CTR CPU B

G 0? CS1 ? ? D5 D2 RST CLK G G X X 3v3 3v3 3v3 ? ? ? IRIRQ ? ? G
1? 2? CSx CSy ? D6 D3 D0 IRQ CS1 G G G G 3v3 3v3 G ? ? ? ? ? ?
3? ? ?
3v3 D7 D4 D1 DET CS2 G G G 3v3 3v3 G 3v3 3v3 3v3 ? ? ? ? ? IRTX ? ? ?
CLK D0 G 1v2 3v3 G 1v2 3v3 G 1v2 G G 1v2 3v3 G 1v2 3v3 G 1v2 3v3 G 1v2 3v3 G ? ? ?
D1 D2 D3 3v3 1v2 ? ? ?
CMD IRQ WP 1v2 1v8 ? ? ?
CLK D0 G 3v3 G 3v3 G 1v2 G 3v3 G 1v2 G 3v3 G 1v2 G 3v3 G G ? ? ?
D1 D2 D3 3v3 G 3v3 G 3v3 G 3v3 G 3v3 G 3v3 G 3v3 G 3v3 G 1v2 1v2 ? ? ?
CMD 1v2 1v2 G 1v2 G 1v8 ? ? ?
? ? ? G G 3v3 G 1v8 G ? ? ?
? ? 3v3 3v3 G 1v2 G 1v2 ? ? ?
1v2 G 3v3 G 1v8 1v8 ? ? ?
G 1v2 G 1v8 G G ? ? ?
SCL 3v3 G 3v3 G 1v2 1v2 ? ? ?
SDA 1v2 3v3 G 1v8 G 1v8 ? ? ?
? ? G G 1v2 G 1v8 G ? ?
? ? ? 1v8 1v2 G 1v8 G 1v2 ? ?
? ? ? 1v2 G 1v8 G 1v2 1v8 ? ? ?
? ? ? G 1v8 G 1v8 G G ? ? ?
? ? ? 1v8 G 1v8 G 1v8 1v2 ? ? ?
G ? ? 1v2 1v2 G 1v8 G 1v8 G 1v8 G 1v2 G 1v8 G 1v8 G 1v8 G 1v8 ? ? ?
? ? ? G G 1v8 G 1v2 G 1v8 G 1v2 G 1v8 G 1v2 G 1v8 G 1v2 G ? ? ?
? ? ? 1v8 1v2 ? ? ?
? ? ? 1v2 1v8 ? ? ?
? ? ? G 1v8 1v2 G 1v8 1v2 G 1v8 1v2 G 1v8 1v2 G 1v8 1v2 G 1v8 1v2 G 1v8 1v2 G ? ? ?
? ? ? ? ? ? ? ? ? ? 3? 4? 5? B PADR PADD G ? ? G ? ? ? ?
? ? ? ?
G G ? ? ? ? ? ? ? ? SDA 1? 2? A STRT PADU L Y ? ? ? ? ? ? ?
G ? ? ? ? ? ? ? ? SCL 0? SLCT PADL R X ? ? ? ? ? ? G

legend:

SoC clock crystal
RTC clock crystal
Gamecard
SDCARD SDIO
NAND SDIO
WIFI SDIO
SPI
I2C-1
I2C-2
I2C-3
Pad
FCRAM
Camera
WIFI
GPIO
LCD0 (small)
LCD1 (big)
CODEC0 (unknown)
CODEC1 (unknown)
MCU (unknown)
POWER
Ground

Orientation: Triangle bottom right on the PCB.

UC CTR

This MCU seems to be a customized 64 pin FLGA version of this: https://www.renesas.com/ko-kr/doc/products/mpumcu/doc/rl78/r01ds0053ej0330-rl78g14.pdf

The pin layouts are similar, but not the same

Orientation: Pin 1 marker in bottom left corner

Hardware pins

+ G TP75 X X ?
SCL G /RESET ? ? +
SDA + TP77 TP76 +
? TP78 PWRLED1 CHRGLED
G G
PWRBTN BATTTHM
PWRLED0 HOMEBTN
+ SCL SDA G

Software pins

Port ID Pin ID Purpose
020 ?? HOME button
043 ?? Charging LED(?)
051 ?? Charger "button"
073 ?? Power button
074 ?? WiFi button
076 ?? External IRQ (MCU --> SoC)

CODEC

4? 3v3 3? 0? ? ? G
3? 5? G 1? CSx ? G
G 2? 0? G 2? CSy SPEAKER1
TOUCH TOUCH 1? G G G G G G SPEAKER1
TOUCH TOUCH G G G G G G
CPAD CPAD G G G G G G
G G G G G G SPEAKER2
MIC G G G G G G G SPEAKER2
JACK_R G G G G
3v3 G G G G
G JACK_L G G

LCD (old3DS bottom)

Pin number Name Description
01 -6V
02 12V
03 CLK Pixel clock
04 /HBL Horizontal blank (low while blanking)
05 /VBL Vertical blank (low while blanking)
06 2v2 Loopback of pin 07?
07 2v2 Content latch? Shorting this to ground or to pin 06 will "lock" the screen memory while still allowing the screen to refresh itself.
08 GND "chassi" ground
09 HCL Horizontal clock
10 GND "chassi" ground
11 BIAS 1 Default ~ 4.5V - 4.8V; sets contrast
12 BIAS 2 Usually matches BIAS 1; sets "flicker"
13 ??? Might be a transistor? Shorted to ground if off, 2.36V if on.
14 6V
15 ??? Loopback of pin 14 ? Shorting this with pin 14 or ground will make the 3DS turn off with a harsh pop sound.
16 ??? ???
17 ??? ???
18

[...]

25

RED 0

[...]

RED 7

Red pixel bits
26 GND "chassi" ground
27

[...]

34

BLUE 7

[...]

BLUE 0

Blue pixel bits
35 GND "chassi" ground
36

[...]

43

GREEN 7

[...]

GREEN 0

Green pixel bits