How Design Rules are Applied

Different design rules are applied in different situations. Certain rules can be applied as you design, by enabling the online design rule check (DRC) feature. A violation of a rule is flagged as soon as the violation occurs during placement. You may prefer to design first and check for violations later. If this is the case, you could enable the batch DRC feature, which will apply a certain set of rules when launched and provide feedback via a report. Some rules are only applied at certain times and during software operations, such as autorouting, autoplacement and manufacturing output generation.The PCB Editor only applies each rule when it is appropriate. A rule's definition specifies when that particular rule is applied. To reiterate, each rule is applied in one or more of the following situations:

• Online Design Rule Check (DRC) : running in the background, as you work, flagging and/or automatically preventing design rule violations of certain rule types
• Batch DRC : allows you to manually run a DRC at any time during the board design process, on all enabled rule types, and obtain a report
• During a software operation : certain rules are monitored during a software operation including: polygon pour, autorouting, autoplacement and output generation. Examples of these include the mask expansion rule which is monitored during output generation and the routing via style rule which is monitored during autorouting.

The following table summarises where each of the individual rule types are applied: