Appendices Table of Contents Appendix A VHDL Primer VHDL Standards History. A-1 IEEE Standard 1076. A-1 IEEE Standard 1164. A-2 IEEE Standard 1076.3 (Numeric Standard). A-2 IEEE Standard 1076.4 (VITAL) . A-3 Learning VHDL . A-3 A Simple Example . A-3 Entity Declarations . A-4 Architecture Declarations . A-5 Data Types. A-6 Design Units . A-7 Levels of Abstraction . A-9 Sample Circuit . A-11 Comparator (Dataflow) . A-11 Barrel Shifter (Entity) . A-14 Signals and Variables . A-18 Using a Procedure . A-18 Structural VHDL. A-20 Design Hierarchy . A-20 Test Benches. A-21 Sample Test Bench . A-22 Conclusion . A-23 Examples Gallery . A-24 Using Type Version Functions . A-24 Design Description. A-24 Test Bench. A-27 Describing a State Machine . A-28 Design Description. A-28 Test Bench. A-31 Reading and Writing from Files . A-33 Design Description. A-34 Test Bench. A-35 Multisim 2001 User Guide i Appendix B.1 Verilog Primer Introduction . .B.1-1 What is Verilog? . B.1-2 What is VeriWell? . B.1-2 Why Use Verilog HDL? . B.1-3 The Verilog Language . .B.1-4 A First Verilog Program . B.1-4 Lexical Conventions . B.1-6 Program Structure . B.1-7 Data Types. B.1-10 Physical Data Types . .B.1-10 Abstract Data Types . .B.1-11 Operators . B.1-12 Binary Arithmetic Operators. .B.1-12 Unary Arithmetic Operators . .B.1-12 Relational Operators . .B.1-12 Logical Operators . .B.1-12 Bitwise Operators . .B.1-13 Unary Reduction Operators . .B.1-13 Other Operators. .B.1-13 Operator Precedence . .B.1-14 2.6 Control Constructs . B.1-14 Selection - if and case Statements . .B.1-15 Repetition - for, while and repeat Statements . .B.1-15 Other Statements . B.1-16 Parameter Statement. .B.1-16 Continuous Assignment. .B.1-16 Blocking and Non-blocking Procedural Assignments . .B.1-16 Tasks and Functions . B.1-17 Timing Control . B.1-19 Delay Control ( #). .B.1-20 Events . .B.1-20 wait Statement . .B.1-21 fork and join Statements . .B.1-21 Traffic Light Example . .B.1-22 Using the VeriWell Simulator . .B.1-24 Creating the Model File . B.1-24 Starting the Simulator. B.1-24 ii Electronics Workbench How to Exit the Simulator? . ..