The tools used in this tutorial are Cadence Virtuoso IC 23.1 and Spectre 23.1 ISR1.

• .cdsinit, .cdsenv, .cadence directory.

• CIW (Command Interpreter Window) to access the design – Toolbar manager and Library manager.

CIW: The design environment interface used to access many Virtuoso applications.

Library: A collection of design cells represented by cell views.

Library Manager: A Cadence tool to manage design library.

Cell: A basic unit of a design hierarchy described by cell views.

Cell view: A specific view of a cell (schematic, symbol, text or layout)

Instance: A uniquely named placement of a cell symbol onto a schematic.

Bindkey: A predefined key on the keyboard that applies a pre-selected command.

Virtuoso provides a single integrated environment for accessing all the tools and design data.

• To start virtuoso, in the terminal type: virtuoso

• CIW can be customised using the 'User Preferences' form.

Library Manager is used to browse design files, and create new libraries, cells and cellviews. Here you can start or edit a schematic view or symbol view, start or edit a layout design, run layout verification, start Virtuoso ADE and run simulations, access the simulation results directly with the Results Browser and Virtuoso Visualisation and Analysis tool, and run OCEAN script (a way to run Virtuoso without the GUI by invoking scripts).

Backannotation: Data can be backannotated from:

• Layout to Schematic

• Simulation to Schematic

• Simulation to Layout

Certain configurations are required for Virtuoso Design Environment to start. Therefore it is important to launch the Virtuoso tool (using virtuoso command)only when present in the the directly with the following configuration files/directory: cds.lib, .cdsinit, .cdsenv, .cadence.

File Descriptions:

Note that, it is highly advisable to not edit any of these files directly, and instead use the CIW GUI to make the additions/deletions/modifications.

1. cds.lib : Cadence library setup file. It contains the essential library paths from the software hierarchy. You can also include the user-defined libraries in the cds.lib file. The library manager lists the libraries present in the cds.lib file – and can be edited using the GUI tool.
   Supported Keywords: SOFTDEFINE, SOFTINCLUDE, DEFINE, UNDEFINE, ASSIGN, and UNASSIGN.

2. .cdsinit : These are the cadence initialisation files set environment variables containing user or site SKILL code definitions. When Cadence launches the tool, it reads the .cdsinit file to set up your configurations.
   Environment variables are set by calling the schsetEnv or envSetVal in the cdsinit file.