ST-103-R1-040194.pdf

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SEGA Confidential

Saturn Overview

Manual

(temporary version 1)

June 6, 1994

Doc. #ST-103-R1-040194

CONTENTS

Introduction

(i)

Manual Layout

(i)

Related Manuals

(ii)

Definitions

(iii)

List of Figures

(vi)

List of Tables

(vii)

Chapter 1 Introduction to Saturn

1.1 Highlights

Chapter 2 Structure

2.1 Hardware Specifications

2.2 System Configuration

2.3 Description of Each Part

Chapter 3 Functions

3.1 CPU

3.2 SCU

3.3 VDP1

3.4 VDP2

3.5 SCSP

3.6 CD-ROM

3.7 Other Items

Index

SEGA Confidential

READER CORRECTION/COMMENT SHEET

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pg. #

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ST-103-R1-040194

Saturn Overview Manual

SEGA Confidential

REFERENCES

In translating/creating this document, certain technical words and/or phrases were interpreted with the
assistance of the technical literature listed below.

KenKyusha New Japanese-English Dictionary
1974 Edition

Nelson's Japanese-English Character Dictionary
2nd revised version

Microsoft Computer Dictionary

Japanese-English Computer Terms Dictionary
Nichigai Associates

4th version

SEGA Confidential

Introduction

This manual gives an overview of the hardware for Saturn, Sega's Multimedia
Home Entertainment Device, which contains a 32-bit RISC (Reduced Instruction Set
Computer) processor. This manual explains the features and functions of Saturn to
those who develop game software.

Manual Layout

This manual consists of the following chapters, supplements, and index.

Chapter 1

Introduction to Saturn
The features of Saturn are explained.

Chapter 2

Structure
The internal structure of Saturn plus hardware specifications
are explained.

Chapter 3

Functions
The main functions of Saturn are explained.

· CPU

The main CPU, sound CPU, I/O controller.

· SCU

Control of each bus (A-bus, B-bus, CPU-bus),
DMA transfer, and matrix calculation (DSP).

· VDP1

Control of drawing and defines draw control.

· VDP2

Control of the scroll screen and display.

· SCSP

Sound control of the PCM/FM sound source.

· CD-ROM

An overview of the CD-ROM and MPEG.

· Miscellaneous

Explains the SMPC.

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VDP1

User's

Manual

VDP2

User's

Manual

SCU

User's

Manual

SCSP
User's

Manual

SATURN

OVERVIEW

SMPC

User's

Manual

Related Manuals

SEGA Confidential

Definitions

DSP (Digital Signal Processor)

This high-speed digital processor mainly performs rapid addition and subtraction.

Gouraud Shading

Gouraud is one type of computer algorithm.
This process computes the color of each position (dot, pixel) of each object being
displayed. Places hit by light are bright, and places shadowed are dark.

An error process that corrects errors when data is read from a CD.

Frame Buffer

Frame buffer is RAM that stores pictures to be displayed. The line buffer was lim-
ited to pictures arranged in a horizontal direction, but with the RAM of the TV
screen size, there you are no longer limits in the horizontal direction.

Pixel

A unit that represents a picture element in a drawing.

PCM Sound Generator (Pulse Code Modulation Sound Generator)

A method of storing in memory PCM data created from sound, reading the sound
from memory at the time that the sound is to be played, and outputting the sound.

Interlace

An image output scan system that obtains the screen image of a single frame by
scanning it twice.

iii

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MPEG (Motion Picture (image coding) Expert Group)

An international standard of compression for color motion images (including voice)
of television and video. This standard allows the playing of Full Screen, Full Color,
Full Motion, and CD Quality Audio. Besides conforming to the international stan-
dard, it also has original special functions.

Parts

Divides textured and non-textured parts in a drawing done by the draw command.

Perspective

A technique for creating the impression of distance in computer graphics by show-
ing distance objects as small and nearby objects as large.

Sprite

Image patterns that can be rapidly moved and re-drawn. By preparing a number of
sprite patterns and re-drawing them while moving designated coordinates, an
animation effect can be produced in which the game character appears to be mov-
ing.

High Resolution

Both the normal TV and special monitor are able to display at a high resolution, but
the special monitor has a higher resolution.

Texture Mapping

A computer graphics technique that allows a pattern to be placed on an object.

PCM (Pulse Code Modulation)

A method of dividing sound (wave forms) according to a time axis, and converting
the peak values into digital data. Data found by this method is called PCM data.

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Effect Data

Expresses the resulting sound obtained when a sound created by the sound genera-
tor is affected by passing through the DSP.

Reverb

As one type of sound field effect, one can produce the atmosphere of a hall, stage
room, steel plate, etc.

PLL (Phase Locked Loop)

Refers to the phase-locked circuit (IC) that follows to the input signal.

IPL (Initial Program Loading)

A list process language. It outputs the designation that loads programs from the
designated I/O device to the processing device.

Clipping

Clipping removes all image data located outside of the designated draw access area.

PAL System (Phase Alternation by Line system)

Developed in West Germany, this is a color television broadcasting standard of 625
scan lines and 25 images per second.

NTSC System (National Television System Committee system)

Recognized by the FCC (Federal Communication Commission) and applied by
Japan, the United States, South Korea,among others; this standard of color television
broadcasting has 525 scan lines and 30 images per second.

SEGA Confidential

List of Figures

Chapter 2 Structure

Figure 2.1 System Block Diagram

Chapter 3 Functions

Figure 3.1 SCU System Configuration

Figure 3.2 VDP1 System Configuration

Figure 3.3 Regular Sprites

Figure 3.4 Scaled Sprites

Figure 3.5 Distorted Sprites

Figure 3.6 Polygon, Polyline, Line

Figure 3.7 Configuration of the Color Bank Method

Figure 3.8 Gouraud Shading

Figure 3.9 Mesh Process

Figure 3.10 System Clipping

Figure 3.11 User Clipping

Figure 3.12 VDP2 System Configuration

Figure 3.13 Scroll, Priority Functions

Figure 3.14 Mosaic Pattern

Figure 3.15 Image Modification by Axis Rotation

Figure 3.16 Image Modification by Screen Axis

Figure 3.17 Cell Format Scroll Screen

Figure 3.18 Bit Map Scroll Screen and Data Setting Relationship

Figure 3.19 Windows

Figure 3.20 Priority Function

Figure 3.21 Color Calculation Function

Figure 3.22 Insertion of the Line Color Screen

Figure 3.23 Shadow Function

Figure 3.24 Blur Calculation Function

Figure 3.25 SCSP System Configuration

Figure 3.26 Tunnel and BGM Reverb

Figure 3.27 Tennis Game Example

Figure 3.28 CD-ROM System Configuration

Figure 3.29 CD-ROM System Data Flow

Figure 3.30 Stream Select Function

Figure 3.31 Window Function

Figure 3.32 Interpolation, Shading, Mosaic Functions

Figure 3.33 Chroma Key Function

Figure 3.34 SMPC System Configuration

SEGA Confidential

List of Tables

Chapter 2 Structure

Table 2.1 Hardware Specifications <Main System>

Table 2.2 Hardware Specifications <Subsystem>

Chapter 3 Functions

Table 3.1 CPU Specifications

Table 3.2 SCU System Specifications

Table 3.3 VDP1 System Specifications

Table 3.4 Parts Classification

Table 3.5 Interlace

Table 3.6 Types of Color Operations

Table 3.7 VDP2 System Specifications

Table 3.8 Scroll Screen Functions

Table 3.9 SCSP System Specifications

Table 3.10 CD-ROM System Specifications

Table 3.11 CD Drive Specifications

Table 3.12 Corresponding Standards

Table 3.13 SMPC Functions

Table 3.14 Saturn Digital PAD Specifications

vii

SEGA Confidential

Chapter 1 Introduction to Saturn

Contents

Highlights

Saturn Overview Manual

SEGA Confidential

1.1

Highlights

· Leading Edge CD-ROM Drive

· High-Speed Micro-Processor

· Large-Capacity Memory

· The main CPU is a 32-bit RISC chip

- SH-2 loader that supports a DSP-type computer.

· Memory

- 32 Mbits (4 Mbytes)
- 4 Mbit (512 Kbyte) CD-ROM

· Powerful Graphics Functions

- Up to 16,777,216 colors
- 24 million pixels/Sec (VDP1)
- Sprite processor that can display polygons
- High performance background processor

SEGA Confidential

SATURN

SEGA

DUAL CPU MULTI AMUSEMENT PLAYER

SEGA CD ROM / CARTRIDGE

· Improved Sound Functions

- 32 Channel PCM sound generator
- FM sound generator
- Audio-only effect DSP loader

· Leading Edge CD-ROM Drive

- 32-bit RISC chip SH-1 loader
- MPEG (optional)

· Development Language

- C language, Assembly language

Saturn Overview Manual

SEGA Confidential

Chapter 2 Structure

Contents

2.1 Hardware Specifications

2.2 System Configuration

2.3 Description of each Part

Saturn Overview Manual

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2.1

Hardware Specifications

Saturn hardware specifications are shown below.

Table 2.1 Hardware Specifications <Main System>

Table 2.2 Hardware Specifications <Subsystem>

SH-2 X 2

CPU

32-bit RISC Chip 28.6MHz / 26.8

Internal Math Processor

RAM

2MB

CPU BLOCK

ROM

512KB

SCU

DMA 2 ch

DSP 14.3 MHz

SMPC

RTC 1 MHz (accuracy)

Employs Peripheral Interface

VDP1

Max. 400,000 pixels, 1/60 sec. transfer

VIDEO BLOCK

VDP2

Screen Resolution 320 dot (H) X 224 dot (V)

up to 5 background screens

RAM

VDP1: 1 MB

VDP2: 512 KB

SCSP

PCM 32 ch, max. 44.1 KHz

DSP 22.6 MHz Acoustic effects only

SOUND BLOCK

RAM

512KB

CPU

MC68EC000

16-bit CISC 11.3 MHz

CPU

SH-1

32-bit RISC Chip 20.0 MHz

RAM

512 KB

MPEG AUDIO / VIDEO

(optional)

RAM 512KB

Screen Resolution 704 dot (H) X 480 dot (V)

30 frame/sec animation, 44.1 KHz 16-bit audio

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2.2

System Configuration

With a DSP function built-in to the 32-bit RISC chip (SH-2) that is loaded on to the
main CPU, the system configuration has greatly improved the processing perfor-
mance.

RAM512KB

ROM64KB

MPEG

VIDEO

< SUBSYSTEM >

MPEG

VIDEO

SH-1

CD-ROM

DRIVE

I / F

CARTRIDGE I/F

RAM512KB

RAM1MB

RAM512KB

VDP1

VDP2

ROM512KB

RAM2KB

SOUND BLOCK

SCSP

MC68EC000

VIDEO BLOCK

ENCODER

D/A CONVERTER

(SOUND)

SMPC

AUDIO

OUT

VIDEO

OUT

PAD I/F

< MAIN SYSTEM >

SCU

SH-2 X 2

CPU BLOCK

OPTIONS

RAM2MB

Figure 2.1 Block Diagram

Saturn Overview Manual

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2.3

Description of Each Part

The block diagram in Figure 2.1 is explained below.

Main System

SH-2 (X2)

Control of the entire system is done by the main CPU. With a RISC type high-speed
CPU, there is a noticeable difference in processing performance over conventional
systems. Processing power has been dramatically improved due to a processor
inside that has an arithmetic unit similar to that of a DSP.

MC68EC000

The MC68EC000 carries a 16-bit CPU for sound. Processing speed is much faster
than earlier systems.

RAM/ROM

The RAM has a total of 32 Mbits, with 16 Mbits in the main CPU, 4 Mbits in the
sound CPU, and the remaining 12 Mbits allocated to video. ROM contains the initial
hardware program and cartridge as well as the CD IPL program. It also contains a
CD library.

SMPC (System Manager & Peripheral Control)

SMPC controls reset of the entire system and interfaces with peripheral devices such
as a control pad. Also, with an internal RTC (Real Time Clock) you can get the date
and time. When the power is off the RTC function is backed-up by a battery.

SCU (System Control Unit)

The SCU controls all buses (A-bus, B-bus, CPU-bus) and functions as a co-processor
of the main CPU. Because the DMA controller is loaded internally, character data
can be transferred to V-RAM when the main CPU is operating.

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VDP1 (Video Display Processor 1)

VDP1 controls sprites (character). The limitation in the number of horizontal sprites
of previous systems has been eliminated, allowing more sprites (characters) to be
displayed. Polygons can also be displayed.

VDP2 (Video Display Processor 2)

VDP2 controls display of the background screen (scroll screen) as well as the display
priority order. This has expanded the number of scroll screens that can be displayed
at the same time to a maximum of five, and enables the screen to be moved up,
down, right, and left and to be rotated.

SCSP (Saturn Custom Sound Processor)

The SCSP controls the sound of the PCM/FM sound generator. It supports the FM
sound generator of conventional systems and can support PCM sound. Tone quality
has improved to CD-D/A (Compact Disc - Digital / Audio) levels.

Cartridge I/F

This is the connector I/F for the cartridge. A maximum of 57 MB area has been
provided.

PAD I/F

This is a control pad connector I/F. Two are planned to be loaded into the main
system.

D/A Converter, Encoder

This changes the digital signal of sounds to an analog signal (D/A converter). In the
case of color, analog RGB is converted to video signals (encoder).

Saturn Overview Manual

SEGA Confidential

Subsystem

CPU

The CPU manages mechanical control, error correction (C3), and CD file manage-
ment.

RAM/ROM

RAM is used as CD buffer RAM, MPEG work RAM, and in the data cache for CD
error correction. ROM contains programs such as the CPU CD BIOS.

CD-ROM Drive

Saturn employs a X2 speed CD-ROM drive.

MPEG (optional)

This standard allows the playing of Full Screen, Full Color, Full Motion, and CD
Quality Audio. Up to 72 minutes (30 frames per second) of images and sounds can
be recorded on a single CD. In addition, there are various application capabilities
that not only output the stretched images, but capture them within the system and
enable their processing using MPEG technology.

SEGA Confidential

Chapter 3 Functions

Contents

3.1 CPU

3.2 SCU

3.3 VDP1

3.4 VDP2

3.5 SCSP

3.6 CD-ROM

3.7 Other Items

Saturn Overview Manual

SEGA Confidential

3.1

CPU

The main CPU has a 32-bit RISC chip with built-in DSP function. The sound block
has a 16-bit CPU MC68EC000. The subsystem has a SH-1. The specification of each
CPU is shown in Table 3.1.

Table 3.1 CPU Specifications

· SMPC (System Manager) is the processor configuration.

See "3.7 Other Items" for more about functions.

SH-2

· RISC Type Instruction Set

· Internal and External 32-bit buses

· Cache 4 Kbyte

· Clock 28.6 MHz / 26.8

· Internal Math Processor

SH-1

· RISC Type Instruction Set

· Internal A/D Converter

· Internal 32-bit bus and External 16-bit bus

· Clock 20 MHz

· Cache 4 Kbyte

· Internal Math Processor

MC68EC000

· Internal 16-bit bus and External 16-bit bus

· CISC Type Instruction Set

· Clock 11.3 MHz

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3.2

SCU

The SCU smoothly executes the interface of more than one processor connected to
CPU-bus, A-bus, and B-bus. Further, inside is a DMA controller, interrupt controller,
and DSP.

System Configuration

The SPMC is connected to the CPU-bus and controls the system reset signal as well
as the control pad.

The A-bus is connected to a device that provides programs such as cartridges and
CDs.

The SCU interrupt controller controls interrupt from A-bus, B-bus, and the SMPC. It
also supports timer interrupt, can cause the screen display to synchronize and inter-
rupt (INT signal) (Figure 3.1).

CPU

SCU

RAM

ROM

SMPC

A-Bus

B-Bus

INT Signal

CPU-bus

Figure 3.1 SCU System Configuration

Saturn Overview Manual

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System specifications of the SCU are shown in Table 3.2.

Table 3.2 SCU System Specifications

Item

Specification

Remarks

DSP

· 32bit X 32bit

48bit

· 14 MHz

· Program RAM 32bit X 256word

· DATA RAM 32bit X 64word X 4

· DMA command

DMA

· CPU 3 ch, DSP 1 ch

· 3 level, stack 1 set

· Able to start by interrupt

· Indirect mode

Interrupt Control

· Timer (2ch) synchronized with screen

· Interrupt control from external terminal

A-bus Control

· A-bus (external bus) bus sizing

· Wait control

· Burst size setting

· Refresh control

B-bus Control

· B-bus (internal bus) control

· VDP1, VDP2, SCSP only

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Functions

SCU functions are shown below.

· Data transfer within A-bus, B-bus, and CPU-bus
· Matrix calculations by DSP
· SCU internal interrupt control by interrupt controller

· Data transfer within Main CPU, Internal DSP, A-bus, and B-bus

The SCU has a CPU I/F, A-bus I/F, and B-bus I/F and smoothly executes the inter-
face to multiple processors, which are connected through their respective I/F and
buses. This also allows programs in the main CPU to be transferred to the DSP
within the SCU. Also, while data is being transferred between the A-bus and B-bus,
the work area can be accessed using the CPU-bus from the CPU, and process can be
executed using independent buses in parallel.

· Interrupt Control

Interrupt that extends to other processors executes through the SCU. For example,
to display the volume level on screen, a screen display request interrupt from the
SCSP for the SCU occurs. SCU recognizes the interrupt and issues the interrupt
while synchronized with the screen. Interrupt can then be issued with respect to any
point (dot) on the screen.

Internal DSP

SCU has an internal DSP. This has been provided in order to implement processes
difficult to implement when the load to the main CPU has been excessive.

Operating Frequency

The operating frequency of the DSP inside SCU runs at a frequency of 1/2 the main
CPU. See the Main CPU manual concerning the operating frequency of the main
CPU

Saturn Overview Manual

SEGA Confidential

3.3

VDP1

VDP1 controls sprites.
Compared to conventional systems, drawing speed is exceptionally fast, and be-
cause there is no limit in the number of horizontal sprites, more sprites (characters)
can be displayed. Polygons can be displayed as sprite applications.

System Configuration

The VRAM and two frame buffer screens are connected to VDP1 (Figure 3.2). The
VRAM draw command is set through the SCU from the CPU. VDP1 reads draw
commands from the VRAM and writes (draws) draw data to the frame buffer. Infor-
mation controlling draw is set in the system register inside VDP1. Drawn frame
buffer data is displayed in the TV through VDP2 that controls image display.

CPU

SCU

VRAM

Frame Buffer

VDP2

System

VDP1

Figure 3.2 VDP1 System Configuration

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Table 3.3 shows the VDP1 system specifications.

Table 3.3 VDP1 System Specifications

Item

Specification

Remarks

Texture Parts

Display

· Regular Sprites

(normal sprite, horz. 8~504 dot,

vert. 1~255 dot)

· Expand/Contract Sprite

(any size can be designated by vertical
horizontal 1 dot units)

· Distorted Sprite

(can designate any 4 vertices)

Up-down-left-right
reverse by all sprites is
possible

Non-Texture Parts

Display

· Quadrilateral polygon

· Polyline

· Line

You can have a three

sided polygon and
polyline if two adjacent
points have the same
coordinates

Color Calculation

· Semi-transparent associated parts

· Half brightness

· Shadow

· Mesh

· Gouraud Shading

Gouraud shading can be
combined with semi-
transparent or half
brightness

Draw Method

· Double Frame Buffer Method

(Can enlarge, reduce, rotate, and modify
the entire plane of the frame buffer.

Can designate the delete range and
delete data of frame buffer.

Can set write local coordinates.

Can designate clipping of rectangular
area.)

Simultaneous Colors

· 16, 64, 128, 256, 32768 colors

16, 64, 128, 256

for high resolution

Memory Capacity

· VRAM 4 Mbit

(Character Generator, for all types of
tables)

· Frame buffer 2 Mbit X 2 sides

(Both 2 sides can be used as bit map.
One side is displayed.)

Saturn Overview Manual

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Functions

The main functions of the VDP1 are shown below.
· Draws parts (character line)
· Designates color mode
· Color calculation
· Mesh process
· Designates clipping coordinates and relative coordinates
· Display control of frame buffer

Parts, color mode, and coordinates are controlled by the VRAM command table.
Control of the frame buffer display is done by the system register.

Parts

Parts drawn by VDP1 are divided into texture and non-texture parts depending on
whether or not there is an original picture. Table 3.4 shows part classifications.

Table 3.4 Parts Classification

Classification

Parts Name

Function

Defining Method

Texture Parts

Regular sprite

Character, up-down,

left-right reverse

Read direction of 1
vertex

P
A
R
T
S

Rectangular sprite

Character, up-down,
left-right reverse,
enlarge-reduce,
expand-contract are
possible

Read direction of 2
vertices, or read
direction of fixed
points and width

Transformed sprite

Character, up-down,
left-right reverse,
enlarge-reduce,
expand-contract,
rotation, twisting are
possible

Read direction of 4
vertices

Non-Texture Parts

Polygon

Quadrilateral

Inside is painted solid

4 vertices

Polyline

Quadrilateral

4 vertices

Line

Straight Line

Start and End points

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Texture Parts

Sprites draw character patterns. Character patterns define pixel data as character
pattern tables in VRAM.

Regular Sprites

Normal rectangular sprite.
The pattern of the original picture can be inverted up , down, and left and right.
This can be done in any sprite mode (Figure 3.3).

Original

Drawings

Normal

Left-Right

Reverse

Up-down

Reverse

Up-Down

Left-Right Reverse

Figure 3.3 Regular Sprites

Scaled Sprites

For sprites that can be enlarged and reduced, it is only possible to zoom in and out
vertically and horizontally (Figure 3.4).

Expand Horizontally

and Vertically

Expand Vertically

Expand Horizontally

< Original >

Normal

Reduce

Horz.

Reduce Vert

< Drawings >

Figure 3.4 Scaled Sprites

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Distorted Sprites

These are sprites that can be distorted. The original picture can be distorted to any
shape by designating four vertices of the character and enlarging, reducing, rotating,
and reversing the picture in any way. If viewed as a polygon, it would be the same
as a texture-mapped polygon.

ORIGINAL

ROTATE

PUSH AT1 POINT

PULL AT1 POINT

TWIST

SHIFT ALL POINTS

CHANGE SHAPE

PUSH IN TOWARD CENTER

Figure 3.5 Distorted Sprites

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Non-Texture Parts

Polygon

This is a four-vertex polygon. It is different with a sprite in that the flat surface
encompassed by the four points is painted over by one color. Sprites have an origi-
nal picture whereas polygons do not.

Polyline

This is a quadrilateral connected by four lines.

Line

This is a line of one color drawn between two points.

POLYGON

LINE

POLYLINE

Figure 3.6 Polygon, Polyline, Line

Display

A common TV is used as a display apparatus. NTSC format is the TV standard of
both Japan and the U.S. Europe uses the PAL format.

TV display is done by reading data from lead of the frame buffer for each frame (1
frame per 1/60 sec.).

Normally, one frame is equal to one field, but one frame that is interlaced is treated
as two fields, allowing the vertical resolution to be doubled (one frame per 1/30
sec.). There is single and double interlace, as shown in Table 3.5.

Table 3.5 Interlace

Saturn Overview Manual

Double Interlace

Odd numbered line, a different image is shown by even numbered lines

Single Interlace

Odd numbered line, the same image is shown by even numbered lines

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Color Mode Designation

There are three methods of designating color modes for textured parts: the color
bank, RGB code, and color look-up. Non-textured parts have pixel data for color
designation.

Color Bank Method

· Combining color bank with 16, 64, 128, and 256 color palette codes, references

colors stored in the VDP2 color RAM.

· VDP2 color palette is selected by the color bank. Color from the color palette is

selected by the palette code.

· 16, 64, 128, 256 colors can be expressed by 1 character.
· Data written by the color bank method is divided and processed by the VDP2

color operation, priority, color bank, and function bits of the palette code.

Color Bank

Palette Code

MSB

LSB

Color Operation

Priority

Figure 3.7 Configuration of the Color Bank Method

RGB Code Generation

Color is expressed by five bits of respective RGB (red, green, blue) luminance.

Color Look-up Table

Colors are selected from the 16 colors defined in the color look-up table. One color
with 16 bits can be of either RGB code or color bank code.

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Color Operation

Gouraud Shading, shadow, half-brightness, and semi-transparent color operations
can be designated by VDP1. Table 3.6 shows the types of color operations.

Table 3.6 Types of Color Operations

Gouraud Shading

Gouraud shading can be applied to parts drawn by RGB, and interpolates color
between polygon vertices which causes a flat surface to appear curved.

A surface can appear to be curved by giving brightness correction values to the four
vertices of a polygon and applying Gouraud shading within these four vertices.
Gouraud shading can be applied to polylines and lines as well. Figure 3.6 shows an
example of Gouraud shading.

TYPE

DESCRIPTION

Semi-transparent

A foundation at half brightness is added to the original at half
brightness. The result is drawn in the frame buffer.

Half-Brightness

An object at half the brightness of the original picture is drawn

in the frame buffer. The foundation cannot be seen because i
is written over and the brightness of the original is reduced to
half.

Shadow

The foundation at half-brightness is re-drawn in the frame
buffer. Here, a shadow of the character shape in the original
can be created. The character of the original is used only in th
shape of the shadow and color data is ignored.

Gouraud Shading

An object in the original picture to which Gouraud shading is
applied is drawn in the frame buffer.

Gouraud Shading

Semi-transparent

The brightness of an object in the original picture to which
Gouraud shading is applied is reduced to half, and foundation
at half-brightness is added. The result is drawn in the frame
buffer.

Gouraud Shading

Half Brightness

The brightness of an object in the original picture to which
Gouraud shading is applied is reduced to half, and the object i
drawn in the frame buffer.

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Figure 3.8 Gouraud Shading

Mesh Process

Mesh can be applied to all parts. A checkered pattern (every other dot) is drawn to
the part in which the mesh is applied.

0 1 2 3 4 5 6 7 8 9

0
1
2
3
4
5
6
7
8
9

: not painted

: painted

"X coordinate value + Y coordinate
value" is painted only for even
numbered pixels; odd numbered
pixels are skipped and not written.

Figure 3.9 Mesh Process

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Clipping

Clipping allows only the set display area to be drawn and cuts away any excess.
Clipping includes system clipping that sets the system draw area, and user clipping
that enables any setting by the software.

System Clipping

System clipping is always in effect while drawing. and the inside of the set area is
drawn (see Figure 3.10).

Lower Right Coordinate

System Clipping Area

(0,0)

System clipping can be designatedby
fixing the upper left coordinate (0,0)and
defining the lower right coordinate

Figure 3.10 System Clipping

User Clipping

User clipping can be selected by the software. Choose whether to make user clip-
ping effective for each part, or the inside or outside of the user clipping set area of
the effective area.

Lower Right Coordinate

Upper Left
Coordinate

(0,0)

User Clipping Area

User clipping area can be
designated by selecting the
verticies of the upper left and
lower right coordinates.

Figure 3.11 User Clipping

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Frame Buffer

· The frame buffer is divided into two screens, the display frame buffer and draw

frame buffer. Read/Write access from the SCU to the frame buffer is performed
only for the draw frame buffer. The display frame buffer becomes a back-end
bank and cannot be accessed.

· By reading the frame buffer, the read start coordinate and next dot to be read can

enlarge, reduce, and rotate the entire frame buffer surface by giving X and Y
direction displacement, which designates the location.

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3.4

VDP2

VDP2 determines priority of display of the scroll screens and the entire screen (in-
cluding sprites). Simultaneous display of scroll screens has been expanded to a
maximum of five screens. A screen can be moved up, down, left, and right, and
rotated. Priority (display priority order) can be programmably set on each character.

System Configuration

VDP2 has VRAM connected to it and color RAM built-in. Image data is defined
from the CPU through the SCU to VRAM and color RAM.

Data defined in VRAM is read according to settings of the register and becomes
image data of each scroll screen. This data, VDP1, as well as image data sent from
the external image circuits determine the display priority order according to the
register setting, then become display image data. Display image data is converted to
display color data and output to the TV (Figure 3.12).

CPU

SCU

VRAM

VDP1

VDP2

Color

RAM

External Image

Circuit

(optional)

Figure 3.12 VDP2 System Configuration

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Table 3.7 VDP2 System Specifications

Item

Specification

Remarks

TV Screen

· Horizontal Resolution

Select from 320, 352, 640, 704 pixels

· Vertical Resolution

Select from 224, 240, 256 pixels

(for non-interlace)

Select from 448, 480, 512 pixels

(for Interlace)

Vertical resolution of 256
pixels and 512 pixels are
for PAL only.

Character

· Character Size

Select from 1 X 1 cell and 2 X 2 cell

· Number of character colors

Select from 16, 256, 2048, 32768, and
16,770,000 colors.

Bit map format is also
possible.

Normal Scroll
Screen

· Max. no. of simultaneous screens is 4

· Scrolls horizontally and vertically

· Can line scroll

· Scrolls vertical cells

· Reduces to 1/4, enlarges to 256X

· Mosaic function

Rotation Scroll
Screen

· Max. no. of simultaneous screens is 2

· Can Enlarge, Reduce, Rotate

· Rotation parameter can be switched

inside screen

· Special Screen processing by

coefficient table

Normal scroll screen can
not be displayed when 2
screens are displayed

Windows

· Normal window 2 screens

· Sprite window 1 screen

· Line window possible

Priority

· Priority of each screen is programmable

· Priority can be switched in character

units and dot units

Screen Operation

· Color operation for up to 4 screens is

possible

· Color operation rate 32 steps

· Color offset function

· Shadow function

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Functions

VDP2 has a scroll function for controlling the display of the scroll screen, and a
priority function for determining the display priority order (Figure 3.13).

Scroll Functions

Magnify and Reduce

Rotation

Line Scroll

Vertical Cell Scroll

Mosaic Process
Window

Priority Functions

Determine Priority

Color Operation
Color Offset
Shadow

Figure 3.13 Scroll, Priority Functions

Scroll Functions

Scroll has a scroll screen for displaying pictures and windows for display control.

· Scroll Screen

Scroll screen includes a normal scroll screen that can change the number of
displayable screens, and a rotation scroll screen that can rotate a screen.

Table 3.8 shows the functions of the normal scroll screen and rotation scroll screen,
and number of character colors.

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Table 3.8 Scroll Screen Functions

· Enlarge/Reduce Function

Enlarge and reduce the entire screen horizontally and vertically. Reduced display
horizontally limits the number of screens.

· Line Scroll Function

Scroll up, down, right, and left each line as well as enlarge and reduce horizontally.
This creates the feeling of distance, such as the road of a driving game.

· Vertical Scroll Function

Scroll up and down in units of horizontal cells. It can create depth as in a vertical
scroll game.

· Mosaic Function

All scroll screens are divided horizontally and vertically, and the color of upper-left
dots in each area are displayed per dots in that area.

Function

Normal Scroll Screen

Rotation Scroll Screen

Screen 0

Screen 1

Screen 2

Screen 3

Screen 0

Screen 1

Enlarge/Reduce

1/4 X ~ 256 X

any factor

Rotation

yes

Line Scroll

yes

Vertical Cell Scroll

yes

Mosaic Process

yes

(only in horizontal)

Displays Bit Map

yes

Character Color
Number

Select from

256

2048

32768

16.77 mil.

Select from

256

2048

32768

Select from

256

Select from

256

Select from

256

2048

32768

16.77 mil.

Select from

256

2048

32768

16.77 mil.

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Area C

Area D

Area B

Area A

Horizontal direction
Mosaic Size

Vertical direction
Mosaic Size

The color of the dot in the upper
left corner of each area is used
in all dots within that area.

Rotation Function

· Rotation Display

The rotation scroll screen rotates along the coordinate axes (X, Y, Z axes) and the
screen axis vertical to the TV screen. Two surfaces can be displayed at the same
time.

Z axis

X axis

Y axis

X axis Rotation

Y axis Rotation

Z axis Rotation

Figure 3.14 Mosaic Pattern

Figure 3.15 Image Modification by Axis Rotation

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Figure 3.16 Image Modification by Screen Axis

· Rotation

Rotation calculation is done by the hardware according to designated parameters.
This means that rotation display can be done without straining the CPU load.
Twisted images can be displayed since coordinates can be calculated and different
values applied to each dot.

· Simultaneous Display by Screen Division

The image of two screens can be displayed by showing one screen of the rotation
scroll screen.

Scroll Screen Structure

The two scroll screen formats are the cell format and the bit map format. The cell
format, as in conventional home game devices, displays an arrangement of cells.
The bit map format, as with the personal computer, displays a picture that corre-
sponds to each dot on a screen.

· Cell Format

The cell format scroll screen is a picture pattern consisting of cells (eight horizontal
dots by eight vertical dots), character patterns (an arrangement of cells), pages (an
arrangement of character patterns), planes (an arrangement of pages), and maps (an
arrangement of maps). Figure 3.17 shows the structure of a cell format scroll screen.

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Cell

Page

Plane

Map

Character

Pattern

H8 dots X

V8 dots

H1 cell X

V1 cell

H2 cells X

V2 cells

32 X 32

64 X 64

character

patterns

(64X64 cells)

H1 page X

V1 page

H2 pages X

V1 page

H2 pages X

V2 pages

H2 plains X

V2plains

(Normal Scroll Screen)

H4 plains X

V4plains

(Rotation Scroll Screen)

NOTE: V = vertical

H = horizontal

Figure 3.17 Cell Format Scroll Screen

· Bit Map Format

The bit map scroll screen consists of a bit map pattern 512 dots or 1024 dots horizon-
tally and 256 dots or 512 dots vertically in size. Figure 3.18 shows the configuration
of the bit map scroll screen.

Bit Map

NOTE: V = vertical

H = horizontal

1 dot

H 512 X V 256 dots
H 512 X V 512 dots

H 1024 X V 256 dots

H 1024 X V 512 dots

Figure 3.18 Bit Map Scroll Screen and Data Setting Relationship

Windows

Windows are classified into three types depending on the way the area is designated
(coordinate designation).

· Normal Rectangular Window

Designated by two coordinate points: start and end.

· Normal Line Window

Designated by the start and end points of each line coordinate.

· Sprite Window

Designated by sprite character patterns.

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Inside

Window

Inside

Window

Outside

Window

Outside

Window

Outside

Window

TV Screen

Normal Rectangle Window

Normal Line Window

Sprite Window

Inside Window

Figure 3.19 Windows

Priority Functions

The display priority order of sprites and scroll screens is determined by a 3-bit
priority number. The sprite priority number can set a maximum of eight values; one
of which is designated by character units.

Determining Priority

The scroll screen priority number is designated in normal surface units. (This can be
changed by character units or dot units using special priority function.)

transparent

Top Image

Second Image

Third Image

Priority
Number=6

Priority
Number=4

Priority
Number=2

Priority
Number=1

Figure 3.20 Priority Function

· Special Priority Function
Priority numbers that correspond to each scroll screen can be changed by character
or dot units. This function the priority of only the area within the scroll screen to be
changed, which causes one scroll screen to appear like as more than one screen.

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Color Calculation Function

By adding multiple screens of color data, the color calculation function produces an
effect that makes the back screen appear to be seen through the front screen. This is
normally done by two screens, the top image and the second image, but can be done
with up to four screens if the expanded color calculation function is used.

transparent

Priority Number = 4

Priority Number = 2

Back

Screen

Figure 3.21 Color Calculation Function

· Line Color Screen Insert
The line color screen forces the top image part of the designated screen to be inserted
as the second image, and induces color calculation. The pre-inserted second image
becomes the third image in the area of the inserted line color screen, and the third
images drops one to become the fourth image. Figure 3.22 shows insertion of the
line color screen.

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top image

second image

third image

fourth image

line color screen

back screen

transparent

screen the line color screen
has been inserted into

Priority number =6 Priority number =4

Priority number =2

Priority number =1

Figure 3.22 Insertion of the Line Color Screen

Shadow Function

The shadow calculation function adds a shadow in the shape of the sprite character
on all screens.

Frame Buffer Data

Scroll Screen

Output Screen

Shadow Sprite

Normal Sprite

transparent

Figure 3.23 Shadow Function

· Blur-Calculation Function

The blur-calculation function adds the horizontal color data of one designated screen
at a fixed rate, and is able to create an effect of a blurred distant background.

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Screen A

Screen B

Screen C

transparent

Screen A

Screen C

Screen A

Screen B

Priority number = 6

Priority number = 4

Priority number = 2

Screen designated

to be blur-calculated

Top Image

Second Image

Blur-Calculated

Screen C

Screen B

Color Operation

Display Image

Color Function used in Screen C

Replaced as a result of
blur-calculation on
screen C

Screen B

Second Image

Screen C

Blur-Calculated

Screen C

The sum of color data is forced to be as second image in the area where the top or
second image is the designated screen. The blur-calculated picture can be displayed
by performing color calculation on the second and top images.

Color Offset Function

The color offset function displays and adds (or subtracts) the offset value for the
screen color data, and is used in fade-in and fade-out. Designate whether to use the
color offset function in each screen.

Figure 3.24 Blur-Calculation Function

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3.5

SCSP

SCSP is custom sound LSI that unites PCM (FM) sound generation with a sound
only DSP. The goal of the audio function is to provide higher tone quality with all
interfaces for increasing expandability. Capable of creating many sounds, the opera-
tion part provides a performance that rivals that of a synthesizer. The DSP can
create multiple sound fields, such as each type of sound field play as well as the
special effects of 3D sound positioning.

System Configuration

The main CPU, sound CPU, sound memory, and D/A converter are all connected to
the SCSP. In the sound system, these can operate independent of the main processor.

The main CPU transfers the sound (CPU, DSP) program and wave form data to the
SCSP sound memory through the SCU. The sound CPU transfers wave form data to
the register inside the SCSP. SCSP reads delayed data for producing sound memory
wave form data as well as the effect. The audio is mixed and output as sound
through a D/A converter.

SCU

Sound CPU

MC68EC000

S C S P

D/A Convertor

Sound Memory

(DRAM)

Interface

PCM(FM)

DSP

MIXER

CPU Program

PCM Sound Data

DSP Delayed Data

Figure 3.25 SCSP System Configuration

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System Specifications

Table 3.9 shows the SCSP system specifications.

Table 3.9 SCSP System Specifications

Functions

The main functions of the SCSP are listed below.

· Frequency control
· Volume control
· FM operation
· LFO (Low Frequency Oscillator) modulation function
· Digital / Audio mixing
· Effect from DSP (reverb)

Item

Specifications

Remarks

Sampling Frequency

· 44.1 KHz

Audio Synthesis System

· PCM, FM Format

Audio Process Slot Number

· 32 slots

Wave Form Data Format

· 8-bit, 16-bit formats

2'S complement

Each function type

· Envelope

· Loop Process

· LFO

Effect from internal DSP

· Reverb, Chorus, etc.

Other functions

· DMAC ......................... 1ch

· Timer ............................ 3ch

· MIDI ............................. IN/OUT each 1

· External D/A Input ....... Stereo1 system

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Effect

Because the SCSP DSP can create multiple sound fields, it is possible to have differ-
ent settings for BMG sound and game sound.

For example, in a racing game, reverb would be applied to the concert grounds as
BGM while reverb could be applied at the same time in producing an atmosphere
inside a tunnel for the game.

roarrrrr

Reverb applied to
create a tunnel
atmosphere

Effect applied to
BGM (CD voice)

Figure 3.26 Tunnel and BGM Reverb

In the DSP, the effect can be applied to CD audio because the audio signals from the
sound generator, and sound signals from the CD are input. Because the CD output
level can be controlled through the SCSP, the sound signal from the sound generator
and CD can be balanced and therefore the sound from the sound source will still be
audible without being "hidden" by the CD sound. Thus, concealing the CD sound
will not conceal the sound of the sound generator.

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Sound Position

With a high performance digital mixer, the SCSP can control the positions of all
sounds in real time. As a result, effective sounds can be produced on the screen with
character positions. This process can be done by the DSP as well. In this case, when
the character moves slowly, the sound orientation will move smoothly because more
intricate settings can be made. A sense of depth (distance) can be created by adding
reverb to this positioning.

Sense

ofdistanc

Fixed Position (pan)

pachinn

A sense of distance can be created by
changing the echo according to the
distance. This includes fixed positions (pan)
also.

Figure 2.27 Tennis Game Example

Besides this, indoors, outdoors, and wide open spaces can be expressed depending
on the type of reverb. Also, the type of reverb can also be set for all conditions, such
as a hall, stage room, steel plate, etc.

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3.6

CD-ROM

The CD-ROM system has its own CPU and buffer RAM, and can operate indepen-
dently of the main system. By setting in advance conditions from the main system,
flexible buffer management that suits the application configuration is attained.

System Configuration

The CD-ROM system operates only by giving commands through CD I/F from the
main system. The sub-CPU interprets commands from the main system, controls the
CD-ROM drive and CD buffer, reads data, and plays video and audio. Audio and
video playing employs the MPEG international video compression standard, and
uses the exclusive "MPEG/Video LSI" as well as "MPEG / Audio LSI." The system
configuration is shown in Figure 3.28.

The sub-CPU, CD buffer, frame buffer, C/D I/F are connected to the MPEG / Video.
Compressed image data is received from the CD buffer and regeneration image data
is written (drawn) to the frame buffer. Drawn frame buffer data carries out the effect
according to register settings and displays in the display device through VDP2 the
controls screen display; or it is transferred to VDP1 and VDP2 VRAM through CD I/
F and SCU.

MPEG / Audio receive compressed audio data from the CD buffer and outputs
stereo 1ch audio data. This audio data is output through the SCSP as sound.

SCSP

VDP2

SCU

CD I/F

MPEG
Video

Frame
Buffer

CD Buffer

CD Drive

MPEG
Audio

SubCPU

(SH-1)

Audio

Image

A-bus

B-bus

Speakers

<CD-ROM System>

Figure 3.28 CD-ROM System Configuration

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CD-ROM system specifications are shown in Table 3.10, and CD drive specifications
are shown in Table 3.11.

Table 3.10 CD-ROM System Specifications

Table 3.11 CD Drive Specifications

Item

Specifications

Remarks

G/A Register width

16 bit

Seek Time

400 msec (1/3 access time, double speed
rotation time)

Rotation Speed

Normal time: 620~1680 rpm

2X speed: 1240~3360 rpm

CD Read Speed

Normal speed: 75 sectors/sec = 150KB/sec

2X speed: 150 sectors/sec = 300KB/sec

Tray Open & Close Method Top loading

Memory Capacity

RAM 512KB (for CD buffer) ROM 64KB (for

BIOS) RAM 512KB (for MPEG)

Data Transfer Speed

Max. 8MB/sec, max. 4MB/sec while MPEG is
in operation

LED

Flashes according to CD operation status

Item

Specifications

Remarks

CD Play

Track/Index designation play

Frame address (in absolute time) designation
play

Play restarts (Cancels pause, controls pick-up
movement)

Repeat play

able to control CD-DA and CD-ROM by
commands of identical format

Scan regeneration

Retrieve subcode

Other

Corresponds to Multi-session

Corresponds to Emphasis

Decode and error correction corresponding
to CD-ROM XA

(Subheader recognition, ECC process, Read
retry process)

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Functions

The main functions of the CD-ROM system are shown below.

· Stream select
· Parallel processing
· MPEG functions

-Video play
-Pause screen play (high detail, JPEG)
-Window function
-Visual effect function
(mosaic, shading, Chroma key, fade in / fade out)
- play function
-Pause, freeze, frame feed, slow motion
-MPEG buffer function

CD-ROM system first stores data read from the CD-ROM to the CD buffer. The
stored data reads/writes to the main system or MPEG in response to commands
from the main system. Figure 3.29 shows the data flow of the CD-ROM system.

CD-ROM

MPEG Buffer

MPEG Decoder

CD buffer

(buffer section)

MPEG Frame Buffer

VDP2

Data transfer Register

Host

MPEG Register

Play

Read Write

CD Read = Read

Copy Move

Write

Decode

Display

Image Data

Retrieve

Write

Retrieve

CD Block

Host

Write

Figure 3.29 CD-ROM System Data Flow

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Stream Select

Data flow from the CD-ROM is called a stream. A stream has audio data, image
data, and program data. The stream select function selects the classification of data
and sends it to the main system and MPEG (Figure 3.30). Control content of the
stream select function is shown below.

· Stream data accumulates in the CD buffer and is selected in response to the

data classification.

· Data from devices such as a CD-ROM and MPEG decoder are controlled

uniformly.

· Stream select conditions are set by command.

CD-ROM XA

Select

Buffer

Video

Audio

Main

System

V : Video
A : Audio
D : Data

Data

D A V D A V

Figure 3.30 Stream Select Function

Parallel Processing

The CD-ROM system reads streams, it also selects streams and controls the CD drive
independently of the main system. Further, parallel processing can be done since
more than one stream selection mechanism is set.

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MPEG Function

MPEG plays animation with sound added.
Image data is compressed to 1/50 and audio data is compressed to 1/10 before
being played. Therefore, 74 minutes can be recorded on a CD. An exclusive LSI
allows a game with animation (movie) of high image quality to be played without
overloading the CPU.

MPEG / Video Function

Saturn's MPEG/Video has various special functions that are exclusively customized
for Saturn.

Window Function

As shown in Figure 3.31, this function cuts out part of the image played and displays
it at any size on the TV screen. This function allows the display position of the
MPEG play image and display size to be changed, to select and display one of sev-
eral screens, and zoom in, and zoom out.

Image from VDP1, 2

Expressions
such as "open
window" are
allowed

Animation (object 1)

Animation (object 3)

Animation (object 2)

Animation (object 4)

MPEG Play Images

Figure 3.31 Window Function

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Original Image

24 bit, full color

Mosaic

Mosaic size horizontal direction

Mosaic size
vertical direction

The color of the dot in the upper left
corner of each area is used in the
dots of the entire area.

Shading

Displays average of right, bottom,
and lower right dots

Horizontal Vertical
Interpolation

Displays average of 4 corner dots

Interpolation Function

The MPEG play image is a maximum 352 X 240 dots horizontally, while vertical
interpolation can be displayed at a resolution of a maximum 704 X 480 dots to pro-
vide a smooth display with less flickering.

Shading Function

Displays a color data average of four dots that adjoin horizontally and vertically, and
can produce a distant background shading effect.

Figure 3.32 Interpolation, Shading, Mosaic Functions

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Mosaic Function

The MPEG play image is divided horizontally, vertically, and at a designated size.
The color of the dot in the upper left of each area indicates the color of all dots in
that area. Horizontal and vertical can be independently designated up to a full
screen size.

Fade Function

This is a display function that gives magnification to the coloring signal and screen
brightness, and is used for fade-in and fade-out. Because this isn't a method of
adding and subtracting offset values, only the brightness can be correctly changed.
Further, by changing the coloring signal, the monochrome display or displayed
color can be deepened.

Chroma Key

As shown in Figure 3.33, this function plays animation that has transparent dots.
The chroma key is a technique of filming an object in front of a blue background,
taking out all parts that are not blue, then placing those parts in a separate picture.
MPEG animated images can be used only on background with the existing MPEG
LSI, but the chroma key function lets Saturn superimpose and display MPEG ani-
mated images on sprite and scrolls.

TV Screen

Blue Background

MPEG Screen

Sprite Screen

Scroll Screen

Figure 3.33 Chroma Key Function

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Screen Retrieve Function

Animated images played by MPEG are retrieved to the main system by this func-
tion, and are handled as sprites, used as texture data, and displayed using the VDP1
and VDP2 functions. Furthermore, this function playing of multiple animations.

The amount of MPEG animated data is 50 times the amount of data from a CD, and
because the transfer speed is faster than the transfer speed from a CD buffer, this
function can be used to rewrite texture data at high-speeds.

High Detail Pause Function

This function displays a 704 x 480 dot high detail pause screen. Full color high detail
images cannot be displayed by the main system (full color is up to 352 x 240 dots),
but if the high detail pause function is used, an image with Saturn's maximum
number of color can be displayed.

Pause Function, Freeze Function

The pause function can pause the animation at any frame, and can run in slow
motion as well as frame by frame.

The freeze function memorizes animation at any frame (image memory) and allows
strobe playback.

Branch Play Function

MPEG accumulates compressed image data in the CD buffer memory and plays
animation during CD seek (track search). As a result, animation will continue play-
ing even when jumping to another animation track. The screen will not pause as
with LD.

In MPEG, the branch playback where branch point cannot be determined is
achieved. Furthermore, loop play, which repeats the same animation, can be done.

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MPEG / Audio Function

Audio data played by MPEG/Audio is sent to the SCSP by the same path as a CD-
DA (Music CD), and can perform various effects.

Variable Compression Rate

The compression rate can be selected in response to the use; you can choose from a
compression of 1/3.5 ~ 1/21. If the 1/21 compression is used, 50 hours of audio can
be recorded on a CD. Even with huge RPG and ADV, all dialogue and narration can
be performed with audio.

On Memory Play Function

MPEG / Audio can compress to 1/3.5 ~ 1/21. When using half of the
4 Mbit of CD buffer memory for MPEG/Audio by using a compression of 1/21, 64
seconds of audio can be played without accessing the CD. As a result, audio play
can be done without waiting. Furthermore, several short dialogues can be con-
nected for long conversations.

Corresponding Standards

Table 3.12 shows the standards that correspond to the CD-ROM system.

Table 3.12 Corresponding Standards

Standard

Description

CD-DA

The standard name of sound entered on a CD is base on the REDBOOK
international standard. Sampling frequency 44.1 KHz, quantumization bit
16-bit stereo.

CD-G, CDEG

Records data such as graphics data in the music CD format area.

Employs 16 color display and CD-DA sound quality.

CD-ROM

The standard has been established to enable recording of computer data
with the same physical format as a music CD (CD-DA). Based on YELLOW
BOOK international standard.

CD-ROM XA

This is an expanded CD format with a record format that makes possible
interleave recording for concurrent playing of video and audio.

(electronic book)

CD-ROM software record format that is employed by the Sony Data Discma
(electronic book player).

Photo-CD

System that displays photographs through a monitor such as a television.

Up to 100 photographs can be recorded on a CD; the same photograph ca
be enlarged and reduced.

Video CD

(Karaoke CD)

Records video that has been compressed by MPEG. A maximum of 74
minutes can be recorded on a CD, and a maximum of 2000 high detail pau
pictures can be played.

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3.7

Other Items

SMPC

SMPC resets the entire Saturn system when the reset button is pressed or the power
turned on. The command from SH-2 turns on or off the peripheral LSI inside of
Saturn, sets and retrieves the calendar and time, and collects data from peripherals.
The clock change command switches between a horizontal resolution of 320 or 352
dots.

Power On Reset

Reset Switch

SCU

VDP1

VDP2

SCSP

PLL

MC68EC000

PAD

SH-2

(master)

SH-2

(slave)

Sound Reset

System Reset

NMI

RES

NMI

*Switch

Inside Saturn

command

data

reset

clock switch

SMPC

RES

(* Peripheral I/O terminal can be directly controlled from the SH-2 side.)

Figure 3.34 SMPC System Configuration

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Functions

The main functions of SMPC are shown in Table 3.13.

Table 3.13 SMPC Functions

PAD

Table 3.14 shows the digital PAD specifications for Saturn.

Table 3.14 Saturn Digital PAD Specifications

RTC

(Real Time Clock)

· Sets and retrieves time and date form SH-2

· Battery back-up function

· Automatically revises the date, day of the week,

hour/minutes/seconds.

S M

(System Management)

· ON/OFF of Sound CPU

· ON/OFF of master SH-2 and slave SH-2

· Controls system reset

· Switches clocks (PLL switch)

· Power ON reset

· When Saturn is ON, Saturn system is reset by

pressing the

reset switch.

(Peripheral Control)

· Automatically collects peripheral data such as

control pad

and mouse.

· Supports Megadrive and Genesis peripherals (3

button, 6 button, 4 player adapter, mouse).

PAD Type

Specifications

Saturn Standard PAD

Buttons: up, down, left, right, A, B, C, X, Y, Z, L, R, start.

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INDEX

Bit map format 33
Branch play function 49

C3 iii
Cartridge I/F 9
CD-ROM 42
CD-ROM drive 10
CD-ROM drive specifications 43
CD-ROM system data flow 44
CD-ROM system configuration 42
CD-ROM system specifications 42
Cell format 32
Cell format scroll screen 33
Chroma key function 48
Clipping v, 25
Color bank method 22
Color calculation function 35
Color look-up table 22
Color offset function 37
Color operation 23
Compression rate variation 50
Configuration of Color bank method 22
Corresponding standards 50
CPU 6, 11
CPU specifications 11

D/A converter 10
Determining priority 34
Display (VDP1) 21
Double density interlace 21
DSP iii

Effect 40
Effect Data v
Encode 9

Fade function 48
Regular sprite 19
Frame buffer 26
Freeze function 49
Functions (CD-ROM) 44
Functions (SCSP) 38
Functions (SCU) 15
Functions (VDP1) 18
Functions (VDP2) 29

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Gouraud shading iii, 23, 24

Hardware specifications <main system> 6
Hardware specifications <sub system> 6
High detail pause function 49
High Resolution iv

Image change by image axis 32
Image change by rotation axis 31
Image change by screen axis 32
Interlace iii, 21
Interpolation function 47
Interpolation, Shading, Mosaic Functions 47
Interrupt control (SUC) 15
IPL v

Line 21
Line and texture parts 21
Line color screen insert 35, 36
Line scroll function 30

Enlarge/Reduce function (VDP2) 30
Enlarge/Reduce Sprite (VDP1) 19
MC68EC000 8
Mesh process 24
Mosaic function 30, 48
Mosaic pattern 31
MPEG/Audio function 50
MPEG/Video function 46
MPEG functions 46
MPEG iv, 10

Normal line window 33
Normal rectangular window 33

On memory play function 50
Operating frequency (SCU) 15

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PAD 52
PAD I/F 9
PAL format v
Parallel processing 45
Parts classification 18
Parts iv
Perspective iv
Pause function 49
PCM iv
Pixel iii
PLL v
Polygon 21
Polyline 21
Priority function 34

RAM 6, 8
Related manuals ii
Reverb v
RGB code generation 6, 8
Rotation calculation 32
Rotation display 31
Rotation function 31

Saturn digital PAD specifications 52
Screen retrieve function 49
Scroll function 29
Scroll screen 29
Scroll screen configuration 32
Scroll screen function 30
Scroll, Priority functions 29
SCSP 9, 38
SCSP system configuration 38
SCSP system specifications 39
SH-2 8
Shading calculation function 36, 37
Shading function 47
Shadow function 36
Simultaneous display by screen division 32
Single density interlace 21
SMPC 8, 12, 51
SMPC functions 52
SMPC system specifications 51
Special priority function 34
Sprite iv
Sprite window 33
Stream select mechanism 45
Stream selection 45
System clipping 25
System configuration (CD-ROM) 42
System configuration (SCSP) 38

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System configuration (VDP2) 27
System configuration 7
System specifications (SCSP) 38

Texture mapping iv
Texture part 19
Transformed sprite 20
Tunnel and BGM reverb 40
Types of color calculation 23

User clipping 25

VDP1 9, 16
VDP1 system configuration 16
VDP1 system specifications 17
VDP2 9, 27
VDP2 system configuration 27
VDP2 system specifications 28
Vertical scroll function 30

Window 33, 34

Window function 46