Copyright © 2004 IEEE. All rights reserved. v
Contents
1. Overview.............................................................................................................................................. 1
1.1 Objectives of this standard......................................................................................................... 1
1.2 Conventions used in this standard.............................................................................................. 1
1.3 Syntactic description.................................................................................................................. 2
1.4 Contents of this standard............................................................................................................ 2
1.5 Header file listings..................................................................................................................... 4
1.6 Examples.................................................................................................................................... 5
1.7 Prerequisites............................................................................................................................... 5
2. Lexical conventions ............................................................................................................................. 6
2.1 Lexical tokens............................................................................................................................ 6
2.2 White space................................................................................................................................ 6
2.3 Comments .................................................................................................................................. 6
2.4 Operators.................................................................................................................................... 6
2.5 Numbers..................................................................................................................................... 6
2.5.1 Integer constants ........................................................................................................... 7
2.5.2 Real constants ............................................................................................................. 10
2.5.3 Conversion.................................................................................................................. 10
2.6 Strings ...................................................................................................................................... 11
2.6.1 String variable declaration.......................................................................................... 11
2.6.2 String manipulation..................................................................................................... 11
2.6.3 Special characters in strings........................................................................................ 11
2.7 Identifiers, keywords, and system names ................................................................................ 12
2.7.1 Escaped identifiers...................................................................................................... 12
2.7.2 Generated identifiers................................................................................................... 13
2.7.3 Keywords.................................................................................................................... 13
2.7.4 System tasks and functions......................................................................................... 13
2.7.5 Compiler directives..................................................................................................... 14
2.8 Attributes.................................................................................................................................. 14
2.8.1 Examples..................................................................................................................... 15
2.8.2 Syntax ......................................................................................................................... 16
3. Data types........................................................................................................................................... 19
3.1 Value set................................................................................................................................... 19
3.2 Nets and variables.................................................................................................................... 19
3.2.1 Net declarations ..........................................................................................................19
3.2.2 Variable declarations .................................................................................................. 21
3.3 Vectors..................................................................................................................................... 22
3.3.1 Specifying vectors....................................................................................................... 22
3.3.2 Vector net accessibility............................................................................................... 23
3.4 Strengths .................................................................................................................................. 23
3.4.1 Charge strength...........................................................................................................23
3.4.2 Drive strength.............................................................................................................. 23
3.5 Implicit declarations................................................................................................................. 24
3.6 Net initialization....................................................................................................................... 24
3.7 Net types .................................................................................................................................. 24
3.7.1 Wire and tri nets.......................................................................................................... 24
3.7.2 Wired nets................................................................................................................... 25