Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 119

AGB Programming Manual
DMA3CNT_H [d14] Interrupt Request Enable Flag
Enables an interrupt request to be generated when DMA transfer of the
specified word count has been completed.
No request is generated with a setting of 0; a request is generated with a
setting of 1.
DMA3CNT_H [d13 - 12] DMA Startup Timing
The timing of the DMA transfer can selected from the following options.
Setting
00
01
10
11
DMA3CNT_H [d11] Game Pak Data Request Transfer Flag
Should normally be set to 0.
When set to 1, DMA transfer is performed in response to a data request
from the Game Pak.
[Note]
A Game Pak that supports this transfer mode is required in order to use it.
In addition, it cannot be used at the same time as a Game Pak interrupt.
DMA3CNT_H [d10] DMA Transfer Type
Sets the bit length of the transfer data.
With a setting of 0, the data are transferred by DMA in 16-bit (half-word)
units. With a setting of 1, the data are transferred by DMA in 32-bit (word)
units.
©1999 - 2001 Nintendo of America Inc.
Start Immediately
Start During a V-blanking Interval
Starts at the beginning of a V-blanking interval (approximately
4.993 ms).
Start During a H-blanking Interval
Starts at the beginning of a H-blanking interval (approximately
16.212 µs).
If this accompanies OAM access, the H-blanking interval must
first be freed of OBJ display hardware processing periods. (See
"5 Image System".)
Synchronize with display and start.
Synchronize with start of H-Line rendering during a display
interval and start.
119
DMA Startup Timing
DMA Transfer
D.C.N. AGB-06-0001-002B4