Generating Abstract View
This view is necessary for automatic layout (placement and routing) tools.
It only contains information on cell boundary, routing obstacles, and I/O pins.
To generate abstract view for inv
Then an abstract view will be generated (shown below). Please open the
abstract view and take a close look at it.
- Start Cadence using "icfb".
- Open layout view of inv to edit.
- In Virtuoso menu, select Tools ->
Abstract. This brings out a Select PR Engines window.
Make sure GE/C3 is selected then click "OK". This adds
"Abstract" to the layout menu.
- Select Abstract -> Auto Boundary. This should generate a
cell boundary box in prBoundary layer, but it might fail
with the message:
*Error* *ERROR* - no P&R routing found.
If this happens, go back to the layout tool (under Tools) and create a
prBound dg rectangle at (0.00, 0.00) and (4.80, 18.00), then switch back to the abstract tool.
If autoboundary works, make the prBound dg layer visible in the LSW, use
F4 to toggle to P (partial) select mode, and shrink the box down to the size (0.00, 0.00) by (4.80, 18.00).
- Select Abstract -> Set Cell Props... This brings out a
Set Cellview Properties form. Make sure that:
then click "OK".
- Cell Type is "standard"
- Cell Class is "none"
- Make placementClass core
- Next to Symmetry, select X and Y
Comment: If there is no proper Cell Type and Cell Class for
your cell, auto placement and routing will fail. If your do not define
placementClass Silicon Ensemble will not allow you to import the design.
If the symmetry selections are not made, you will be unable to flip cells for alternate mirroring during placement and routing.
- Select Abstract Abstract -> Abgen... This brings out
Abstract Generation form. Click "OK". If you moved the abgen.rul file to you library, you should be able to use your own library as the
Rules Library. Then click "OK".
You can now close inv abstract view, save and close inv layout view,
and then quit cadence.