Nintendo 1504166 - Game Boy Advance SP Edition Console Programming Manual page 111

AGB Programming Manual
DMA0CNT_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.
DMA0CNT_H [d13 - 12] DMA Startup Timing
The timing of the DMA transfer can selected from the following options.
Setting
00
01
10
11
DMA0CNT_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.
DMA0CNT_H [d09] DMA Repeat
With the DMA repeat function set to ON, if V-blanking or H-blanking
intervals are selected as the timing of DMA startup, DMA is restarted when
the next startup condition occurs (a V-blank or H-blank). In this mode,
restarting will continue as long as the DMA enable flag is not set to 0.
When the DMA repeat function is set to OFF, DMA halts as soon as the
amount of data specified by the value in the word-count register has been
transferred.
©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 s).
If this accompanies OAM access, the H-blanking interval must
first be freed of OBJ display hardware processing periods. (See
"5 Image System".)
Prohibited Code
111
DMA Startup Timing
DMA Transfer
D.C.N. AGB-06-0001-002B4