2. System

This section describes the system block diagrams and hardware block information for both SNAKE and CTR.

2.1. System Block Diagram (SNAKE)

Figure 2-1 shows an overview of the SNAKE system.

Figure 2-1. System Block Diagram (SNAKE)

The 800 pixels for stereoscopic display mode consist of 400 pixels each for the left and right eyes.

The items with a red background in the diagram are newly added specifications in SNAKE. Items with an orange background have changed from CTR.

 

Note:

The LCD screen size and other specifications differ depending on the hardware variation. For information about the specification differences, see 3DS Overview – General.

2.2. System Block Diagram (CTR)

Figure 2-2 shows an overview of the CTR system.

Figure 2-2. System Block Diagram (CTR)

The 800 pixels for stereoscopic display mode consist of 400 pixels each for the left and right eyes.

Note:

FTR (Nintendo 2DS) has different specifications than CTR for the number of speakers and the upper screen. For information about the specification differences, see 3DS Overview – General.

Application developers do not need to consider the differences between CTR and FTR.

2.3. SoC

The system-on-chip (SoC) includes the main components of the CPU, GPU, DSP, and VRAM all on one chip. The specifications of each are as follows.

2.3.1. CPU

This is an ARM11 MPCore processor with multiple cores and their related vector floating-point (VFP) coprocessors.

  SNAKE CTR
Processor Core ARM11 MPCore
Operating Frequency 268 MHz or 804 MHz 268 MHz
L1 cache 4-way set-associative (per core)

Core 0-1:
  16 KB for instructions, 16 KB for data

Core 2-3:
  32 KB for instructions, 32 KB for data

Core 0-1:
  16 KB for instructions, 16 KB for data

L2 cache

16-way set-associative

(Shared by all cores. 2 MB shared command/data.)

None
Endianness Little-endian

 

CTR has two CPU cores (Core 0 and Core 1). SNAKE has four CPU cores (Core 0 through 3). An application can use CPU Core 0 exclusively, while the remaining cores are used by the system. The core used exclusively by the application is called the application core and the cores used by the system are called the system cores. Each CPU core is used as follows.

CPU Core Usage
Core 0 Application
Core 1 System (but applications can use up to 30%)
Core 2 Unused (reserved for system)
Core 3 System (controls the Super-Stable 3D feature)
Note:

Although part of the system core can be used by the application, there are disadvantages such as a negative effect on background processes.

2.3.2. GPU

This includes a graphics core developed by Digital Media Professionals Inc. (DMP).

Because graphics processing is handled by the framebuffers, the BG or OBJ concepts used for the Nintendo DS do not apply.

Graphics Core PICA graphics core
Operating Frequency 268 MHz
Architecture Framebuffer architecture
Shader Vertex (programmable), pixel (not programmable)
Graphics Features

OpenGL ES 1.1-based fixed pipeline + independent extensions (partially equivalent to OpenGL ES 2.0)

Frequently used 3D graphics processes are built into the hardware.

2.3.3. VRAM

This includes two 3-MB video memory modules, which are read/write accessible only from the GPU. There is no difference in the performance of the two memory modules.

This is generally used as the location for the color buffers, depth buffers (Z buffers), and stencil buffers, and for textures and vertex buffers that are frequently used.

VRAM is independent of the main memory and cannot be written to directly by the CPU.

2.3.4. Sound DSP

The CTR system comes equipped with a digital signal processor (DSP). Unlike the DSP in the TWL, the CTR's DSP cannot be used for other processing.

Number of Channels 24 ch
Sampling Rate Roughly 32,728 Hz (precisely, Fs = 16756991 * 16 / (32 * 256) = 32,728.49805… Hz)
Parameter Update Interval Roughly 4.889 ms (precisely, T = 160 / Fs = 4.888705… ms)
Sampling Format DSP ADPCM / PCM8 / PCM16
Resampling Polyphase filter / linear interpolation / disabled
Number of AUX Buses 2

2.4. Main Memory

Each system has the following memory space available.

  SNAKE CTR
Main Memory

124 MB

(Development hardware has 178 MB.)

64 MB

(Development hardware has 96 MB.)

Texture and vertex buffers may also be located in main memory and referenced directly from the GPU.

For more information about the memory map, see 3.1. Memory.

2.5. Operating Modes

The SNAKE hardware has two modes of operation: a standard mode that is equivalent to CTR, and an extended mode that is unique to SNAKE.

The following table lists the performance differences between standard mode and extended mode.

Table 2-1. Differences Between Standard Mode and Extended Mode
  Standard Mode Extended Mode
CPU Operating Frequency 268 MHz 804 MHz (3x)
CPU L2 Cache Disabled Enabled (2 MB)
Main Memory Size 64 MB 124 MB

2.6. LCD

The system has two LCD screens.

    SNAKE CTR (SPR) FTR
Upper Screen Screen size

3.88 inches

XL is 4.88 inches.

3.5 inches

SPR is 4.88 inches.

3.5 inches

Resolution

(3D display)

400 × 240 pixels

800 × 240 pixels (with one pixel for the left eye and one for the right displayed in the same size as a single pixel in normal 2D display)

Color depth 8-bit RGB for approximately 16.77 million colors
LCD type Semi-transmissive (anti-glare)
Backlight

Built-in active backlight (controlled by turning power-saving mode on and off)

Brightness can be adjusted while the HOME Menu is displayed.

3D display By setting the mode and designing an application to support it, an application can support autostereoscopic display (stereoscopic 3D without glasses). None
Lower Screen Screen size

3.33 inches

XL is 4.18 inches.

3.0 inches

SPR is 4.18 inches.

3.0 inches
Resolution 320 × 240 pixels
Color depth 8-bit RGB for approximately 16.77 million colors
LCD type Semi-transmissive (no anti-glare)
Backlight

Built-in active backlight (controlled by turning power-saving mode on and off)

Brightness can be adjusted while the HOME Menu is displayed.

Touch panel Resistive film (No multi-touch. Input coordinates can be obtained in LCD pixels.)
Warning:

Stereoscopic display does not work when the system is held vertically (with the longer side of the LCD screens vertical).

Note:

For more information about stereoscopic display, see the 3DS Programming Manual: Advanced Graphics.

2.7. Memory Devices

2.7.1. Game Card Slot

The Game Card slot accepts the following Game Cards.

  3DS Only DS Only
DSi-Compatible
DSi Only
SNAKE
CTR
Note:

It does not have a Game Pak (GBA) slot.

2.7.1.1. Nintendo 3DS Game Cards

Nintendo 3DS Game Cards can be accessed at higher speeds than TWL/NITRO Cards, and security features have also been revamped.

Two types of cards are available: CARD1 and CARD2. Current specifications support a CARD1 ROM capacity of up to 4 GB (32 gigabits). A backup memory capacity of either 128 KB (1 megabit) or 512 KB (4 megabits) is supported. CARD2 provides a total ROM and backup memory capacity of up to 2 GB (16 gigabits).

The system uses some of the capacity of both the ROM and backup memory. For more information, see 3.2. Nintendo 3DS Game Cards and 7.3. Save Data.

2.7.2. System NAND Memory

Each system has the following amount of internal NAND memory. System NAND memory is used for saving data such as preinstalled application data.

  SNAKE CTR
Capacity 1.3 GB 1 GB

2.7.3. SD/microSD Card Slot

Each system includes a microSD or SD card slot that supports the following media types.

The system provides a means of accessing some files using dedicated libraries (for example, SoundDB and ImageDB). Applications (specifically, downloadable applications other than Nintendo DSiWare) can be started directly from an SD card.

  SNAKE CTR
Supported Media

microSD Memory Card
microSDHC Memory Card

(microSDXC Memory Cards are not supported.)

SD Memory Card
SDHC Memory Card

(SDXC Memory Cards are not supported.)

2.8. Input Devices

2.8.1. Key Input

  SNAKE

CTR

SPR

FTR Comments
+Control Pad Yes  
A, B, X, and Y Buttons Yes

When the X Button on SNAKE is pressed with considerable force, downward movement might be detected on the C Stick. To avoid problems, we recommend the following workarounds in applications that use the C Stick.

  • Do not assign press-and-hold operations to the X Button.
  • Do not read values from the C Stick in scenarios where the X Button is held down.
  • Adjust the sensitivity of the C Stick.

More force is required to reproduce this issue on the development hardware and the new Nintendo 3DS than on the new Nintendo 3DS XL.

L/R Buttons Yes  
ZL/ZR Buttons Yes Available when Circle Pad Pro is connected. None The ZL and ZR Buttons on SNAKE are compatible with the ZL and ZR Buttons on the Nintendo 3DS Circle Pad Pro. Applications can handle them as if SNAKE were a CTR system that is always equipped with the Circle Pad Pro.
Circle Pad Yes  

C Stick/

Right Circle Pad

Yes Available when Circle Pad Pro is connected. None The C Stick on SNAKE is compatible with the Right Circle Pad on the Nintendo 3DS Circle Pad Pro. Applications can handle them as if SNAKE were a CTR system that is always equipped with the Circle Pad Pro.
START or SELECT Yes SELECT has been kept for backward compatibility with Nintendo DS software, and any SELECT press is interpreted by 3DS applications as identical to a START press.
HOME Button Yes

Activates the HOME Menu.

This input cannot be used by the application for gameplay purposes.

POWER Button Yes

Controls power features. To prevent unintended operation of the button, the button does not react to momentary presses. Holding it down for a set period of time begins forced shutdown.

On SNAKE hardware, the POWER Button can be pressed while the system is closed.

This input cannot be used by the application for gameplay purposes.

Wireless switch None Yes None

On SNAKE and FTR, wireless communication is enabled and disabled from the HOME Menu.

This input cannot be used by the application for gameplay purposes.

Open/close detection sensor/

Sleep Switch

Open/close detection sensor Sleep Switch

The open/close detection switch detects whether the system is open or closed. FTR cannot be closed, so it includes a sleep switch "slider" instead of an open/close detection switch.

This input cannot be used by the application for gameplay purposes.

Sound volume Yes

Equipped with a volume slider.

This input cannot be used by the application for gameplay purposes.

3D Depth Slider Yes None

Adjusts parallax for stereoscopic display.

This input cannot be used by the application for gameplay purposes.

2.8.2. Accelerometer

The CTR system includes an accelerometer in the base of the system that measures acceleration on each of the three axes. This can be used by applications. The accelerometer range is approximately 1.8 G in both directions on each axis, with noise when stationary of up to ±0.02 G, sensitivity of approximately 0.002 G, and a sampling rate of 100 Hz (theoretical value for the device).

2.8.3. Touch Panel

The CTR system has a touch panel over the lower LCD, just like the Nintendo DS/DSi.

The touch panel uses resistive film technology for single-point touch functionality similar to the Nintendo DSi. As with previous systems, input coordinates can be obtained in terms of LCD pixels.

2.8.4. Microphone

The monaural microphone is located to the side of the group of buttons at the bottom of the lower screen. Performance is equivalent to the microphone on the Nintendo DSi. As with the Nintendo DSi, the microphone gain can be adjusted from 10.5 dB to 70.0 dB in increments of 0.5 dB.

Sensitivity variations between individual microphones are within 0.5 dB (1.06x).

2.8.5. Cameras

The CTR system has one inner camera and two outer cameras (left and right), with the same specifications as the ones used on the Nintendo DSi system. You can either use both outer cameras at the same time or the left outer camera and the inner camera at the same time, but it is not possible to use all three cameras at the same time.

The main specifications of the cameras are as follows.

Aperture F2.8 (fixed).
Angle of view See the following table (when photographing at maximum resolution).
Photographable range 20 cm to infinity. (Pan focus. Not equipped with a macro switch.)
Maximum resolution VGA
Maximum frame rate 30 fps (fps: frames per second)
Output format YCrYCb (can also output to RGBA8888, RGB888, RGB565, and RGBA5551 formats by use of the separate YUV to RGB circuit).

 

 

Minimum

Average

Maximum

Diagonal

63.0°

66.0°

69.0°

Horizontal

52.2°

54.9°

57.6°

Vertical

40.4°

42.6°

44.8°

2.8.6. Gyro Sensor

The CTR system is equipped with a triaxial gyroscopic sensor in the bottom half of the system that can detect when the system is tilted and the speed of rotation. The sensor can measure up to ±1,800 degrees per second (DPS), with noise when stationary of up to ±2.28 DPS, sensitivity of 0.07 DPS, and a sampling rate of 100 Hz.

2.9. Output Devices

2.9.1. Speakers

CTR, SPR, SNAKE, and CLOSER have stereo speakers located to the left and right of the upper screen. FTR has a single monaural speaker located to the upper-left of the upper screen.

The following figure shows the sound pressure frequency characteristics of the CTR, SPR, FTR, SNAKE, and CLOSER speakers.

Figure 2-3. Sound-pressure Frequency Characteristics of the CTR (SPR/FTR/SNAKE/CLOSER) System Speakers

Acoustic input: -6dBFs [dBspl] [Hz] SPR CTR FTR

2.9.2. Audio Jack

The system comes equipped with a stereo output mini-jack. Unlike the Nintendo DS/DSi, there is no microphone jack.

Headsets that include a microphone are not supported.

  SNAKE CTR SPR FTR
Audio Jack location Front and center of the lower half of the system Front left of lower half of system

2.9.3. LEDs

The system comes with LEDs to indicate the camera state, battery level, charging status, wireless status, 3D display, and notification status.

Each platform has the following LEDs.

  SNAKE CTR SPR FTR
Camera status None Yes Yes None
Battery Yes Yes Yes Yes
Charging Yes Yes Yes Yes
Wireless Yes Yes Yes Yes
3D Display None Yes None None
Notifications Yes Yes Yes Yes

2.10. Communication Devices

2.10.1. Wireless Communication Module

The CTR system has a wireless communication module that transmits in the 2.4 GHz band.

Communications features can be broadly classified as foreground, such as when an application explicitly uses communications features, and background, such as when the system is engaging in automatic communications.

For more information about wireless communication, see the 3DS Programming Manual: Wireless Communication.

  • Foreground communication
    • Infrastructure communication
    • Local communication
    • Download Play

 

  • Background communication
    • StreetPass
    • Download tasks
    • Presence features

2.10.2. Infrared Communication Device

The CTR system comes with an infrared transceiver and an infrared communication device.

2.10.3. Near Field Communication (NFC)

A contactless near field communication (NFC) antenna is located below the lower screen panel for SNAKE.

2.11. Other

2.11.1. Real-Time Clock (RTC)

This keeps and measures time.

2.11.2. Compatibility With the Nintendo DSi

The CTR system maintains compatibility with the Nintendo DSi and supports DS Download Play.


CONFIDENTIAL