VESA^® = = VSIS^™ Standard;

Video Electronics Standards Association = &nb= sp; = &nb= sp; = &nb= sp;

860 Hillview Court, Suite 150 = &nb= sp; = &nb= sp; = Phone: 408-957-9270

Milpitas<= /span>, CA 95035 &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp; = Fax: 408-957-9277

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Video Signal Standard (VSIS) <= /b>

Version 1, Rev. 2

December 12, 2002

Purpose=

To establish the stan= dard analog video signal characteristics for today’s graphics cards and display monitors.

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Summary=

To date, the graphics= controller output signals that drive the display monitor have not been well defined. H= and V sync signals are defined only as TTL. The display side has the same probl= em, as each design may have been optimized to correct for certain signal deficiencies from particular graphics controllers. This document will lay t= he groundwork that both graphics controller and monitor designers can use to achieve compatible designs.

Intellectual Property;

© Copyright 1= 999 - 2002 - Video Electronics Standards Association. All rights reserved.

While every precaution has been taken in the preparation of this standard, the Video Electronics Standards Association a= nd its contributors assume no responsibility for errors or omissions, and make= no warranties, expressed or implied, of functionality or suitability for any purpose.Trademark= s;

All trademarks used within this document are= the property of their respective owners.

• VESA is a trademark of the Video Electronics Standards Association.

Patents;

VESA proposals and standards documents are adopted by the Video Electronics Standards Association without regard as to whether their adoption may involve patents or articles, materials, or processes. Such adoption does= not assume any liability to any patent owner, nor does it assume any obligation whatsoever to parties adopting the proposal or standards documents.

Support for this Standard;

Clarifications and application notes to supp= ort this standard may be written. To obtain the latest standard and any support documentation, contact VESA.

If you have a product that incorporates the Video Signal Standard, you should ask the company that manufactured your product for assistance. If you are a manufacturer, VESA can assist you with clarification. All comments or reported errors should be submitted in writing to VESA using one of the following methods:

= · Fax:         = 408-957-9277 direct this note to Technical Support at VESA

= · Email:     support@vesa.org<= o:p>

= · Mail to:   Technical Support<= /span>

            =       Video Electronics Standards Association

            =       860 Hillview Court, Suite 150

            =       Milpitas, CA 95035<= /span>

Revision History

Version 1.0 -- September 1999

Initial release of the standard

Version 1, Rev. 1 -- March 2000

Document revised throughout, for was condition see previous release.

Version 1, Rev. 2 – December 2002

Revised copyright date, redefined Sync signal testing Section 2.4, replaced Figure = 1 to improve clarity. Revised Table 2, Changed Max Luminance Voltage tolerance to +0.070 / -0.035; to Table 3, added Note 1. ;Revised Acknowledgement List to recognize input from other sources. Added Append= ix B referencing tests from FPDM2.

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= Acknowledgments

;=

The VESA Video Signal Standard is the result of expert input from many sources. VESA acknowledges= and thanks the Display Committee members who contributed to and combined the industry expertise that resulted in this standard. In particular the follow= ing individuals and their companies contributed significant time and effort.

Table of Contents

1.&= nbsp;   Introduction........................................................................= ...........................................................................= .............. 6=

1.1      Compliance with standar= d..........................................= ...........................................................................= ..... 6

1.2      Related VESA documents<= span style=3D'mso-tab-count:1 dotted'>..........................................= ...........................................................................= .......... 6

2.&= nbsp;   VESA Video Signal Definition.................................................................= ............................................................ = 7=

2.1 Synchronization (Hsync and Vsync) Signal Specification..........................................= ............... 7

2.2 Analog Video Outputs.........= ...........................................................................= ........................................................ 8

2.3 Test Circuits..................................................................= ...........................................................................= ..................... 9

2.4 Definition of Terms.................................................................= ...........................................................................= .... 12

2.5 Jitter Measurement Definition..........................................= ...........................................................................= 13

2.6 Glossary of Terms.................................................................= ...........................................................................= ....... 13

2.7 References.....................................................................= ...........................................................................= .................... 14

3.&= nbsp;   Appendix A - Wave Form Diagrams.................................................................= ............................................... 15=

4.&= nbsp;   Appendix B – Suggestions for Tests..........................................= ................................................................. 18=

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List of Figures

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Figure 1-- H V Sync Driver diagram..........= ...........................................................................= .......................................... 10

Figure 2 -- Video terminated measurement fixture= ..........................................= ......................................................... PAGEREF _Toc21424343 \h 11

Figure 3 -- Video Signal Definitions..........................................= ...........................................................................= ........... 12

Figure 4 -- Jitter Measurement Definition= ..........................................= ...........................................................................= 13

Figure 5 -- Pulse Definitions, general..........................................= ...........................................................................= ......... 15

Figure 6 -- Periodic Jitter (positive active pul= se shown)..............................= ........................................................... <= !--[if supportFields]> PAGEREF _Toc21424347 \h 16

Figure 7 -- Voltage Ripple and Noise..........................................= ...........................................................................= ......... 17

1.    Introduction

Display graphics cont= roller technology has leapt forward in the last 10 years at a break-neck pace. Displays have gone from VGA to 1600 x 1200@85Hz and beyond. Graphics controllers have increased performance up to fast 3D imagery with 32-bit pi= xel depth. However, the signal path between the graphics controller and display monitor has remained the same for more than 10 years. With new graphics ASICs running at 2.5 volts, there is no longer any ma= rgin left in the TTL synchronization circuits. With current high bandwidth desig= ns, display signals have little margin left, resulti= ng in monitor jitter and poor front of screen definition. Consequently, there have often been last minute patches by both display vendors and graphics card companies just to get products to work.

This document will gi= ve monitor/graphics vendors a starting point from which to address these issue= s. By using these specifications as a guideline, industry designers will be ab= le to master the art of good signal integrity. This will benefit the industry = as a whole, as well as the end user.

1.1        Compliance with standard

If a supplier does no= t wish to specify compliance with the standard at the minimum pixel clock period, = then the supplier may alternatively specify a longer pixel clock period.

1.2        Related VESA documents<= /span>

VESA Display Specific= ations and Test Procedures (DSTP) Version 1.0 Rev 1.0 - Oct. 3, 1996

VESA Display Data Cha= nnel Standard (DDC) Version 3 - Dec.15, 1997

VESA Enhanced Display= Data Channel Standard (E-DDC) Version 1.0 - Sept. 2, 1999

VESA Flat Panel Display Measurements Standard, Version 2.0 – June 1, 2001 <= /p>