I2C Service Names #
| Service names | Notes | Accessible deviceIDs | Service used by sysmodule |
|---|---|---|---|
| “i2c::MCU” | 0, 3 | MCU | |
| “i2c::CAM” | 1, 2, 4 | Camera | |
| “i2c::LCD” | 5, 6 | GSP | |
| “i2c::DEB” | 7, 8 | Unknown | |
| “i2c::HID” | 9, 10, 11, 12 | HID | |
| “i2c::IR” | 13, and additionally for New3DS i2c module: 17 | IR | |
| “i2c::EEP” | 14 | Cfg | |
| “i2c::NFC” | Only available via the New3DS i2c sysmodule. | 15 | New3DS NFC |
| “i2c::QTM” | Only available via the New3DS i2c sysmodule. | 16 | New3DS QTM |
Each I2C service can only access certain I2C device(s). When the specified deviceid isn’t accessible, error 0xE0A02FEA is returned.
I2C Service #
| Command Header | Available since system-version | Description |
|---|---|---|
| 0x00010100 | SetRegisterBits8 (u8 devid, u8 regid, u8 regdata, u8 mask) | |
| 0x000200C0 | EnableRegisterBits8 (u8 devid, u8 regid, u8 enablemask) | |
| 0x000300C0 | DisableRegisterBits8 (u8 devid, u8 regid, u8 disablemask) | |
| 0x00040102 | MultiSetRegisterBits16 (u16 regid, u16 regdata, u16 mask, devcount, u8* devidlistptr) | |
| 0x000500C0 | WriteRegister8 (u8 devid, u8 regid, u8 regdata) | |
| 0x00060080 | WriteCommand8 (u8 devid, u8 cmdid) | |
| 0x000700C0 | WriteRegister16 (u8 devid, u8 regid, u16 regdata) | |
| 0x000800C2 | MultiWriteRegister16 (u16 regid, u16 regdata, devcount, u8* devidlistptr) | |
| 0x00090080 | u8 ReadRegister8 (u8 devid, u8 regid) | |
| 0x000A0080 | u16 ReadRegister16 (u8 devid, u8 regid) | |
| 0x000B00C2 | WriteRegisterBuffer8 (u8 devid, u8 regid, buffersize, (buffersize << 14) | 0x402, u8* bufferptr) | |
| 0x000C00C2 | WriteRegisterBuffer16 (u8 devid, u16 regid, buffersize, (buffersize << 15) | 0x402, u16* bufferptr) | |
| 0x000D00C0 | ReadRegisterBuffer8 (u8 devid, u8 regid, buffersize, +0x180: (buffersize << 14) | 2, +0x184: u8 bufferptr) | |
| 0x000E00C2 | WriteRegisterBuffer (u8 devid, u8 regid, unused (bufsize?), (bufsize << 14) | 0x402, void* buffer) | |
| 0x000F00C0 | ReadRegisterBuffer (u8 devid, u8 regid, min(bufsize, 0x20)), +0x180: (bufsize << 14) | 2, void* buffer | |
| 0x001000C0 | ReadEEPROM (u8 devid = 14, u16 blockid, min(bufsize >> 1, 0x10)), +0x180: (bufsize << 15) | 2, u16* buffer | |
| 0x001100C2 | WriteRegisterBuffer(u8 devid, u8 regid, buffersize, u8 *buff) | |
| 0x001200C2 | ReadRegisterBuffer(u8 devid, u8 regid, buffersize, u8 *buff) | |
| 0x00130040 | 8.0.0-18 | ReadDeviceRaw8(u8 devid) Writes the output read u8 I2C data to cmdreply[2]. After successfully selecting the I2C device, it writes 0xE1 to CNT then loads the output u8 I2C data from the DATA register. |
| 0x00140082 | 8.0.0-18 | WriteDeviceRaw(u8 devid, u32 buffersize, (buffersize << 14) | 0x402, bufferptr) This is basically the write-data version of command 0x00150080. |
| 0x00150080 | 8.0.0-18 | ReadDeviceRaw(u8 devid, u32 buffersize, +0x180: (buffersize << 14) | 2, +0x184: bufferptr) This is the >1-byte version of command 0x00130040, except value 0xF0 is used for CNT instead of 0xE1. |
Commands 0x00130040..0x00150080 are only usable with the New3DS i2c module: on Old3DS the actual command-handler function for each of these commands just return an error. Commands 0x00140082 and 0x00150080 are used by NFC module. Command 0x00150080 is also used for reading ZL, ZR, and C-stick data by IR Services.