Schematic Edit

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

Part I. Create a new library
Part II. Create a new schematic cell view
Part III. Placing a instance to a schematic editing window
Part IV. Some basic skills in manipulating the symbols
Part V. List of required properties.

Part I. Create a new library:

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

Part II. Create a new schematic 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 for the new cell ("Cell Name" field) and its type of view - schematic ("Cell View" field). Click Ok. A Composer - Schematic Editing window will appear.

The window titled Composer - Schematic Editing indicates this is a schematic-editing window.
There is a menu bar and an icon bar. The most basic icons that we are going to use to build a schematic are Instance, Property, Wire (narrow), and Save.
Now you are ready to create your MEMS schematic.

Part III. Placing an instance in the schematic editing window

1. Click on the new instance icon on the left hand side of schematic window

 

2. In the add instance dialog, click Browse and select the instance you need from the library dialog window that pops up. Or you can input the needed library and needed instance (for example, put NODAS_HP as library, and beam_0010 as instance)



3. Enter the corresponding properties at the bottom of the add instance window (for example, put 100u into property l; 2u into property w, 0 into property angle).
4. If needed click once on the Rotate button to rotate the instance to a vertical position
5. Left click anywhere in schematic window to place  the instance

   

Part IV. Some basic skills in manipulating the instances

1. Move an instance around

- point to the symbol with the cursor, click on and hold the left mouse button, drag the instance to any location, and release the button. This skill is useful when you want to connect two components together.

2. Wire instances (basic)
• click on wire icon
  
  now you are in wire mode
• click on connection A, then click on connection B
  
  a wire will be automatically placed between connection A and connection B

  Note: press "Esc" to escape wire mode, when you are done wiring.

3. Remove a misplaced instance or wire

- Left click the wire or instance to be deleted, once it is highlighted press the delete key.

Note: press Esc key to get out of delete mode. To undo click Edit =>Undo in the schematic window.

4. Wire instances (advanced)
• To wire two instances together drag one instance so that its wiring pins overlap the wiring pins of the second instance exactly (i. e. x to x, phi to phi).
  

=>

• This step will establish wire connections between the overlapping pins. Now the instances can be moved apart by dragging either instance away from the other.




5. Change the properties of an instance


The properties (length, width... etc) of an instance can be changed by middle clicking on the instance and selecting "Properties" from the pop-up menu. Change the properties as needed, then click OK.



6. Rotate an instance


A vertical beam can be obtained by rotating the default horizontal beam instance by 90 degrees. Rotation can be done by selecting the component and clicking on the right mouse button and then selecting a reference point to rotate around.

Note: Remember after you rotate a instance, you have to change the value of the "angle" property to 90 by clicking on the middle mouse button and selecting "Properties...". At present, only rotation of beam within range 0^o to 90^o is allowed by keeping node b as rotation origin.




7. Zoom in or zoom out schematic view
• The view size of an instance can not be changed. They can only be adjusted by using the zoom in and out icons from left of the schematic window
  
  Therefore, in order to to be able to fit all the components into to your circuit, you need to adjust the distance between instances.
• Another way to zoom in is to drag the mouse with right mouse button pressed.
8. Don't forget to save once in a while! Just click on the save button.

Part V. Cadence library Help

1. find out the list of instances
2. find out required properties of each instance
   

After you done editing your design schematic, save it, and next step is to do Simulate.

Updated March 8, 2000 by Kai He at khe@ece.cmu.edu