Verilog Program Language Interface (PLI) and Verilog Procedural Interface (VPI)

According to "The Principles of Verilog PLI", Programming Language Interface (PLI) is a way to provide Application Program Interface (API) to Verilog HDL. Essentially it is a mechanism to invoke a C function from a Verilog code. The construct which invokes a PLI routine in a Verilog code is usually called a system call. The common system calls built-in to most Verilog simulators are $display, $monitor, $finish etc.

The latest version is PLI 2 or Verilog Procedural Interface (VPI).

The following link shows how to use PLI with VCS:

http://www.sutherland-hdl.com/papers/2002-SNUG-paper_VCS_and_PLI2.0.pdf

A Verilog LPI website

http://www.asic-world.com/verilog/pli.html

give a good tutorial:

Introduction

	How it Works
	Example - Hello World
	C Code Verilog Code Running the Simulation

Writing PLI Application

	PLI Application Specification.
	Calling the C function.
	C Code - Basic
	Verilog Code
	C Code - Full
	Linking With Simulator
	VCS Modelsim
	Counter Simulation Output

PLI Routines.

	Access Routines
	Access Routines Reference
	Program Flow using access routines Handle to Objects Value change link(VCL)
	Utility Routines
	Classification of Utility Routines
	Other Useful functions
	veriusertfs endofcompile_routines err_intercept
	PLI Example
	Clock Generator Clock Generator HDL Wrapper Counter Monitor Counter Monitor HDL Wrapper Counter TestGen Counter TestGen HDL Wrapper HDL TestBench Top Sample : Test File Sample Ouput

Verilog Procedural Interface (VPI)

	Steps : Writing Application Using VPI
	Write a C function Associating C Functions with a New System Task Registering New System Tasks Invoking System Tasks
	Linking with Simulator
	VCS Modelsim NCSim
	VPI Routines