3DS NDMA has 8 channels. The first 0x100-bytes of this IO mem is
mirrored at 0x10002100, repeated every 0x100-bytes until the end of the
0x1000-byte IO mem. NDMA can access the Arm9 bootrom, including the
protected part before it is locked out.
Registers
#
NDMA_GLOBAL_CNT
#
Bit | Description |
---|
0 | Global enable? |
19-16 | Cycle selection. |
31 | DMA arbitration method. 0=Fixed method, 1=Round robin |
NDMA_SRC_ADDR
#
Bit | Description |
---|
31-0 | Source data address. Must be multiple of 4. |
Like old DMA, NDMA_SRC_ADDR is copied to internal registers when written
to.
NDMA_DST_ADDR
#
BIT | DESCRIPTION |
---|
31-0 | Destination data address. Must be multiple of 4. |
Like old DMA, NDMA_DST_ADDR is copied to internal registers when written
to.
NDMA_TRANSFER_CNT
#
Bit | Description |
---|
27-0 | Total number of words transferred. |
NDMA_WRITE_CNT
#
Bit | Description |
---|
23-0 | Number of words to transfer. |
NDMA_BLOCK_CNT
#
Bit | Description |
---|
15-0 | Interval timer. |
17-16 | Prescaler. 0=System freq, 1=1/4th freq, 2=1/16th freq, 3=1/64th freq. |
NDMA_FILL_DATA
#
Bit | Description |
---|
31-0 | Fill data. |
NDMA_CNT
#
Bit | Description |
---|
4-0 | Device to device startup mode |
11-10 | Destination address update method. 0=Increment, 1=Decrement, 2=Fixed. |
12 | Destination address reload flag. |
14-13 | Source address update method. 0=Increment, 1=Decrement, 2=Fixed, 3=No address (for filling) |
15 | Source address reload flag. |
19-16 | Block transfer word count = (1<<x) words. |
27-24 | Startup mode. |
28 | Immediate mode. |
29 | Repeating mode. |
30 | IRQ enable |
31 | Enable/busy flag. |
Startup modes (4-0)
#
Value | Description |
---|
0 | TIMER0 |
1 | TIMER1 |
2 | TIMER2 |
3 | TIMER3 |
4 | CTRCARD0 |
5 | CTRCARD1 |
6 | SDIO1 |
7 | SDIO3 |
8 | AES in (
WRFIFO) |
9 | AES out (
RDFIFO) |
10 | SHA in (
INFIFO) |
11 | SHA out (
INFIFO, source data readback mode) |
12 | NTRCARD |
13 | ? |
14 | ? |
15 | Device to device (subclassed by bits 4-0) |
Device to device startup modes (4-0)
#
Value | Description |
---|
0 | CTRCARD0 -> AES |
1 | CTRCARD1 -> AES |
2 | AES -> CTRCARD0 |
3 | AES -> CTRCARD1 |
4 | CTRCARD0 -> SHA |
5 | CTRCARD1 -> SHA |
6 | SHA -> CTRCARD0 |
7 | SHA -> CTRCARD1 |
8 | SDIO1 -> AES |
9 | SDIO3 -> AES |
10 | AES -> SDIO1 |
11 | AES -> SDIO3 |
12 | SDIO1 -> SHA |
13 | SDIO3 -> SHA |
14 | SHA -> SDIO1 |
15 | SHA -> SDIO3 |
16 | AES -> SHA |
17 | SHA -> AES |
Block transfers
#
First, a word is always 32 bits. Second, the block transfer specified in
NDMA_CNT is the smallest atom of data that will be transferred in a
burst. The bus is monopolized until this block is transferred, without
splitting up.
The next block transfer will happen after the specified time in the
NDMA_BLOCK_CNT interval timer, until done.
Transfers the words specified in NDMA_WRITE_CNT immediately following
block transfer rules. NDMA_TRANSFER_CNT and repeating mode are ignored.
Repeating mode
#
Transfers the words specified in NDMA_WRITE_CNT following the startup
mode event. NDMA_TRANSFER_CNT is ignored.
Transfers the words specified in NDMA_WRITE_CNT for each startup event,
and gets disabled when the total number of words in NDMA_TRANSFER_CNT
are transferred.