Generate Abstracts
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. You can use the Bin Options form and Running Step Abstract form for option settings
You can access the Bin Options form by using the Bins - Options menu command. In this form, you can view and modify all options associated with the entire abstract generation flow.
Whenever you run any flow step, Abstract Generator opens the Running Step Abstract form. This form allows you to modify only the options that are relevant to the steps about to be run.
When you are satisfied with the options settings, use the four flow steps to generate abstracts for the selected cells. You can run the steps either one at a time or all at once for any or all of the cells.
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Step
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Description
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Pins
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In the Pins step, Abstract Generator creates a place-and-route boundary for the cell and the starting pin shapes for each of the nets to be extracted. It then matches the pins created against those described in any logical view present and appends the appropriate pin direction.
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Extract
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In the Extract step, Abstract Generator derives which shapes are connected to which nets by tracing the connectivity from the pin
purpose shapes created during the Pins step.
The tool creates a shape with purpose net in the top level of the extract view, and for each such shape creates a pin on the appropriate net. The overlap boundary is also calculated if required.
Finally, Abstract Generator uses the antenna options to create library process antenna information for custom blocks and standard cells. The resulting antenna model helps mitigate the problem of gate damage caused by chemical and mechanical polishing.
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Abstract
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In the Abstract step, Abstract Generator adjusts the pin shapes created during the Extract step to create the final shapes required by place-and-route tools. It then fractures these pin shapes into rectangles.
Next, Abstract Generator applies a layer blockage model selected by the user to create the final blockage geometry in the abstract. The blockage geometry is then ally fractured into rectangles.
It then removes from the abstract all layers other than those with purpose pin, blockage, or boundary and deletes the instance hierarchy. At this stage, all the required geometry is at the top level of the abstract.
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