Generating Abstracts

Whether you are generating abstracts for an entire library or for a few hierarchical blocks, the approach is typically the same. You can initially focus on a small subset of cells or blocks, establish option settings for this subset, and then process the remaining cells or blocks in a single run.

To generate abstracts:

1. Choose File – Library – Open to view the Open Library form.
   This form lists the libraries that are read in from the cds.lib file located in the run directory on startup. You can either open an existing design library or create a new one.
2. Select the library you want to process. The library path tells Abstract Generator where to find existing information about the library and where to store the intermediate and final views created during abstract generation.
3. You can attach a technology library to the design library you have selected to process. If you attach a technology library to the design library or if there is a technology library associated with the design library, Abstract Generator uses the existing technology library information, such as the.abstract.options file.
4. Import various types of data, such as LEF, DEF, GDSII, and OASIS if the selected design library does not contain layout or logical views of cells or views created by Abstract Generator in a previous session.
5. Choose Select and Sort functions of Abstract Generator to locate the cells you are interested in, and then use the manual and automatic Distribute functions to move these cells into the appropriate system or user bins. These commands are available on the Cells menu.
   Abstract Generator uses the concept of Bins to distribute the library cells into a number of mutually exclusive sets. When you import cell information into Abstract Generator, it is by default assigned to the Core bin. This might be sufficient for certain libraries, but there will be cases where you require a more sophisticated distribution before you start processing your cells.
6. Identify the cells with which you want to experiment, and begin to Generate Abstracts for these cells. Each of the three main flow steps – Pins, Extract, and Abstract have their own set of options that control the way in which any cell is processed. You can make your initial option settings either before you start generating abstracts or when you run any of the individual steps.
7. Inspect the results in the generated abstracts using the Cell pane, layout, and Report File and Log File.
8. Modify the option settings as required and rerun the relevant steps to generate a new abstract after you assess the abstracts.
   When you change options related to a particular step, the view created by that step is invalidated along with all “downstream” views present for that cell.
9. Choose Cells – Revalidate Selected to re-validate invalid views. When you are satisfied with the results of your tests and the options you want to use for each bin, you can process the remaining library cells either bin-by-bin, step-by-step, or all at a time.
10. Choose File – Export – LEF to translate cell abstracts into LEF, which can be used as input to place-and-route tools.

Related Topics

Cell Preferences for Abstract Generation

Inspect the Results of Generated Abstracts

Options and Status Files in Abstract Generator

Attaching Technology Information to a Library in Abstract Generator

Opening a Library in Abstract Generator

Creating a Library in Abstract Generator

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