Virtuoso Schematic Composer Tutorial

1 Virtuoso Schematic Composer TutorialProduct Version 2003 1991-2003 Cadence Design Systems, Inc. All rights in the United States of Design Systems, Inc., 555 River Oaks Parkway, San Jose, CA 95134, USAT rademarks:Trademarks and service marks of Cadence Design Systems, Inc. (Cadence) contained inthis document are attributed to Cadence with the appropriate symbol. For queries regarding Cadence strademarks, contact the corporate legal department at the address shown above or call other trademarks are the property of their respective Print Permission:This publication is protected by copyright and any unauthorized use of thispublication may violate copyright, trademark, and other laws.

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4 Or its Schematic Composer TutorialJune 20033 Product Version .. 7 Related Documents .. 8 Typographic and Syntax Conventions .. 81 Installing the Tutorial Database .. 11 Prerequisites ..11 Overview of the Installation Process .. 11 Your Working Environment .. 12 Copying the Installation Script .. 12 Running the Installation Script .. 13 Copying and Editing the Dot Files .. 14 Copying the System-Specific Dot Files .. 14 Editing the .cshrc File .. 14 Copying the Environment Dot File .. 16 Starting the Schematic Composer Software .. 16 Setting the Paths to the Libraries .. 182 Getting Started with Schematic Composer .. 21 About the Tutorial Libraries, Cells, and Cellviews.

5 21 Setting Options ..23 Opening the Schematic Window .. 24 Viewing the Schematic .. 26 Browsing the Schematic Hierarchy .. 28 Moving Down the Schematic Hierarchy .. 29 Moving Up the Schematic Hierarchy .. 30 Closing the Design and Quitting the Software .. 31 ContentsVirtuoso Schematic Composer TutorialJune 20034 Product Version Symbols and Pins.. 33 Creating a New Design .. 34 Opening the top_level Design.. 34 Placing the ALU Symbol .. 35 Creating the One s Complement Symbol .. 37 Creating the Accumulator Symbol .. 40 Placing the Accumulator Symbol .. 41 Placing the One s Complement Symbol .. 43 Adding the Schematic Input and Output Pins.

6 44 Adding the DEC Bus .. 47 Adding the Output Bus .. 514 Adding Wires, Checking the Schematic , and Attaching aBorder.. 53 Wiring the Input Pins .. 53 Wiring the ALU .. 56 Naming the Nets .. 58 Placing the Input Wire Names .. 60 Placing the Output Wire Names .. 61 Checking the Schematic .. 62 Setting Up the Check Rules .. 63 Running Check and Save .. 64 Identifying the Errors .. 66 Naming the DEC Bus .. 69 Creating a Sheet Border and Title .. 70 Creating a Border .. 70 Centering the Schematic within the Border .. 71 Adding a Name to the Title Block .. 73 Virtuoso Schematic Composer TutorialJune 20035 Product Version the Accumulator Schematic .

7 77 About the Accumulator .. 77 Adding Instances .. 78 Adding Two 4-Bit Adder Symbols .. 80 Adding the 8-Bit Register Symbol .. 82 Adding Power and Ground Symbols .. 83 Adding Wires and Buses .. 85 Stretching the Register Symbol .. 85 Wiring the Adders, Power Supply, and Ground Symbols .. 87 Moving the Schematic Pins for Space .. 90 Drawing the Buses .. 91 Wiring the CLK Pin .. 92 Wiring the Adders .. 93 Wiring the Register .. 96 Naming the Nets .. 97 Naming the Nets That Tap the B Bus .. 97 Naming the Nets That Tap the Y Bus .. 103 Checking the Schematic .. 1036 Creating the Analog Amplifier Schematic .. 105 About the Analog Amplifier Schematic .

8 106 Creating the amp Schematic Cellview .. 106 Adding Symbols for the Four Resistors .. 107 Changing Resistor Parameter Values .. 109 Adding a Capacitor and Changing Its Parameter Values .. 111 Adding Symbols for the Power and Ground .. 112 Adding the Transistor Symbol .. 113 Adding the I/O Pins .. 115 Aligning the Symbols .. 116 Wiring the Schematic .. 118 Cleaning Up the Schematic .. 119 Adding CDF Data .. 121 Virtuoso Schematic Composer TutorialJune 20036 Product Version a Symbol from a Schematic .. 1257 Preparing the top_level Schematic for Simulation.. 129 Adding the ones_comp Circuit .. 129 Finishing the top_level Schematic .

9 130 ASolving Problems .. 133 Virtuoso Schematic Composer TutorialJune 20037 Product Version Virtuoso Schematic Composer is a design entry tool that supports the work of logic andcircuit design engineers. Physical layout designers and printed circuit board designers canuse the information as background material to support their preface discusses the following: Related Documents on page 8 Typographic and Syntax Conventions on page 8 Virtuoso Schematic Composer TutorialPrefaceJune 20038 Product Version DocumentsThe Schematic Composer is often used with other Cadence products or requires knowledgeof special languages such as the Cadence SKILL language. The following documents giveyou more information about these tools and languages, but in general for this Tutorial , you willnot need to refer to them.

10 TheDesignFrameworkIIUserGuideprovides information if you are not familiar withCadence terms and starting your system. TheCadenceApplicationInfrastructureUserG uideprovides additional informationabout the architecture. TheVirtuosoSchematicComposerUserGuidedes cribes how to create and checkschematics and symbols. TheInherited Connections Flow Guide describes how to use inherited connectionsand net expressions with various Cadence tools in the design flow. TheVirtuoso Schematic Composer SKILL Functions Reference is for users whocustomize the standard product. TheLibrary Manager User Guide explains how to open or create cellviews from theLibrary Manager. TheVerilog-XL Integration for Schematic Composer Reference and theVerilog-XL Integration for Schematic Composer User Guide describe how to use theschematic Composer with Verilog HDL.