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The Check In Background Button: Initiate Check in Background

The Check In Background button in the DRC Menu initiates design rule checking on a region or cell. Operation is similar to the Check In Foreground button, however a new background process is created to actually perform the checking.

The user is requested to point to the corners of a rectangle defining the region to be checked. Simply clicking will cause checking of the objects under the pointer. Holding and dragging will cause checking of all objects which overlap the ghost-drawn rectangle, when the button is released. If the user presses and holds without moving the pointer for a brief period, the ghost-drawn rectangle corner will be attached to the pointer, and pressing a second time will complete the operation. Instead of a mouse button press, pressing Enter will cause the entire area of the current cell to be checked. All objects in the current cell and its subcells which overlap the specified region are checked.

Unlike the Check In Foreground command, errors are not marked on-screen. The Update Highlighting button can be used to generate the highlighting after a background run completes. If the Show Errors mode is active, and the current cell is the same as that being checked, when a background job terminates, the error display window is popped down and the mode terminates.

The spawned process is set to ignore the SIGHUP signal, so that the process will continue to run if the user's shell is destroyed and/or the user logs out. This is the preferred method by which large batch DRC jobs can be performed. The spawned process can be stopped or killed using the job control functionality of the user's shell. There can be multiple spawned processes executing concurrently.

This process will create an errors file in the current directory named drcerror.log.cellname.PID where PID is the process id of the spawned process. A pop-up message will appear in Xic when a spawned process completes.

Under Windows, this works by executing a batch-mode Xic process in the background. However, the entire cell is always checked, any rectangle specification is ignored.


next up previous contents index
Next: The Check In Region Up: The DRC Menu: Design Previous: The Check In Foreground   Contents   Index
Stephen R. Whiteley 2012-04-01