EMMC Registers
These registers are used to access the system NAND and the inserted SD card. Both devices use the same interface.
Registers
| Old3DS | Name | Address | Width | Used by |
|---|---|---|---|---|
| Yes | EMMC_CMD | 0x10006000 | 2 | Boot9, NewKernel9Loader, Process9 |
| Yes | ? | 0x10006002 | 2 | |
| Yes | EMMC_CMDARG0 | 0x10006004 | 2 | |
| Yes | EMMC_CMDARG1 | 0x10006006 | 2 | |
| Yes | EMMC_STOP | 0x10006008 | 2 | |
| Yes | EMMC_BLKCOUNT | 0x1000600a | 2 | |
| Yes | EMMC_RESP0-7 | 0x1000600c | 2*8 | |
| Yes | EMMC_STATUS0 | 0x1000601c | 2 | |
| Yes | EMMC_STATUS1 | 0x1000601e | 2 | |
| Yes | ? | 0x10006020 | 2 | |
| Yes | ? | 0x10006022 | 2 | |
| Yes | EMMC_CLKCTL | 0x10006024 | 2 | |
| Yes | EMMC_BLKLEN | 0x10006026 | 2 | |
| Yes | EMMC_OPT | 0x10006028 | 2 | |
| Yes | EMMC_FIFO | 0x10006030 | 2 | |
| Yes | EMMC_RESET | 0x100060E0 | 2 |
The IO interface for SDMC/NAND seems to be very similar to the DSi; see libnds for sample code and documentation, and GBATEK for better documentation.
3DS SDMC/NAND IO registers are located at 0x10006000 and apparently mirrored at 0x10007000. It seems the 0x10007000 mirror is never used on retail units.
EMMC_STATUS0
| Bit | Description |
|---|---|
| 3 | SD card removal flag (Set to 1 when SD card is removed) |
| 4 | SD card insertion flag (Set to 1 when SD card is inserted) |
| 5 | SD card insertion status (0 = missing, 1 = inserted) |
SD card insertion status
Assertion happens around 250 ms after SD card insertion and/or enabling the EMMC hardware (delay could possibly be due to an SD bus timeout?).