Identify Cells by Truth Table

This tutorial will show you how to automatically identify a cell. You will learn how to create a cell and how to use the cell identifier.

Creating the Cell

  1. In the Layers window, turn on the m1 image layer.

    layers1

  2. In the Project Cells window, click the down arrow on dig block, block 0 array, and then buf. Then, click the down arrow in the window that moves the user into the target netlist.

    projectcell

  3. Remove the old cell. In the Project Cells window, right-click on BUF (430), and choose Delete BUF.

    deletecell1

  4. Go to the Cells tab and click Add Cell.

    addcell

  5. Click-and-drag to add a new cell and a window like this will appear:

    addcellwindow

  6. Make sure that Automatic ports are turned off and then press add four times

  7. Next, name the ports A, B, C, and D, and their types as VDD, VSS, input, and output, respectfully.

  8. Click create cell.

  9. Make sure that once the cell is created, in project manager the cell visibility button has show port names checked.

  10. Now, move A, B, C, and D into the following spots:

abcd

Creating the Netlist

  1. Open the Netlist tab click Create Netlist.

    createnetlist

  2. In the Create Netlist window click M2, M1, Polysilicon, N-Diff Active, and P-Diff Active to include all layers in this cell.

    createnetlistlayers1

  3. Click Create to have the software generate the netlist for this cell.

Identifying a Cell

  1. In the Netlist tab, click the Find Transistors button then Find. This process will identify and place all of the transistors.

    findtransistors

  2. Now make sure that everything looks good. Press Show Schematic and a window like this should appear:

schematics

  1. After the transistors have been placed the software can browse the reference library to see if an instance of this cell has already been cataloged. To do this click Identify by Truth Table.

    identifycell1

  2. If the cell found a match a window will pop out giving you the option to keep the cell name, ports and the schematic image identical to the instance in the reference library. Click on the first BUF and then press the green checkmark to confirm, then press copy.

    results1

  3. The user will see that the Pix2Net changed the cell to what it should be officially identified as

end

  1. Go to the File tab and click Backup Manager. Restore the backup of the project to undo your changes.