University
of Rhode Island Department of Electrical and Computer Engineering
University
of Rhode Island
Department of Electrical and Computer Engineering
Section 3: Mentor Graphics Layout vs. Schematic Tutorial
In this section we will demonstrate the use of Layout vs Schematic (LVS).
LVS is a tool in IC Station that links an IC layout to a Design Architect schematic
sheet. You will need to use both the schematic that you created in Section 1 and the layout that you created in Section 2.
1) Invoke Design Manager.
First we need to invoke Design Manager. From a command prompt at your home directory, type the command "dmgr" without the quotations. This will invoke Mentor Graphics' Design Manager.
2) Create a design viewpoint (DVE)
- Use the DVE button in Design Manager's Tools window to start DVE, the Design Viewpoint Editor.
- Use the "OPEN VPT" button to create a new viewpoint. Use the navigator button on the Open Viewpoint dialog box to choose the ~/LVDTutorial/inv/schematic/inv_sheet file. This file contains the transistor level logic for a CMOS inverter. Click OK. The Component Name text box will be filled in with the path to the inv directory, and the Viewpoint Name will be "Default." Click OK.
- The viewpoint has now been created. Save the viewpoint with the File > Save Design Viewpoint > With Same Name menu item. Exit the DV Editor.
3) Use IC Station and LVS to link the Layout to the Schematic
- From the Design Manager, start the IC Station tool by clicking on the "IC" button in the tools menu.
- The inverter layout has already been created. Choose the Cell - Open button from the Palette to open the "inv_cell_lvs" file. Make sure that you open the cell in Edit Mode (the default is read-only).
- On the IC Palette, choose "ICTrace (M)", then LVS. The LVS dialog box will appear. For the source name, use navigator to choose the viewpoint that you created (~/LVSTutorial/inv/default) and click OK. This will start an LVS run.
- When LVS has finished, choose Report >LVS from the Palette. In the window that appears, you should see a check mark and a smiley-face, indicating that the LVS run was successful.
- Now the Layout and the Schematic are linked. From the Palette, choose Open > logic: A window with the schematic diagram will appear. Arrange the two windows so that both the schematic and the layout are visible on the desktop. The two diagrams are linked. If you select the input port on the schematic, then the input port on the layout will also be highlighted (see image below). This is also true for the output, VCC and ground ports.
That's all for Section 3
Go on to Section 4: Accusim
Mentor Graphics Tutorial Home Page
created by Seth Milman, 6/19/98
last update: 7/2/98