VDP1 User`s Manual Supplement
Contents
1. y hapter5 Tables Figure Command table 5 5 sd Chapter 6 Command Tables 79 Figure CMDPMOD 7 10 High speed shrink Pre clipping disable Top End code disable table Delete HSS high speed shrink from bit 12 and Pclp pre clipping from bit 11 of the draw paint mode word CMDPMOD 04H Set both bits 11 and 12 to 0 These bits are not defined in VO Delete HSS high speed shrink from bit 12 and Pclp pre clipping disable from bit 11 Set both bits 12 and 11 to 0 These bits are not defined in VO Delete the explanation of the function of high speed shrink HSS Set bit 12 to 0 This bit is not defined in VO Delete the explanation of the function of pre clipping Pclp Set bit 11 to 0 This bit is not defined in VO Delete end code processing when HSS is 1 HSS is not defined in VO Set HSS to 0 Continued on next page Table 3 1 Changes and Their Descriptions continued Chapter 7 Commands rr Figure Normal sprite draw paint command ES Scaled sprite draw paint command Specification of two coordinate oints Scaled sprite draw paint command Specification of zoom point Distorted sprite draw paint command Polygon draw paint command Figure 16 Figure 19 Figure 13 Figure 13 Figure Polyline draw paint command Line draw paint command Chapter 8 Quick Reference register table Even odd coordinate se2. 4 3 0 Manual Changes ss ns ne Rae 5 3 1 Description of Changes PR 9 5 Version Number VER gM bis 5 Even Odd Coordinate Selection Bit EOS rrrrrrnrrrrrrrnnnnrnvrrnnnnnnvnnnnnr 5 High Speed Shrink HSS mn 5 Pre Clipping Disable Pclp 4 5 3 2 Detailed Descriptions M T snr 6 Introduction This manual contains additional explanations of version 0 of the VDP1 device It explains the functions of version 0 while noting the differences between the func tions of version 1 and the functions of version 0 of the VDP1 device Refer to VDP1 User s Manual 1st edition regarding version 1 This supplement is valid only for version 0 of the VDP1 device Refer to the appro priate manual regarding VDP1 devices other than version 0 Confirmation of Version Number First confirm the version number Use the method described below to confirm the version number Version Number The version number VER version number is handled by bits 15 to 12 of the mode register MODR 100016H thus the version number of the VDP1 device is indicated by four bits Bits 15 to 12 indicate the version number when the mode register is read out When the value is 0 0000B the version number of the VDP1 device is 0 1 0 Differences in Functions 1 1 Functions of Version 0 The differences in the functions of version 0 from the functions of version 1 are ex plained below These functions are not included in the version
3. 0 VDP1 device Refer to the VDP1 User s Manual 1st edition version 1 Even Odd Coordinate Select Bit EOS bit 4 In version 1 an even odd coordinate selection bit EOS was added at bit 4 of the frame buffer change mode register FBCR 100002H However in version 0 this bit does not have that function When writing a value to the frame buffer change mode register FBCR in version 0 set bit 4 to 0 Version 0 does not have the bit for high speed shrink HSS in the draw paint mode word CMDPMOD or that function High Speed Shrink HSS In version 1 high speed shrink HSS is added at bit 12 of the draw paint mode word CMDPMOD 04H However version 0 does not have this function at this bit When drawing painting a scaled sprite or distorted sprite in version 0 set bit 12 of the draw paint mode word CMDPMOD in the command table to 0 Pre Clipping Disable Pcip In version 1 pre clipping disable Pclp was added at bit 11 of the draw paint mode word CMDPMOD 04H However version 0 does not have this function at this bit When a draw paint command is used in version 0 set bit 11 of the draw paint mode word CMDPMOD in the command table to 0 VDP 1 User s Manual Supplement 1 1 2 Functions Added to Version 1 For reference the functions of version 1 which were added after version 0 are ex plained below These functions are not included in version 0 VDP1 devices The newly added f
4. 04 is deleted Bit 12 of CMDPMOD is set to 0 for scaled sprites and distorted sprites Information regarding HSS 1 in the explanation of end code disable is deleted The information regarding HSS 0 remains valid Pre Clipping Disable Pclp Information regarding pre clipping disable Pclp bit 11 of the draw paint mode word CMDPMOD 04 is deleted Bit 11 of FBCR is set to 0 in the draw paint command table VDP 1 User s Manual Supplement 5 3 2 Detailed Descriptions The items changed for version 0 and their descriptions are given in the table below VO in the table refers to version 0 of the VDP1 device Table 3 1 Changes and Their Descriptions Page Line lem Description 9 Chapter4 System Registers o System Registers 38 Top Frame buffer change mode figure register wi Even odd coordinate selection bit Delete change timing of even odd coordinate selection bit EOS This bit is not defined in version 0 Delete even odd coordinate selection bit EOS Set bit 4 to 0 This bit is not defined in VO Delete explanation of function of even odd coordinate selection bit EOS Set bit to 0 This bit is not defined in VO Delete even odd coordinate selection bit EOS Bit 7 is undefined This bit is not defined in VO The value of bits 15 12 is 0 00008 Even odd coordinate selection bit Delete even odd coordinate selection bit EOS HE VS Ge Mode register
5. CMDPMOD Set bit 11 of CMDPMOD to 0 Delete HSS and Pclp from CMDPMOD Set bits 12 and 11 of CMDPMOD to 0 Delete Pclp from CMDPMOD Set bit 11 of CMDPMOD to 0 Delete even odd coordinate selection Delete high speed shrink Delete pre clipping
6. EOS of the frame buffer change mode register FBCR When 0 is specified the original picture data are sampled irrespective of even or odd coordinates at any magnification ratio Use 0 to give precedence to accuracy over speed and use 1 to give precedence to speed Pre Clipping Disable Pclp Pre clipping disable Pclp has been added at bit 11 of the draw paint mode word CMDPMOD 04H This bit specifies whether pre clipping is performed or dis abled When 0 is specified pre clipping is performed When 1 is specified pre clipping is not performed One drawing painting command comprises a group of several lines and the re spective lines comprise a number of dots Each dot is drawn painted based on clipping area drawing painting area information specified by the CPU A line that is completely removed from the drawing painting area and an entire 1 line drawing painting is not required can be detected in advance and drawing painting efficiency can be increased by not allowing the drawing painting to be started Also when one end of 1 line is outside the drawing painting area effi ciency can be improved by starting drawing painting from inside the drawing painting area that line is limited to vertical and horizontal directions The VDP1 normally performs this detection but in the case of small elements whose points are in the A B or D C direction the overhead r
7. General Notice When using this document keep the following in mind 1 This document is confidential By accepting this document you acknowledge that you are bound by the terms set forth in the non disclosure and confidentiality agreement signed separately and in the possession of SEGA If you have not signed such a non disclosure agreement please contact SEGA immediately and return this document to SEGA This document may include technical inaccuracies or typographicalerrors Changes are periodi cally made to the information herein these changes will be incorporated in new versions of the document SEGA may make improvements and or changes in the product s and or the program s described in this document at any time No one is permitted to reproduce or duplicate in any form the whole or part of this document without SEGA S written permission Request for copies of this document and for technical information about SEGA products must be made to your authorized SEGA Technical Services representative No license is granted by implication or otherwise under any patents copyrights trademarks or other intellectual property rights of SEGA Enterprises Ltd SEGA of America Inc or any third party Software circuitry and other examples described herein are meant merely to indicate the character istics and performance of SEGA s products SEGA assumes no responsibility for any intellectual property claims or other problems that m
8. ay result from applications based on the examples describe herein It is possible that this document may contain reference to or information about SEGA products development hardware software or services that are not provided in countries other than Japan Such references information must not be construed to mean that SEGA intends to provide such SEGA products or services in countries other than Japan Any reference of a SEGA licensed prod uct program in this document is not intended to state or simply that you can use only SEGA s licensed products programs Any functionally equivalent hardware software can be used instead SEGA will not be held responsible for any damage to the user that may result from accidents or any other reasons during operation of the user s equipment or programs according to this document NOTE A reader s comment correction form is provided with this document Please address comments to SEGA of America Inc Developer Technical Support att Evelyn Merritt 150 Shoreline Drive Redwood City CA 94065 SEGA may use or distribute whatever information you supply in any way it believes appropriate without incurring any obligation to you 6 27 95 002 SEGA SEGA OF AMERICA INC Consumer Products Division VDP User s Manual Supplement Doc ST 13 SP1 052794 1994 SEGA All Rights Reserved READER CORRECTION COMMENT SHEET Keep us updated If you should come across any inc
9. equired for that detec tion up to five CPU clock cycles for one line becomes conspicuous and can lower the drawing painting efficiency In the case of large elements that extend greatly out of the drawing painting area it is more efficient to perform pre clipping This bit is only valid for drawing paint ing commands Fix it to 0 for other commands VDP 1 User s Manual Supplement 3 2 0 Using Version 0 Use version 0 as described below 2 1 High Speed Shrink HSS When drawing painting scaled sprites and distorted sprites reduced in version 1 it is possible to specify high speed shrink in order to give precedence to speed Version 0 does not have this function In order to give precedence to speed when scaled sprites and distorted sprites are scaled down and drawn painted a method other than one that scales down and draws paints scaled sprites and distorted sprites is required For example a method that draws paints using scaled sprites or that registers reduced scaled sprites or distorted sprites and draws paints them without reduc tion must be used If the drawing painting speed is slow in version 0 confirm whether or not a scaled sprite or distorted sprite is being scaled down and drawn 2 2 Pre Clipping Disable Pclp When pre clipping is not required in version 1 drawing painting speed can be raised by specifying pre clipping disable Version 0 does not have this function When drawing paint
10. ing small horizontal or vertical lines it is necessary to employ a method that reduces the overhead required to detect whether drawing painting with pre clipping is necessary For example measures must be taken by making several small elements large when drawing painting them or exchanging left and right for up and down and increas ing the size when drawing painting them If the drawing painting speed is slow in version 0 confirm whether or not many small elements are being drawn painted 3 0 Manual Changes The manual for version 1 can be changed into the manual for version 0 by making the following changes 3 1 Description of Changes The items changed include explanations of the three bits added and their functions The manual can be used for version 0 by deleting the explanations of these func tions Version Number VER The value of the version number VER bits 15 12 of the mode register MODR 100016H is 0 0000B Even Odd Coordinate Selection Bit EOS Information regarding the even odd coordinate selection bit EOS bit 4 of the frame buffer change mode register FBCR 100002H is deleted Bit 4 of FBCR is set to 0 Information regarding the even odd coordinate selection bit EOS bit 7 of the mode register MODR 100016H is also deleted Bit 7 of MODR becomes unde fined High Speed Shrink HSS Information regarding high speed shrink HSS bit 12 of the draw paint mode word CMDPMOD
11. ink HSS and pre clipping disable Pclp to draw paint mode word 04H in the command table e Total 163 pages March 31 1994 e Explained functions for version 0 of the VDP1 device The following functions added to version 1 are not included in version 0 gt The frame buffer change mode register FBCR does not have an even odd coordinate selection bit EOS function gt The draw paint mode word 04H in the command table does not high speed shrink HSS and pre clip ping disable Pclp functions e Total 7 pages Table of Contents mMOde TION Aer i Confirmation of Version Number rrrrnnnnnnnvnnnrnnnrrnnnnnnrvrrnnnnnnnnnnernnnrenersnsrrnessrnnknne i 1 0 Differences in Functions sissies svete ioe diemi il eaten RSC Mal e ie 1 1 Functions of Version O0 2 N 1 Even Odd Coordinate Selection Bit EOS rrrrrrnrrrrrrrnnnnnvvvnennnnnrvnnenr 1 High Speed Shrink HSS AR ONS nnn 1 Pre Clipping Disable Pclp ON 1 1 2 Functions Added to Version 1 eeeeeeee 2 Even Odd Coordinate Selection Bit EOS rrrrrndrrrrrrnnrennvrrnnrnnnvnnennr 2 High Speed Shrink HSS M Bree reece 2 Pre Clipping Disable Pclp Ne 7 3 2 0 Using Version Dua Vee cated Masner roret MAP Tec ae ed ts eee 4 2 1 High Speed Shrink HSS cece cee Ne MMe cence ceeee renee 4 2 2 Pre Clipping Disable Pclp 8 3 7
12. lection bit Delete Pclp from CMDPMOD Delete Pclp definition Set bit 11 of CMDPMOD to 0 Delete HSS and Pclp from CMDPMOD Delete definition of HSS and Pclp Set bits 12 and 11 of CMDPMOD to 0 Delete Pclp from CMDPMOD Delete definition of Pclp Set bit 11 of CMDPMOD to 0 Delete even odd coordinate selection bit EOS Set bit 4 of MODR to 0 Delete even odd coordinate selection bit EOS Set bit 4 of MODR to 0 Delete even odd coordinate selection bit EOS Bit 7 of MODR is undefined Delete even odd coordinate selection bit EOS Figure Command table Delete HSS and Pclp from CMDPMOD Set both bits 11 and 12 of CMDPMOD to 0 Draw paint mode word Bag speed shrink Pre clipping disable Mis ES table ead eae Normal sprite draw paint table Scaled sprite draw paint command figure command Polygon draw paint command figure NU 1 Line draw paint command figure TN nde S right 33 162 right 42 command Beal el 154 Distorted sprite draw paint 155 Top Polyline draw paint command figure rn VDP 1 User s Manual Supplement Delete HSS high speed shrink from bit 12 and Pclp pre clipping disable from bit 11 Set both bits 12 and 11 to 0 Delete high speed shrink HSS Set bit 12 of CMDPMOD to 0 Delete pre clipping Pclp Set bit 11 of CMDPMOD to 0 Delete end code processing when HSS is 1 HSS is not defined in VO Set HSS to 0 Delete Pclp from
13. orrect or outdated information while reading through the attached document or come up with any questions or comments please let us know so that we can make the required changes in subsequent revisions Simply fill out all information below and return this form to the Developer Technical Support Manager at the address below Please make more copies of this form if more space is needed Thank you General Information Your Name Phone Document number ST 13 SP1 052794 Date Document name VDP1 User s Manual Supplement Corrections Questions comments Where to send your corrections 415 802 3963 Mail SEGA OF AMERICA Attn Manager Attn Manager Developer Technical Support Developer Technical Support 275 Shoreline Dr Ste 500 Redwood City CA 94065 REFERENCES In translating creating this document certain technical words and or phrases were interpreted with the assistance of the technical literature listed below 1 Dictionary of Science and Engineering 350 000 words 3rd Edition Inter Press Tokyo Japan 1990 2 Computer Dictionary Kyoritsu Publishing Co LTD Tokyo Japan 1978 3 IBM Dictionary of Computing McGraw Hill Inc New York New York 1994 Revision History Revision 7 1 First Edition Supplement December 6 1993 e Minor corrections e Total 155 pages March 20 1994 e Added even odd coordinate selection bit EOS to frame buffer change mode register FBCR e Added high speed shr
14. unctions are as follows For more information refer to each item Even Odd Coordinate Select Bit EOS bit 4 An even odd coordinate selection bit EOS was added at bit 4 of the frame buffer change mode register FBCR 100002H This bit becomes valid when 1 is specified for high speed shrink in drawing painting a scaled sprite or a distorted sprite When HSS 1 is specified lines with respect to which the drawing is scaled down are drawn by sampling only pixels at even or odd coordinates in the original picture data The sampling of pixels at even or odd coordinates is specified by this bit If EOS 0 then pixels at even coordinates are sampled and if EOS 1 then pixels at odd coordinates are sampled When HSS 0 this bit is not referenced High Speed Shrink HSS High speed shrink was added at bit 12 of the draw paint mode word CMDPMOD 04H When scaling down and drawing a scaled sprite or a distorted sprite this bit is used to select whether precedence is given to speed or to accuracy This is valid only for the drawing painting commands of scaled sprites and distorted sprites Leave it fixed at 0 for all other drawing commands When 1 is specified for this bit lines with respect to which the drawing is scaled down are drawn by sampling only the even or odd pixels of the original picture data The selection of even coordinates or odd coordinates is done with the even odd coordinate selection bit
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