VHDL Functions and Procedures - 2024.1 English

Vivado Design Suite User Guide: Synthesis (UG901)

Document ID
Release Date
2024.1 English

Use VHDL functions and procedures for blocks that are used multiple times in a design. The content is similar to combinatorial process content

Declare functions and procedures in:

  • The declarative part of an entity
  • An architecture
  • A package

A function or procedure consists of a declarative part and a body. The declarative part specifies:

  • input parameters, which can be unconstrained to a given bound.
  • output and inout parameters (procedures only)
Important: Resolution functions are not supported except the function defined in the IEEE std_logic_1164 package.