Layout Edit

The instructions below assume you have set up and started Cadence properly.

Part I. Create a new library
Part II. Create a new layout cell view
Part III. Placing a rectangle to a layout editing window
Part IV. Some basic skills in manipulating the layouts

Part I. Create a new library:

1. You will need a Cadence HP design library. Please refer to Cadence start up on how to create a new library.

Part II. Create a new layout cell view:

1. From the "Library Manager" window chose File => New => Cell View



Note: the area circled by red indicate user input.

2. Enter a name of the new cell ("Cell Name" field) and its type of view - layout ("Cell View" field). Click Ok. Two windows will appear. One is the LSW (Layer Selection Window). The other is the Virtuoso Editing window (main window for editing your layout).

The window titled LSW indicates this is a layer selection window.
The window titled Virtuoso Editing indicates this is a layout-editing window. There is a menu bar and an icon bar in the Virtuoso Editing Window. The most basic icons that we are going to use to build layouts are Rectangle, Stretch, Move, Save.
Now you are ready to create your layout.

Part III. Drawing a METAL3 rectangle in a layout editing window

1. Click on the metal3 icon on LSW window.
   
   On the top of LSW, you can see that the current working layer is set to METAL3.
   
2. Click on the rectangle icon on the left hand side of layout editing window

 

3. Now you are in rectangle drawing mode. Click the left mouse button once in the place you want to start your rectangle. Click again in the place you want to end the rectangle.
   
4. Rectangles form the basic unit of layout. You can select other layers in LSW and draw different rectangles with these layers the same way you did with METAL3.

Part IV. Some basics in manipulating designs

1. Move a rectangle around

- Highlight the symbol you want to move by left clicking it once. Now you can you move the rectangle around by left clicking and holding the mouse button. Move the rectangle to a new location and release the mouse button.

2. Stretch a rectangle
• click on the stretch icon
  
  now you are in stretch mode
• Now move your mouse over the edge of a rectangle that you want to stretch. You will notice that edge becomes highlighted.
  
  left click the mouse to select that edge, then stretch that edge by moving the mouse.
  

  Finalize the stretch by left clicking the mouse in the location you want the edge to stay.
  
  

3. Remove a misplaced rectangle

- select the rectangle by left clicking on it, the rectangle will become highlighted. Press the delete key from the keyboard

Note: press the Esc key to escape delete mode when you are done. To undo deleting, click Edit =>Undo in the schematic window.

4. Zoom in or zoom out layout view
• The view size of an instance can not be changed. It can only be adjusted by using the zoom in and out icons from left side of the schematic window
  n
  Therefore, in order to fit all the components into to your circuit, you need to adjust the distance between the instances appropriately.
• Another way to zoom in is to drag the mouse with right mouse button held. This will zoom into the area created by the square
5. Don't forget to save once in a while! Just click the save button.

Updated April 10, 2000 by Kai He at khe@ece.cmu.edu