Full Flow Example

001_full_flow : Full Flow Example

This example demonstrates running Guardian Design Rule Checking on a layout in the Expert interactive layout environment, and viewing any violations found.

Requires : Expert, Guardian

Minimum Version : Expert 4.8.8.R, Guardian 4.8.8.R

You will also need to download, from this example's web page, the two data files: drc_full_flow_28.eld (the design database) and drc_full_flow_28.dsf (the DRC script).


1. Opening the layout in Expert

First start the Expert layout editor program, either with the command expert or by clicking the expert icon.

From the main menu bar at the top, click File->Open to open the Load Project menu, navigate to the directory into which the drc_full_flow_28.eld design database file was downloaded and Open it.

This will call up the Open Cell(s) menus, and here double-click mux4 , the top-level cell. By default this shows the hierarchical view of the design; you can see the full details by clicking View->Cell View->Flat .

See Figure1


2. Setting up DRC

The next step is to load the DRC script (also known as deck or runset). From the main Expert menu, click Verification->DRC->DRC script panel. This pops up the DRC Script Panel , and in here click File->Open to open the Select DRC Script File(s) menu, navigate to the directory into which the drc_full_flow_28.dsf DRC script file was downloaded and Open it. The DRC script is then shown in the DRC Script Panel .

See Figure2


3. Running DRC

You can enable progress bars, to monitor progress of the run, from the DRC Script Panel with Setup->Current DRC script run preferences... and in the popup window check Script progress bar and Command progress bar. If the progress bars are not enabled you will instead see a timer icon while the DRC is running.

The Setup->Current DRC script run preferences... menu also contains further options to customize the run, for example to limit the number of errors output or show the run log.

To run DRC, click DRC->Run in the DRC Script Panel


4. Selecting and Loading DRC Results

After DRC has been run, any DRC violations found can be viewed interactively on top of the original layout in Expert. From the Expert main menu, first load the DRC results into the Expert layout database with Verification->DRC->Errors->Load Errors. This opens the Load DRC Errors menu.

See Figure3

The first panel, Runs , in the Load DRC Errors menu shows one line for every time you have run DRC. Normally you will only be interested in the latest run, but it can be useful to see and compare the results from previous runs, for example to check that any fixes made to the layout have been successful. You can delete any previous runs that are no longer of use.

The second panel, Checks , shows a list of the individual DRC rule checks for the selected DRC run. By default it only shows rule checks which found errors, but clicking Show All will show every rule check done, even if it did not find any errors. If there are only a few errors found you can click Select All so that all the errors will be shown on the layout together, however if there are a lot of errors this can make it difficult to view individual errors, so you can select specific errors and look at them one at a time.

The final panel in Load DRC Errors is Errors and Cells. This allows further refinement of the error viewing when hierarchical error report is selected, but is not used in this example.

After selecting the required errors to view, click Load at the bottom of the Load DRC Errors panel; this loads the selected DRC errors into the layout database and they can now be viewed on the layout.


5. Viewing DRC Results

After Loading the DRC errors in the previous step, you can now use the Expert interactive error viewing facility to zoom into, and show explanations of, the errors.

To do this, click Verification->DRC->Errors->First error to show the first error , then Verification->DRC->Errors->Next error to show subsequent errors. There are several options to refine this, for example Verification->DRC->Errors->Filled error markers will show the error bars filled in. See Figure4 and Figure5 .


Note that all of the DRC operations can also be accessed directly from icons in the menu bars, rather than using the cascading menu commands shown in this text. Holding the mouse over an icon shows its function, or you can refer to the manual for a full description of the icons and the commands.