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. 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(?)
|
| 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) for ARM9
| 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
|