FO4 INV Example

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  1. This assumes that you have a cell (inv in this tutorial) that has a schematic and layout. It is also DRC clean and passes LVS.
  2. In your schematic view, create a symbol of your design under test (inverter in this case). Design->Create Cellview->From Cellview. The defaults should be correct, but you want to convert from schematic to a symbol view. The Tool/Data Type should be Composer-Symbol.
  3. Create a "inv_test" schematic and layout. In the schematic, you can place your inverter component with Add->Instance and selecting your library and inverter in the component browser. In the layout, you can place an instance of your own cell by doing a Create->Instance... and putting your library name and your cell name in the correct fields. It will then look something like this:
    Fo4 test.jpg
  4. This is simply an inverter with an fanout of 4 identical inverters. If you add the metal and vias to connect the inverters on metal2, the inv_test layout looks like this when viewing only the top level (via Display->Options). I also added input, output, and vdd/gnd ports at this level too. Make sure the FO4 schematic and layout pass DRC and LVS.
    Layout setup hierarchy.jpg
  5. Refer to Simulation Tutorial on how to simulate the above circuit.