cadence教程

1 Cadence Tutorial

I. Introduction This tutorial provides an introduction to analog circuit design and simulation with Cadence, and covers the features that are relevant for the homework assignments. The tutorial is divided into the following topics:

• Logging on and Starting Cadence

• Creating a Design

o Creating a new library and cellview o Placing the Parts o Editing the Symbol Properties o Wiring the Schematic o Modifying Wire Attributes

• Analyzing the Design and Plotting Results

o Finding the DC Operating Point and performing a DC Sweep o Performing a Transient Analysis o Performing an AC Analysis o Performing a Parametric Sweep o A Note on Measuring Currents o A Note on Plotting

• Invoking Cadence Help

o Getting Additional Help with Cadence Throughout the document, the following II. Logging on and Starting Cadence

In order to use the ECE164-provided installation of Cadence, you either need to be sitting at one of the Linux workstations provided for use by ECE264 students (see the ECE264 website for the locations of these workstations), or you can login remotely to ieng6-203.ucsd.edu. In either case, you should login with your Open Computing Environment account obtained via Academic Computing Services (ACS). If you wish to login remotely, you will need SSH and X-server software on your local machine. The necessary software is available as part of the operating systems on Sun Workstations, PCs running Linux, and Macintosh computers running OS X. It can be obtained via third parties for computers running Windows. Students who wish to login remotely are responsible for obtaining (if running Windows), learning how to use, and maintaining their own SSH and X-server software. Once you have logged in, open a terminal window if one does not open automatically and type the following in the window: ee264a cd ece-cadence icfb &

A window containing text should appear at the bottom of the screen, labeled “icfb -

...”. This is sometimes called the CIW (Command Interpreter Window). A window explaining new

features should also come up; in this window, select “Edit > Off at Startup”, and

then close it. The CIW window is the main Cadence window, and much useful information is displayed here. If Cadence isn’t doing what you expect, it is often helpful to look here to read the error messages. You may find it helpful to enlarge the window. You now need to bring up the library manager. To do this, select “Tools > Library

Manager” in the CIW. A “Library Manager” window appears. Notice the library “ece264lib”. 2 This library contains most if not all of the IC components (e.g., transistors, resistors, etc.) that will be used in this class. II. Creating a Design

The creation of a simple transistor amplifier is described in this section. The following

notational conventions are used in the description:

• The text “[LIB]” should be replaced with “164” if you are taking ECE164 and by “264” if you are taking ECE264.

• Bracketed letters such as “[a]” denote keyboard shortcuts (bindkeys) which can be used instead of the menus or buttons to accomplish the given task. To use them, place the pointer over the appropriate window and simply press the key. Please note that these bindkeys are case sensitive.

For letters enclosed by square brackets such as “[a]”, the pointer must be in a schematic window. For letters enclosed by curly brackets such as “{a}”, the pointer must be in a waveform window. A

summary of the most useful bindkeys is listed in Appendix A. Creating a new library and cellview

1. Create a new library named “tutorial”: (a) In the CIW, select “File > New > Library”, and a “New Library” window

will appear. (b) In the “Name” field, enter “tutorial”. (c) Verify that the path (near the bottom of the dialog box) points to your working directory (or wherever you’d like to place all your class libraries). This path will by default point to the directory from which you invoked Cadence (d) Select the “Don't need a techfile” button, then click “OK”. In the Library

Manager, an entry “tutorial” should appear.

2. Create a new schematic cellview in our new library. (a) In the CIW, select “File > New > Cellview...”, and a “Create New File” dialog box appears.

(b) Ensure that the “tutorial” is selected for Library Name (by clicking on the square

button).

Type “tutorial” in the “Cell Name” field as well. (c) Type “schematic” in the “View Name” field. (d) Select “Composer - Schematic” in the “Tool” field if it is not already selected,

then click “OK”. An empty schematic window appears. (e) In the schematic window, select “Design > Save”. You have now successfully