EETimes (7/19/2011 10:35 PM EDT)
Editor’s Note: In this series of articles based on his book – Design Recipes for FPGAs – Peter Wilson provides a basic quick overview of VHDL (VHSIC hardware description language) followed by examples of its use in describing - in HDL code form - functions familiar to most embedded software developers such as arithmetic logic units (ALUs) and finite state machines (FSMs). It is not intended as a comprehensive VHDL reference. For that, he recommends “Digital System Design with VHDL,” by Mark Zwolinski; ”VHDL: Analysis and modeling of digital systems,” by Zainalabedin Navabi or “Designer’s Guide to VHDL” by Peter Ashenden.
In hierarchical designs, functions are a simple way of encapsulating behavior in a model that can be reused in multiple architectures. Functions can be defined locally to an architecture or more commonly in a package.
Click here to read more ...