OPTi ChromaCast 82C205 User manual

ChromaCastChromaCast
82C205
LCD Monitor Controller
Preliminary Programmer’s Guide
CONFIDENTIAL
Revision 1.0
915-2000-084
11/22/99
®

Copyright
Copyright © 1999 OPTi Inc. All rights reserved. No part of this publication may be reproduced, transmitted,
transcribed, stored in a retrieval system, or translated into any language or computer language, in any form or by
any means, electronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written permission of
OPTi Inc., 1440 McCarthy Blvd. Milpitas, CA 95035.
Disclaimer
OPTi Inc. makes no representations or warranties with respect to the design and documentation herein described and
especially disclaims any implied warranties of merchantability or fitness for any particular purpose. Further, OPTi Inc.
reserves the right to revise the design and associated documentation and to make changes from time to time in the content
without obligation of OPTi Inc. to notify any person of such revisions or changes.
Trademarks
OPTi and OPTi Inc. are registered trademarks of OPTi Inc. All other trademarks and copyrights are the property
of their respective holders.
OPTi Inc.
1440 McCarthy Blvd.
Milpitas, CA 95035
Tel: [phone]
Fax: [phone]WWW:
http://www.opti.com

Programmer's Guide
ChromaCast 82C205
915-2000-084 Page iii
Revision 1.0
®
Table of Contents
INTRODUCTION........................................................................................................................................................1
NOMENCLATURE.....................................................................................................................................................2
CHOOSING CHROMACAST 82C205 HARDWARE CONFIGURATION .................................................................3
CONFIGURING CHROMACAST 82C205 FOR A SPECIFIC PANEL......................................................................3
DISPLAY CRTC PROGRAMMING..............................................................................................................................4
Pixel Clock Frequency (in MHz):...................................................................................................................4
Horizontal Sync Polarity: ...............................................................................................................................4
Horizontal Sync Width (in units of pixel clock)...............................................................................................5
Horizontal Display Start (in units of pixel clock) ............................................................................................5
Horizontal Display End (in units of pixel clock)..............................................................................................5
Horizontal Total (in units of pixel clock).........................................................................................................6
Vertical Sync Polarity.....................................................................................................................................6
Vertical Sync Width (in units of video lines) ..................................................................................................6
Vertical Display Start (in units of video lines)................................................................................................6
Vertical Display End (in units of video lines) .................................................................................................7
Vertical Total (in units of video lines).............................................................................................................7
Panel Window Default Settings.....................................................................................................................7
DISPLAY TIMING WAVEFORMS.................................................................................................................................8
Vertical Timing for TFT Panel........................................................................................................................8
Horizontal Timing for TFT Panel....................................................................................................................9
Detail of Pixel Clock Timing...........................................................................................................................9
VGA VIDEO INPUT INTERFACE ............................................................................................................................11
CALCULATING THE HORIZONTAL SYNC FREQUENCY (FHSYNC)OF THE INCOMING VGA...............................................11
CALCULATING THE REFRESH RATE OR VERTICAL SYNC FREQUENCY (FVSYNC) OF THE INCOMING VGA.....................11
DETERMINING THE RESOLUTION OF THE INCOMING VGA........................................................................................12
DETERMINING THE FREQUENCY OF THE PIXEL CLOCK USED BY THE VGA ...............................................................12
DETERMINING THE POLARITY OF THE HORIZONTAL AND VERTICAL INCOMING SYNCS..................................................12
CAPTURE CRTC PROGRAMMING ..........................................................................................................................12
HORIZONTAL SYNC WIDTH (IN UNITS OF VCLK1)...................................................................................................13
HORIZONTAL DISPLAY START (IN UNITS OF PIXEL CLOCK)........................................................................................13
HORIZONTAL DISPLAY END (IN UNITS OF PIXEL CLOCK)...........................................................................................13
HORIZONTAL TOTAL (IN UNITS OF PIXEL CLOCK).....................................................................................................13

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page iv
VERTICAL SYNC WIDTH (IN UNITS OF VIDEO LINES).................................................................................................13
VERTICAL DISPLAY START (IN UNITS OF VIDEO LINES).............................................................................................14
VERTICAL DISPLAY END (IN UNITS OF VIDEO LINES)................................................................................................14
VERTICAL TOTAL (IN UNITS OF VIDEO LINES)...........................................................................................................14
PROGRAM THE CAPTURE CRTC TO SYNCHRONIZE TO EXTERNAL SYNCS ...............................................................15
DITHER.....................................................................................................................................................................17
SCALING ..............................................................................................................................................................17
Setting the Input Resolution for the Scaler..................................................................................................17
Setting the Output Resolution......................................................................................................................18
Setting the Scaling Ratios ...........................................................................................................................18
Horizontal Ratio:..........................................................................................................................................19
FINE TUNING THE SCALERS...................................................................................................................................19
USING THE ANTI-ALIAS FILTER..............................................................................................................................20
“CENTERING”.........................................................................................................................................................21
HOW THE DISPLAY WINDOW AFFECTS THE SCALER ...............................................................................................21
SETTING THE PANEL WINDOW REGISTER WITHOUT “CENTERING”...........................................................................21
CONTRAST AND BRIGHTNESS ADJUSTMENT ..................................................................................................23
DIGITAL CONTRAST ..............................................................................................................................................23
DIGITAL BRIGHTNESS............................................................................................................................................23
THE ON SCREEN DISPLAY....................................................................................................................................25
DETERMINING OSD SIZE......................................................................................................................................25
DETERMINING OSD LOCATION ON SCREEN ...........................................................................................................25
SELECTING OSD ATTRIBUTES ..............................................................................................................................25
ALPHA BLEND OPERATION....................................................................................................................................26
CONTENTS OF THE REGISTER COLOR LOOK-UP TABLE ..........................................................................................26
TRANSFERRING BITMAP FROM CPU ROM TO DISPLAY ..........................................................................................26
MEMORY CONFIGURATION AND ALLOCATION.................................................................................................27
BYPASSING THE MEMORY SUBSYSTEM..................................................................................................................27
CONFIGURING THE DRAM INTERFACE...................................................................................................................27
Selecting DRAM speed................................................................................................................................27
Programming the refresh rate......................................................................................................................28
Specifying the burst length and type, and CAS Latency.............................................................................28
Additional memory configuration settings....................................................................................................28
DRAM BUFFER ALLOCATION................................................................................................................................29

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page v
Allocating the DRAM space to each buffer..................................................................................................29
VGA Frame Buffer.......................................................................................................................................30
TV Frame Buffers ........................................................................................................................................30
OSD Buffer ..................................................................................................................................................31
Display Read Out from Frame Buffers ........................................................................................................31
CPU Scratch RAM.......................................................................................................................................32
TESTING AND DEBUGGING..................................................................................................................................33
INTERNAL TEST PATTERNS ...................................................................................................................................33
SOFTWARE RESETS AND DISABLES.......................................................................................................................33
REVISION NUMBER...............................................................................................................................................34
FIFO STATUS ......................................................................................................................................................34
SIGNATURE ANALYZERS .......................................................................................................................................34
CPU MEMORY READ BUFFER...............................................................................................................................34
MEMORY SUBSYSTEM STATUS..............................................................................................................................35
MISCELLANEOUS..................................................................................................................................................35
TV MODE SETUP ....................................................................................................................................................37
SELECTING BETWEEN 8-BIT AND 16-BIT TV DECODER INTERFACE ...........................................................................37
DETERMINING IF TV PHASE IS CORRECT ...............................................................................................................37
REQUIRED SYNCHRONIZATION SIGNALS FROM THE TV DECODER............................................................................37
ENABLING TV MODE.............................................................................................................................................37
PROGRAMMING THE CRTC FOR TV MODE............................................................................................................38
PROGRAMMING THE SCALERS FOR TV MODE ........................................................................................................38
IP CONVERSION...................................................................................................................................................38
Bob Mode ....................................................................................................................................................38
CPU INTERFACE.....................................................................................................................................................41
CPU ACCESS TO THE REGISTERS.........................................................................................................................41
CPU ACCESS TO THE DRAM BUFFER ..................................................................................................................41
INTERRUPTS.........................................................................................................................................................42
Enabling an event to generate an interrupt.................................................................................................42
The interrupt/event status register...............................................................................................................42
Clearing an interrupt/event..........................................................................................................................43
POWER MANAGEMENT FOR CHROMACAST 82C205 .......................................................................................45
TIMER..................................................................................................................................................................45
Setting the timer interval..............................................................................................................................45

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page vi
Timer Operation Procedure.........................................................................................................................45
POWER SEQUENCING ...........................................................................................................................................45
DPMS POWER MANAGEMENT ..............................................................................................................................46
Notifying the CPU of the DPMS state..........................................................................................................46
Monitor is disconnected from the VGA controller........................................................................................46
ChromaCast 82C205 Power Conservation Techniques..............................................................................46
Example of Power Conservation Policy for DPMS......................................................................................47
APPENDIX A: EXAMPLE REGISTER INITIALIZATION VALUES.........................................................................49
APPENDIX B: COMMON VGA TIMING VALUES...................................................................................................51
APPENDIX C: VCLK2 PLL M & N VALUES...........................................................................................................53
APPENDIX D: CHROMACAST OSD (ON-SCREEN DISPLAY) USER'S GUIDE..................................................57
ENABLING OSD....................................................................................................................................................57
SUPPORTED FUNCTIONS.......................................................................................................................................57
Front Panel input buttons description..........................................................................................................57
RESET .................................................................................................................................................................57
SELECT................................................................................................................................................................57
ADJUST................................................................................................................................................................57
MODE ..................................................................................................................................................................57
RESET BUTTON.....................................................................................................................................................57
MODE BUTTON .....................................................................................................................................................57
DESCRIPTION OF SUPPORTED ICONS.....................................................................................................................58
Contrast Icon: ..............................................................................................................................................58
Brightness Icon:...........................................................................................................................................58
Horizontal position Icon: ..............................................................................................................................58
Horizontal Screen size Icon:........................................................................................................................58
Vertical Position Icon:..................................................................................................................................58
Vertical Screen Size Icon:............................................................................................................................58
Focus Icon:..................................................................................................................................................58
OPTi Icon:....................................................................................................................................................58
Recall Icon:..................................................................................................................................................59
USER Recall mode......................................................................................................................................59
Factory Recall mode....................................................................................................................................59
VGA or TV input Select mode Icon..............................................................................................................59
Exit menu.....................................................................................................................................................59

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page vii
OSD Description Language Select..............................................................................................................59
MANUFACTURE DEBUGGING MODE.........................................................................................................................60

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page viii

Programmer's Guide
ChromaCast 82C205
915-2000-084 Page 1
Revision 1.0
®
Introduction
This is the programmer’s guide for the ChromaCast 82C205 LCD Monitor Controller. It is an application note for
the ChromaCast 82C205 Databook that contains detailed register descriptions. This guide will walk the
programmer through the various programming sequences necessary in order to build a customized LCD monitor
control application.
The ChromaCast 82C205 Monitor Controller is a controller for LCD Flat Panel Monitors. The 82C205 performs
several functions including:
•clock generation for the display, and memory,
•scaling,
•frame rate conversion,
•television mode support,
•on screen display menu overlay,
•dithering,
•power management.
The 8051 compatible micro-controller interfaces to the ChromaCast 82C205 LCD Monitor Controller and assists
in the configuration process so the 82C205 can be enabled to perform the above functions. The 8051 will be
referred to hereafter as the CPU or micro-controller.
The CPU initializes the registers of the 82C205, enabling the 82C205 to accept different incoming resolutions and
refresh rates, and allows the 82C205 to interface with many different types of flat panels. In addition, the CPU
provides the on-screen display (OSD) bitmap data to the 82C205, as well as the EDID data used in the Display
Data Channel (DDC). The objective of this programmer’s guide is to present a logical description of each major
function of ChromaCast 82C205 and a methodology for programming these functions. Suggested programming
procedures and values will be included.
This guide is divided into the following sections:
qConfiguring ChromaCast 82C205 for a Specific Panel
This section details how to configure ChromaCast 82C205 for a particular panel. Issues such as the
number of bits per pixel that the panel supports, number of pixels per clock, panel resolution, and the
timing of the panel synchronization signals are discussed. In order to configure the ChromaCast 82C205
properly, the programmer must have a copy of the panel timing specification.
qVGA Video Input Interface
This section details how to detect the incoming resolution and synchronization timing from the VGA, as
well as how to program the ChromaCast 82C205 to accept the incoming VGA signal.
qScaling
This section details how to program the ChromaCast 82C205 Scaler. The 82C205 can display the
incoming video at its original resolution, or it can scale the video up or down to match the panel size. The
video can be displayed full scale on the panel, or in a “centered” mode at its original resolution
surrounded by a black border.
qOn Screen Display
This section details how to overlay an on screen display on top of the video path. Issues such as size and
location of the OSD, color depth, attributes, and other tradeoffs are discussed.
qMemory Configuration and Allocation

Programmer's Guide
ChromaCast 82C205
®
915-2000-084
Revision 1.0 Page 2
This section details how to program the 82C205 so it can interface with the DRAM. This section also
allocates the DRAM to buffers for use by the ChromaCast 82C205.
qTesting
This section indicates what sort of testing and debug options are available on the ChromaCast 82C205.
qTV Mode
This section details how to operate the TV mode on the 82C205. The ChromaCast 82C205 interfaces
with an NTSC/PAL decoder and accepts YUV 4:2:2 format. ChromaCast 82C205 performs a YUV to RGB
color space transform and then performs interlace-to-progressive (IP) scan conversion. Discussions of
different interlace-to-progressive conversion options are included.
qCPU Interface
This section explains the CPU interface to the ChromaCast 82C205, including addressing for the
registers, and the DRAM buffer. The interrupt sources are also explained.
qPower Management
This section explains how to operate the general purpose timer on the 82C205, as it is an integral part of
the power management system. Power sequencing for power-up and power-down on the panels is
explained, as well as policies for DPMS power management.
qExample Register Values for ChromaCast 82C205
Appendix A offers an snapshot of the register values during operation of the 82C205. The setup is for a
1024x768, 60 Hz panel accepting a 1024x768, 70 Hz VGA input.
qCommon VGA Timing Values
Appendix B includes some common VGA Timing values that describe the incoming VGA signal.
qMemory and Display Clock Programming Table
Appendix C includes the programming settings for the internal PLLs for memory clock and display clock
frequencies.
qOn-Screen Display (OSD) User's Guide
Appendix D provides a preliminary user's guide for the use of the On-Screen (0SD) to configure
ChromaCast to provide the most satisfactory image.
Nomenclature
Numbers representing different bases will be denoted as follows: A hexadecimal number will be followed by a
lower case “h”, as in A5h. A number without an “h” appended to it will be assumed to be a decimal value.