16. Introduction to User Defined Primitives
 

User Defined Primitives (UDPs) are custom primitive components defined using truth tables or state tables. They provide a simple, table-based approach to defining basic logic gates and sequential elements without using behavioral or structural Verilog code.
 

What are UDPs?
 

UDPs are user-defined building blocks that:
 

• Define custom primitives using tables instead of code
   

• Are simpler than modules for basic logic
   

• Have exactly ONE output (first port)
   

• Can be combinational or sequential
   

• Are fully synthesizable
   

Why Use UDPs?
 

• Simplicity: Table-based definition is intuitive
   

• Efficiency: Compact representation of logic
   

• Clarity: Truth/state tables are self-documenting
   

• Reusability: Define once, instantiate many times
   

• Synthesis: Directly maps to gates
   

Types of UDPs