Cadence Tools Lab Manual
CADENCE TOOLS BASICS:
STARTING AND STOPPING CADENCE
CELLS AND VIEWS
CREATING NEW CELLS
STARTING AND STOPPING CADENCE
To run any of the Cadence tools run the following commands:
The Cadence Command Information (CIW) Window will open. This window allows
you to access all of your Cadence files and to start all of the Cadence
Command Information Window
IMPORTANT: To quit working in Cadence, you MUST:
Close all Cadence windows except the CIW window by selecting Window...Close
or File...Quit from the window menu.
Do NOT close the windows using the Xwindow
option available on the frame of each window!
Only when all other windows have been closed:
Close the CIW window by selecting File...Exit from the menu.
LIBRARY MANAGER [TOP]
Libraries are organizational units that contain the various gates, schematics,
and other design units that you will be working with. The Library Manager
tool is used to manage libraries. To start it, select
Manager in the Log Window. The Library Manager window will open.
Library Manager Window
The Library Manager Window shows the libraries that are available
to you. You will use the ece322 library for all of the labs. Components
will be added to the ece322 library as needed for your labs and projects.
The ece322 library is based on the HP.35u library, which is also listed
in the Library Manager Window. The basic library contains pins and other
primitives and the cdsDefTechLib library is placeholder for other internal
You will only be using components from the ece 322 library and any libraries
that you create yourself. You should create a new library for each of your
labs and projects.
CREATING LIBRARIES [TOP]
Select File...New...Library from the Library Manager menu. The New
Library window will open:
Enter the name of the library you wish to create in the name box.
Make sure the directory is <your home directory>/cds/cdslib
and that No DM is selected in the Design Manager frame.
In the example shown, a library named lab1 is being created
in the directory /home/blevine/cds/cdslib. (Note: The home directory
is /home/blevine; your home directories will look like /afs/ece/usr/blevine.)
In the Technology File for New Library window that will open, select either
Attach to an existing techfile or Don't need a techfile as
instructed in the specific lab, and click OK.
CELLS AND VIEWS [TOP]
Cadence libraries contain components, such as gates and transistors.
Each component is called a cell. A cell can have multiple cell views. These
cell views represent different ways that the component can be represented.
For example, a NMOS transistor can be represented as a symbol to be used
in a schematic, as a simple switch level Verilog behavioral model, or as
an analog SPICE model. In the example below, the Library Manager tool is
used to show all of the cell views for the cell called nfet in
the ece322 library. There is currently a symbol view
and a verilog view. Views can be added to cells, just as
cells can be added to libraries. Understanding this hierarchical
structure is important to avoid confusion when using the Cadence tools.
CREATING NEW CELLS [TOP]
To create a new cell (component in your library), you actually create
a view for the cell. To create a new cell:
Select File...New...Cell View from the Library Manager menu or to
the Cadence Information Window menu. The Create New FIle window will open:
Select the name of the library you wish to add your cell to in the Library
Enter a name for the cell in the Cell Name box.
Different Cadence tools are used to create different types of Cell Views.
Choose the tool you will use to create the cell from the Tool list according
to the instructions you are given in the specific lab. The View Name box
will be automatically filled in based on your choice in the Tool list.
In the example above, the Composer - Schematic tool is selected,
and Schematic was automatically filled placed the View Name
Verify that the Library path file is <your home directory>/cds/cds.lib.
OPENING FILES [TOP]
To open an existing file, got to the Command information Window and select
from the menu. The Open File window will appear.
FIrst you must specify the library by selecting it from the Library Name
list. A list of the cells in that library will appear in the Cell
Names box. You can choose the cell by selecting it from the list or by
typing the name in the Call Name box.
Once you have selected the cell, you can choose the view you wish to work
with by selecting it from the View Name list. Only those views available
for the cell you have selected will appear in this list.
The default mode for opening the cell view is Edit mode, but you can select
Read instead, if you wish to open a read-only copy.
Click OK. The cell view you select will open in the appropriate
tools for that view. (i.e., Composer for schematics, Virtuoso for layouts,
1999 Carnegie Mellon University