Ports

You need to specify the parameters for the ports to be used in Sonnet. You define the Sonnet ports by adding Virtuoso pins to your SonnetEM view which are converted to Sonnet ports. All pin types, with the exception of symbolic, may be used in Virtuoso. Pins can be converted to standard box-wall ports, co-calibrated ports, delta-gap ports or via ports.

For this tutorial, your pins will be converted to standard box-wall ports. For a discussion of the other port types, please see Ports in the Sonnet User's Guide.

You may wish to zoom in on the feed lines of the inductor before adding the pins. To define the ports for your design, do the following:

30.  In the Layers pane on the left side of the layout window, select the “Metal6” layer whose purpose is set to “pin.”

You want to draw the pin on the same drawing layer where you wish to attach the Sonnet port to the metal trace. The metal traces for the inductor are drawn on “Metal6” so we also want to place the pins on Metal6.

31.  Click on the Add Pins button in the Ports section of the Cadence Virtuoso Interface.

The Create Shape Pin dialog box appears on your display.

32.  Enter “P1 P2 P3” in the Terminal Names text entry box.

These names identify the pins. You may enter any character string for the terminal names. We are using P1, P2 and P3 since these pins are going to be converted to Port 1, Port 2, and Port 3 in the translated Sonnet project.

33.  If it is not already selected, click on the “rectangle” radio button for Mode. 

For the best translation of pins into the Sonnet environment, we recommend using a shape pin of the type “rectangle.”

34.  Select the “Create Label” checkbox.

Displaying the pin label in the layout window is optional. For the tutorial, we will display the pin label. Selecting this checkbox allows you to also place a label on the pin when you are adding it in the layout window.

35.  If it is not already selected, select "Manual" from the Create Label drop list.

This allows you to control the appearance and placement of the labels.

36.  Click on the Options button to the right of the Create Label checkbox. 

The Set Pin Label Text Style dialog box appears on your display which allows you to control the appearance of the terminal name in the layout window.

37.  Enter “20” in the Height text entry box.

This ensures that the label is large enough to see in the layout window.

38.  Select the Create as Label checkbox under text options.
39.  Select "Same as Pin" under the Layer Name and Layer Purpose.

This ensures that label appears on the same drawing layer as the pin.

40.  Click on the OK button to close the dialog box and apply the changes.
41.  In the layout window, click on the lower left hand corner of the trace on the left and drag to form a rectangle that overlaps the bottom edge of the trace.

The pin should be placed across the edge of the metal trace to which you wish the Sonnet port attached. It is not necessary to be overly precise in placing your pin; during the translation, the center point of the pin is snapped to the closest available edge of a polygon. Since this pin is located on the edge of your layout, it is converted to a Sonnet box wall port; if the pin had been on the interior of your layout, it would have been converted to a co-calibrated port.

When you complete adding the pin, the label appears.

42.  Click in the layout window where you wish to place the label.

Your circuit should appear similar to the picture below.

43.  In similar fashion, add another pin to the trace on the right.

Your circuit should now appear similar to this:

44.  In similar fashion, add another pin to the trace for the center tap at the top of the inductor.

Your circuit should now appear similar to this:

45.  In the Sonnet Cadence Virtuoso Interface window, click on the “Ports” button.

The Ports dialog box appears on your display.

As you can see, the Cadence pins were automatically mapped to Sonnet standard box-wall ports, since they were placed on the bounding box of the circuit.

46.  Click on the Cancel button to close the Ports dialog box.

Since no changes were made in this dialog box, you may use the Cancel button to close it, ensuring that nothing was changed.

47.  Click on the SonnetEM layout window to select it, then press the ESC key to exit “Create Pin” mode.

The appearance of the cursor changes.

This completes setting up the ports. Next, we will save the changes we have made thus far in the tutorial using the Save State command.

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