SPI Registers

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Registers[edit]

Old3DS Name Address Width Used by
Yes SPI_CNT0 0x10142000 2
Yes SPI_DATA0 0x10142002 1
Yes SPI_NEW_CNT0 0x10142800 4
Yes SPI_NEW_DONE0 0x10142804 4
Yes SPI_NEW_BLKLEN0 0x10142808 4
Yes SPI_NEW_FIFO0 0x1014280C 4
Yes SPI_NEW_STATUS0 0x10142810 4
Yes SPI_CNT1 0x10143000 2
Yes SPI_DATA1 0x10143002 1
Yes SPI_NEW_CNT1 0x10143800 4
Yes SPI_NEW_DONE1 0x10143804 4
Yes SPI_NEW_BLKLEN1 0x10143808 4
Yes SPI_NEW_FIFO1 0x1014380C 4
Yes SPI_NEW_STATUS1 0x10143810 4
Yes SPI_CNT2 0x10160000 2
Yes SPI_DATA2 0x10160002 1
Yes SPI_NEW_CNT2 0x10160800 4
Yes SPI_NEW_DONE2 0x10160804 4
Yes SPI_NEW_BLKLEN2 0x10160808 4
Yes SPI_NEW_FIFO2 0x1016080C 4
Yes SPI_NEW_STATUS2 0x10160810 4

SPI_CNT[edit]

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)

SPI_NEW_CNT[edit]

This is an alternative faster interface introduced with the 3DS.

Bits Name
0-5 Baudrate?
6-7 Device Select
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

SPI_NEW_DONE[edit]

When the transfer is finished, a 0 has to be written to this register.

SPI_NEW_BLKLEN[edit]

The number of bytes to be sent/read is written to this register.

SPI_NEW_FIFO[edit]

32-bit FIFO for reading/writing the SPI payload.

SPI_NEW_STATUS[edit]

Bit0: FIFO busy.