7. Click OK. This brings you back to the Select Layer Sets window.
8. Click the HS_TOP_INNER from the Available Layer Sets list. It will move over to the Assigned Layer Sets section. Click OK.
9. Finally we will apply this ECSet (ECS1) to the DATA(15) Net Class as an example, as shown below.
10. Scroll horizontally to the final column named Layer Sets.
11. Some nets in the Net Class will pass or fail the Name within the layer set, because not all the nets are routed on the TOP,
GND or INNER1 layers. It is working as intended.
Impact: The layers a signal goes through vertically affect how much coupling and EMI is passed through the PCB. Utilize the
constraint manager to avoid unnecessary EMC issues in PCB Design.
Return Path
Purpose: Reduce electromagnetic interference by checking that signals are following a proper return path.
OrCAD X Constraints support return path checking for Impedance and EMI.
Steps to implement return path checks in OrCAD X Presto PCB Editor:
1. Within the Constraint Manager, go to the Electrical > Electrical Constraint Set > Routing > Return Path worksheet.
2. Right click on the Dsn cell name (P3449_B01…) create an Electrical CSet, give it a name, then it will add itself to your list
of ECSets (see below).
3. Whether you create an ECSet or use an existing one, you have multiple options available for return path checks.
4. You can set the right reference Nets and layers for your signals.
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OrCAD X High-Speed Digital Design Guide
