SPI Registers
Revision as of 19:36, 7 May 2019 by Profi200 (talk | contribs) (→Registers: Use same naming scheme as NDMA)
Registers
Old3DS | Name | Address | Width | Used by |
---|---|---|---|---|
Yes | SPI_CNT0 | 0x10142000 | 2 | |
Yes | SPI_DATA0 | 0x10142002 | 1 | |
Yes | NSPI_CNT0 | 0x10142800 | 4 | |
Yes | NSPI_DONE0 | 0x10142804 | 4 | |
Yes | NSPI_BLKLEN0 | 0x10142808 | 4 | |
Yes | NSPI_FIFO0 | 0x1014280C | 4 | |
Yes | NSPI_STATUS0 | 0x10142810 | 4 | |
Yes | ? Same as SPICARD + 0x814. Unused by SPI sysmodule. | 0x10142814 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x10142818 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x1014281C | 4 | |
Yes | SPI_CNT1 | 0x10143000 | 2 | |
Yes | SPI_DATA1 | 0x10143002 | 1 | |
Yes | NSPI_CNT1 | 0x10143800 | 4 | |
Yes | NSPI_DONE1 | 0x10143804 | 4 | |
Yes | NSPI_BLKLEN1 | 0x10143808 | 4 | |
Yes | NSPI_FIFO1 | 0x1014380C | 4 | |
Yes | NSPI_STATUS1 | 0x10143810 | 4 | |
Yes | ? Same as SPICARD + 0x814. Unused by SPI sysmodule. | 0x10143814 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x10143818 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x1014381C | 4 | |
Yes | SPI_CNT2 | 0x10160000 | 2 | |
Yes | SPI_DATA2 | 0x10160002 | 1 | |
Yes | NSPI_CNT2 | 0x10160800 | 4 | |
Yes | NSPI_DONE2 | 0x10160804 | 4 | |
Yes | NSPI_BLKLEN2 | 0x10160808 | 4 | |
Yes | NSPI_FIFO2 | 0x1016080C | 4 | |
Yes | NSPI_STATUS2 | 0x10160810 | 4 | |
Yes | ? Same as SPICARD + 0x814. Unused by SPI sysmodule. | 0x10160814 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x10160818 | 4 | |
Yes | ? Unused by SPI sysmodule. | 0x1016081C | 4 |
There are two register interfaces: the old NDS/DSi one and an alternative faster interface introduced with the 3DS.
To toggle between those interfaces, use the CFG11_SPI_CNT register.
SPI_CNT
This is the old NDS/DSi SPI interface.
Bits | Name |
---|---|
0-1 | Baudrate (0=4MHz, 1=2MHz, 2=1MHz, 3=512KHz) |
2-6 | This was added with 3DS. |
7 | Busy Flag (0=Ready, 1=Busy) (presumably Read-only) |
8-9 | Device Select (0=Powerman., 1=Firmware, 2=Touchscreen) |
10 | Transfer Size (0=8bit/Normal, 1=16bit/Bugged) |
11 | Chipselect Hold (0=Deselect after transfer, 1=Keep selected) |
12-13 | Not used (Zero) |
14 | Interrupt Request (0=Disable, 1=Enable) |
15 | SPI Bus Enable (0=Disable, 1=Enable) |
NSPI_CNT
This is an alternative faster interface introduced with the 3DS.
Bits | Name |
---|---|
0-2 | Baudrate? |
6-7 | Device Select |
12 | Bus mode 0=1 bit, 1=4 bit |
13 | Transfer Direction? (0=Incoming, 1=Outgoing) |
15 | Busy/enable |
Device id | Device select bits |
---|---|
0, 3, >=6 | 0 |
1, 4 | 1 |
2, 5 | 2 |
Device id | Used baudrate |
---|---|
3 | 5 |
0 | 2 |
NSPI_DONE
This register reads as 1 after starting a transfer. When the transfer is finished, a 0 has to be written to this register. This is probably the Chip Select line.
NSPI_BLKLEN
The number of bytes to be sent/read is written to this register.
NSPI_FIFO
32-bit FIFO for reading/writing the SPI payload.
NSPI_STATUS
Bit0: FIFO busy. At transfer start and every 32 bytes the FIFO becomes busy.