NDMA

Registers

There's 4 NDMA channels. Arm7/Arm9 have separate NDMA.

NAME	ADDRESS	WIDTH
REG_NDMA_MASTER_CNT	0x04004100	4
REG_NDMA_SRC(n)	0x04004104 + (n*0x1c)	4
REG_NDMA_DEST(n)	0x04004108 + (n*0x1c)	4
REG_NDMA_NUM0(n)	0x0400410c + (n*0x1c)	4
REG_NDMA_NUM1(n)	0x04004110 + (n*0x1c)	4
REG_NDMA_14(n)	0x04004114 + (n*0x1c)	4
REG_NDMA_CLEAR(n)	0x04004118 + (n*0x1c)	4
REG_NDMA_CNT(n)	0x0400411c + (n*0x1c)	4

REG_NDMA_MASTER_CNT

BIT	DESCRIPTION
15-0	?
16	Unknown, set when initialized by Arm7?
17	Unknown, set when initialized by Arm9?
18	Unknown, set when initialized by Arm7/Arm9?
30-19	?
31	Might be master NDMA enable, when initialized this is set?

REG_NDMA_SRC

BIT	DESCRIPTION
31-0	Source data address.

Like old DMA, REG_NDMA_SRC is copied to internal registers when written to.

REG_NDMA_DEST

BIT	DESCRIPTION
31-0	Destination data address.

Like old DMA, REG_NDMA_DEST is copied to internal registers when written to.

REG_NDMA_NUM0

BIT	DESCRIPTION
31-0	Number of bytes to copy/write, see REG_NDMA_CNT bit28.

REG_NDMA_NUM1

BIT	DESCRIPTION
31-0	Number of bytes to copy/write, see REG_NDMA_CNT bit28.

REG_NDMA_14

BIT	DESCRIPTION
31-0	Time related?

Once the CNT bit31 enable bit is set, starting doing the DMA once the time units specified by this register elapses?

REG_NDMA_CLEAR

BIT	DESCRIPTION
31-0	Value to write to destination instead of copying when REG_NDMA_CNT bit13 and bit14 are set.

REG_NDMA_CNT

BIT	DESCRIPTION
10-0	?
11	Fixed destination address when set.
12	?
13	When set clear data with the value REG_NDMA_CLEAR instead of copying.
14	Fixed source address when set.
27-15	?
28	Set when REG_NDMA_NUM0 was set, clear when REG_NDMA_NUM1 was set.
30	IRQ enable
31	Enable/busy