Registers
There's 4 NDMA channels. Arm7/Arm9 have separate NDMA.
NAME
|
ADDRESS
|
WIDTH
|
REG_NDMAGCNT
|
0x04004100
|
4
|
REG_NDMASAD(n)
|
0x04004104 + (n*0x1c)
|
4
|
REG_NDMADAD(n)
|
0x04004108 + (n*0x1c)
|
4
|
REG_NDMATCNT(n)
|
0x0400410c + (n*0x1c)
|
4
|
REG_NDMAWCNT(n)
|
0x04004110 + (n*0x1c)
|
4
|
REG_NDMABCNT(n)
|
0x04004114 + (n*0x1c)
|
4
|
REG_NDMAFDATA(n)
|
0x04004118 + (n*0x1c)
|
4
|
REG_NDMACNT(n)
|
0x0400411c + (n*0x1c)
|
4
|
REG_NDMAGCNT
BIT
|
DESCRIPTION
|
19-16
|
Cycle selection.
|
31
|
DMA arbitration method. 0=Fixed method, 1=Round robin
|
REG_NDMASAD
BIT
|
DESCRIPTION
|
31-0
|
Source data address. Must be multiple of 4.
|
Like old DMA, REG_NDMASAD is copied to internal registers when written to.
REG_NDMADAD
BIT
|
DESCRIPTION
|
31-0
|
Destination data address. Must be multiple of 4.
|
Like old DMA, REG_NDMADAD is copied to internal registers when written to.
REG_NDMATCNT
BIT
|
DESCRIPTION
|
27-0
|
Total number of words transferred.
|
REG_NDMAWCNT
BIT
|
DESCRIPTION
|
23-0
|
Number of words to transfer.
|
REG_NDMABCNT
BIT
|
DESCRIPTION
|
15-0
|
Interval timer.
|
17-16
|
Prescaler. 0=System freq, 1=1/4th freq, 2=1/16th freq, 3=1/64th freq.
|
REG_NDMAFDATA
BIT
|
DESCRIPTION
|
31-0
|
Fill data.
|
REG_NDMACNT
BIT
|
DESCRIPTION
|
11-10
|
Destination address update method.
|
12
|
Destination address reload flag.
|
14-13
|
Source address update method.
|
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 (27-24)
BIT
|
DESCRIPTION
|
0
|
Timer 0
|
1
|
Timer 1
|
2
|
Timer 2
|
3
|
Timer 3
|
4
|
Game Card
|
6
|
V-Blank
|
7
|
H-Blank
|
8
|
Display
|
9
|
Work RAM
|
10
|
Geometry FIFO
|
11
|
Camera
|