiring.
We can control the Topology, Stub Length and Max Exposed Length of traces, but first set those values as rules. Those rules
(Electrical Constraint Sets) can be applied to the desired traces.
We will go through each rule and set them within the Constraint Manager on the schematic side.
Electrical Wiring Topology
Set specific routing paths for technologies like DDR3 and T-branch to minimize signal attenuation due to PCB material
properties. Or Daisy Chain or star topologies.
Diagram showing the prioritized routing of critical nets on a PCB
Definition: Wiring topology involves organizing the connections between different nets on a PCB to achieve a certain
outcome, such as minimizing signal reflections, signal attenuation or voltage drops.
Example: Let's ensure that a DDR3 Command or Address net follows a daisy-chain topology.
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OrCAD X High-Speed Digital Design Guide
