Verilog-A
Language Reference Manual
Analog Extensions to Verilog HDL
Version 1.0
August 1, 1996
Open Verilog International
No part of this work covered by the copyright hereon may be reproduced or used in any form or by any means --
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Additional copies of this manual may be purchased by contacting Open Verilog International at the address
shown below.
Notices
The information contained in this draft manual represents the definition of the Verilog-A hardware description
language as proposed by OVI (Analog TSC) as of January, 1996. Open Verilog International makes no warran-
ties whatsoever with respect to the completeness, accuracy, or applicability of the information in this draft man-
ual to a user’s requirements. This language is not yet fully defined and is subject to change. It is suitable for
learning how to do analog modeling and as a vehicle for providing feedback to the standards committee. Verilog-
A should not be used for production design and development.
Open Verilog International reserves the right to make changes to the Verilog-A hardware description language
and this manual at any time without notice.
Open Verilog International does not endorse any particular simulator or other CAE tool that is based on the Ver-
ilog-A hardware description language.
Suggestions for improvements to the Verilog hardware description language and/or to this manual are welcome.
They should be sent to the address below.
Information about Open Verilog International and membership enrollment can be obtained by inquiring at the
address below.
Published as: Verilog-A Language Reference Manual
Version 1.0, August 1, 1996.
Published by: Open Verilog International
15466 Los Gatos Blvd., #109071
Los Gatos, CA 95032
Phone: (408) 358-9510
Fax: (408) 358-3910
Printed in the United States of America.
Verilog
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is a registered trademark of Cadence Design Systems, Inc.
The following people contributed to the creation, editing and review of this document.
Ramana Aisola Motorola aisola@analog-dse.sps.mot.com
Kevin Cameron Meta-Software kevinc@metasw.com
Dan FitzPatrick Apteq dkf@apteq.com
Vassilios Gerousis Motorola gerousis@chdasic.sps.mot.com
Ian Getreu Analogy iang@analogy.com
Kim Hailey Meta Software kimh@metasw.com
Ken Kundert Cadence kundert@cadence.com
Oskar Leuthold GEC Plessy leuthold@sv.gpsemi.com
S. Peter Liebmann Meta Software peterl@metasw.com
Ira Miller Motorola miller@analog-dse.sps.mot.com
Tom Reeder Viewlogic treeder@viewlogic.com
Steffen Rochel Anacad/Mentor steffen_rochel@mentorg.com
James Spoto Cadence spoto@cadence.com
Richard Trihy Cadence trihy@cadence.com
Yatin Trivedi SEVA Technologies trivedi@seva.com
Alex Zamfirescu Veribest a.zamfirescu@ieee.org
Version 1.0 Verilog-A Language Reference Manual v
Table of Contents
Verilog-A HDL Overview
Overview ........................................................................................... 1-1
Systems ............................................................................................. 1-1
Conservative systems .................................................................. 1-2
Kirchhoff’s laws .......................................................................... 1-3
Signal-flow systems .................................................................... 1-4
Mixed systems ............................................................................ 1-5
Natures, disciplines and nodes .................................................... 1-7
Conventions used in this document .................................................. 1-8
Contents ............................................................................................ 1-9
Lexical Tokens
Lexical tokens ................................................................................... 2-1
White space ....................................................................................... 2-1
Comments ......................................................................................... 2-1
Operators ........................................................................................... 2-2
Numbers ............................................................................................ 2-2
Integer constants ......................................................................... 2-2
Real constants ............................................................................. 2-3
Units for real constants ............................................................... 2-4
Conversion .................................................................................. 2-4
Identifiers, keywords, and system names ......................................... 2-5
Escaped identifiers ...................................................................... 2-5
Keywords .................................................................................... 2-5