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The Set Defaults Button: Set Default Limits

The Set Defaults button in the DRC Menu brings up a panel which allows the user to set limits and other parameters used in design rule checking. The first limit is on the number of errors reported in batch mode checking (with the Check In Foreground or Check In Background buttons). If this limit is reached, the checking aborts. Setting this limit (or any of the limits) to zero will inhibit the limiting.

The remaining limits pertain to interactive mode (the Enable Interactive button is active). These checks are performed after every operation which modifies the physical geometry in the database. Often, the pause can be quite substantial, and it is preferable to minimize the delay, at the expense of thorough testing. Testing can be performed at a later time using batch mode. The interactive time can be limited in two ways: by limiting the number of objects checked, and by actually setting a time limit. Of course, interactive testing can be switched off entirely with the Set Interactive button. The number limit specifies the maximum number of objects checked per test cycle. The time limit, specified in milliseconds, will terminate testing when the time limit is reached. The final choice is a yes/no as to whether to test subcells that are moved, copied, or placed. This is often very time consuming, as all objects in the subcell and its descendents are checked. If the subcell has been checked previously, most of the checking is redundant and can be skipped.

The remaining buttons allow selection of the error recording level. The default is to record only one error per object. With many errors, this can cut evaluation time, and may be useful for a first pass. The second choice outputs a maximum of one error of each type (i.e., corresponding to each DRC keyword) per object. The third choice will output all errors found. This can lead to redundancy, as certain violations may be reported for each edge of the offending object.


next up previous contents index
Next: The Set Flags Button: Up: The DRC Menu: Design Previous: The Clear Errors Button:   Contents   Index
Stephen R. Whiteley 2012-04-01