Gamecards

A 3DS gamecard

Close-up of PCB

Physical interface

The 3DS gamecards have the same physical interface as regular DS and DSi gamecards. There is only a minor cosmetic difference in the plastic case, which has a small extruding notch on the top-right side. As such, it prevents insertion of the gamecard into old Nintendo DS or DSi systems.

When modifying the case so that the 3DS gamecard fits in a DS or DSi system, those systems will refuse to detect the gamecard and show no banner icon.

Pin	Name	Description
1	GND	Ground
2	CLK	Clock. Frequencies 6.7MHz and 4.2MHz)
3	NC	Not connected. Possibly used to program cards.
4	RCS	ROM select, active low. Pulled low to start a ROM transfer.
5	RST	Reset, active low.
6	ECS	Savegame chip select, active low. Pulled low to start a savegame SPI transfer.
7	IRQ	Removal detection.
8	VCC	Powersupply 3.3V.
9	DAT0	Bidirectional data bus.
10	DAT1	Bidirectional data bus.
11	DAT2	Bidirectional data bus.
12	DAT3	Bidirectional data bus.
13	DAT4	Bidirectional data bus.
14	DAT5	Bidirectional data bus.
15	DAT6	Bidirectional data bus / SPI data from savegame chip.
16	DAT7	Bidirectional data bus / SPI data to savegame chip.
17	GND	Ground

Protocol

The communication protocol between the 3DS system and the 3DS gamecard has changed completely in comparison with the DS and DSi gamecard communication protocol.