Rules and Violations

 

The Rules and Violations button is used to open the PCB Rules And Violations panel, which allows easy browsing of the enabled design rules and violations in the current board layout design space. The panel provides a central point for browsing and editing rules, instigating design rules checks, and viewing individual violations as graphic overlays in the design space. The button is accessed from the PCB editor in the following ways. 

  • Home | Design Rules | Rules and Violations.

  • View| PCB| Rules and Violations

The controls at the top of the panel allow you to apply highlighting, zoom, etc., to design rules/violations in the design space.

Selecting Rules and Violations

The PCB Rules And Violations panel has sections that offer a finer scope of the design rules and violations.

  • Rule Classes - Design rules grouped by classes, such as Clearances and Widths.
  • Rules - The individual design rules of the selected class. The specific DRC can be run via the right-click menu.
  • Violations - Details of each rule violation reported by activated design rules checks.

Selecting an individual rule violation causes the design space to graphically highlight that violation. Enhanced violation graphics are drawn only on the layers on which the offending primitives reside, and that layer (if enabled) will become the active layer in the design space. When the rule violations details are enabled (see below), the editor's graphics will display the constraint value defined for the rule and indicate how the offending primitive(s) are either below or above this value.

Violation of a minimum Width rule set to 12mil.Violation of a minimum Width rule set to 12mil.

Violation of a Via dimension rule set to minimums of 50mil diameter and 28mil hole size.
Violation of a Via dimension rule set to minimums of 50mil diameter and 28mil hole size.

Note that if you have the Zoom highlighting method enabled, the design space will be zoomed-in to fit the browsed violation for a much more precise 'view' of the violating area. The level of that zoom can be varied via the panel's Magnify button.

You can also directly access violations from within the design space. With the cursor over an offending primitive, right-click and select Violations from the context menu, then select the appropriate violation to open the  Violation Details dialog.

Controlling the Display of DRC Violations

The visual display of DRC violations can be configured to maximize clarity and/or suit your own preferences by setting the style, number, and color of the graphic markers. Along with the graphic display of violation details, the design primitives can be overlaid with a graphic pattern selected from a number of styles.


Top: Violation details enabled. Middle: Violation error overlay enabled.
Bottom: Both details and error overlay enabled.

Violation Display Preferences

Control over how DRC violations are displayed using the custom violation graphics and/or a defined violation overlay is specified on the PCB Editor – DRC Violations Display page of System Preferences

Right-click Menus

The entries in each section of the panel offer a range of options via the right-click context menu. Notable right-click options for each section are:

Rule Classes

  • Run DRC Rule Class - runs all rules contained in the class. Classes may only contain a single rule (such as Short-Circuit Constraint) or a large number (typically, the Clearance Constraint class).
  • Clear Violations For Rule Class - clears the violations (both graphically and listed in the panel) for all rules contained in the class.

Rules

  • Properties - opens the Edit PCB Rule dialog that allows you to edit the properties of the selected design rule.

The Edit PCB Rule dialog can also be accessed by double-clicking on a rule entry in the PCB Rules And Violations panel.

Rule Scoping Controls

When defining the scope of a design rule, i.e. the extent of its application, you are essentially building a query to define the member objects that are governed by the rule. Use the options available in the dialog to build the query required. Depending on whether the rule is unary or binary, you will need to define one or two scopes, respectively.

For a unary design rule, controls will be provided to define a single rule scope (Where The Object Matches). Use the options available in the Where The First Object Matches region (for a binary rule) to help build the query expression. For a binary design rule, controls also will be provided to define a second rule scope. Use the options available in the Where The Second Object Matches region to help build the query expression.

Controls are identical, whether defining one or two rule scopes and are detailed in the following sections.

Where The Object Matches

  • Scoping Option - use the drop-down to select from the options to determine how to generate the scoping query expression.
When using the NetNet and Layer, Net Class, or Layer options, the field will populate with all defined nets in the design, all defined net classes in the design, or all currently enabled layers in the design, respectively. Use the drop-downs to choose the required target.
When using the Net and Layer option, the field will populate with all currently enabled layers in the design. Use the drop-downs to select the required layer.

Constraints

This region of the dialog presents the constraints applicable to the type of rule being edited. The controls vary depending upon the type of design rule being edited. Use the various controls to configure these constraints as required. In the diagram, controls highlighted in blue can be clicked on and edited, if desired. Enable any of the various options provided, if desired.

Violations

  • Properties - opens the Violation Details dialog, which provides full details of the rule constraint and the current violation. 

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