HDL Overview and CAD Systems

Questions and Answers

What was a major addition in VHDL-1993 that proved difficult to utilize effectively?

Buffer ports

Shared variables (correct)

Procedural Interface

Protected types

Which version of VHDL introduced protected types?

VHDL-2002

VHDL-2007

VHDL-1993

VHDL-2000 (correct)

What significant change was made in VHDL-2002 regarding buffer ports?

The rules on usage were relaxed. (correct)

They became mandatory for all modules.

They were completely removed.

Usage was restricted to simulation only.

What does VHPI allow in relation to a VHDL model?

Programmable access before and during simulation Signup and view all the answers

How often must VHDL undergo a review process to remain an IEEE standard?

Every 5 years Signup and view all the answers

Which version of VHDL is described as a minor revision of VHDL 2000?

VHDL 2002 Signup and view all the answers

What does HDL stand for?

Hardware Description Language Signup and view all the answers

What was a primary motivation for developing VHDL in 1981?

To address the hardware life cycle crisis Signup and view all the answers

Which of the following is a major CAD system that supports VHDL?

Cadence – Incisive Signup and view all the answers

What is the main purpose of standardization for VHDL as initiated by the DoD?

To encourage investment and industry acceptance Signup and view all the answers

Which organization was given rights to the VHDL language definition to promote its industry use?

IEEE Signup and view all the answers

What does DoD Mil Std 454 mandate for every ASIC delivered to the DoD?

A comprehensive VHDL description Signup and view all the answers

Which of the following HDLs is designed mostly for synthesis and ASIC production?

Synopsis Signup and view all the answers

What was the VHDL baseline language version published before the official standard?

7.2 Signup and view all the answers

Study Notes

Hardware Description Language (HDL)

HDL is used for describing hardware in various contexts such as documentation, simulation, synthesis, and verification.
A Computer-Aided Design (CAD) system is required for utilizing HDL, with major systems supporting VHDL, Verilog, System C, and System Verilog.

Key CAD Systems

Cadence: Offers Incisive for HDL support.
Mentor Graphics: Provides ModelSim and Questa for simulation tasks.
Altera and XILINX: Collaborate to utilize ModelSim in their designs.
Synopsis: Focuses on synthesis and ASIC production from HDL descriptions.

HDL History and Background

The Motivation: Initiated in 1981 by the U.S. Department of Defense to address a crisis in hardware lifecycle management caused by inadequate documentation and inconsistencies in verification tools.
Standardization Process: Early industry participation was encouraged. A baseline version was released two years before the official standard to facilitate tool development. The IEEE was given rights to VHDL to promote broader industrial adoption.

ASIC Requirement

Military Standard: DoD Mil Std 454 mandates VHDL descriptions for every delivered ASIC, reinforcing the use of VHDL throughout the design process for comprehensive documentation.

VHDL Versions and Updates

VHDL 1993: The first significant review under IEEE standards, remains widely supported.
VHDL 2000: Introduced protected types to enhance usability, building upon VHDL 1993 features.
VHDL 2002: A minor revision of VHDL 2000, easing the rules on buffer ports, thus increasing their functionality.

VHPI Introduction

VHDL Procedural Interface (VHPI) is a standard interface that allows seamless communication between VHDL models and simulation tools, facilitating efficient model interactions and enhancing the simulation process.
VHPI (VHDL Procedural Interface): An amendment introduced in 2007 to VHDL 2002, allowing programmable access to VHDL models during simulation, though no major new features were added.

Description

This quiz covers the fundamentals of Hardware Description Languages (HDL), focusing on their applications, including documentation, simulation, and synthesis. It also highlights major CAD systems that support various HDLs such as VHDL and Verilog. Test your knowledge on these essential tools in hardware design!