The MACRO Preprocessor 
This Help is actually a tutorial rather than a reference
document. Read the topics in the following order.
Macro Processor Overview
A Simple Macro Definition
A More Complicated Example
Accessing The Argument List
Generating Net Names
Function Calls
Generating Partial FHDL Statements
The else-if Construct
Accessing Attributes
Arithmetic and Logical Expressions
String Handling Functions
List Handling Features
Type Conversion Functions
Redirecting Output
Creating Macro Libraries
Including Text
A Word on Format
Executing the Preprocessor
Macro Statement Summary
Macro Processor Keywords
Macro Operator Precedence